| 1. |
- Broxvall, Mathias, 1976-, et al.
(författare)
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Fast GPU based adaptive filtering of 4D echocardiography
- 2012
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Ingår i: IEEE Transactions on Medical Imaging. - Piscataway, USA : Institute of Electrical and Electronics Engineers (IEEE). - 0278-0062 .- 1558-254X. ; 31:6, s. 1165-1172
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Tidskriftsartikel (refereegranskat)abstract
- Time resolved three-dimensional (3D) echocardiography generates four-dimensional (3D+time) data sets that bring new possibilities in clinical practice. Image quality of four-dimensional (4D) echocardiography is however regarded as poorer compared to conventional echocardiography where time-resolved 2D imaging is used. Advanced image processing filtering methods can be used to achieve image improvements but to the cost of heavy data processing. The recent development of graphics processing unit (GPUs) enables highly parallel general purpose computations, that considerably reduces the computational time of advanced image filtering methods. In this study multidimensional adaptive filtering of 4D echocardiography was performed using GPUs. Filtering was done using multiple kernels implemented in OpenCL (open computing language) working on multiple subsets of the data. Our results show a substantial speed increase of up to 74 times, resulting in a total filtering time less than 30 s on a common desktop. This implies that advanced adaptive image processing can be accomplished in conjunction with a clinical examination. Since the presented GPU processor method scales linearly with the number of processing elements, we expect it to continue scaling with the expected future increases in number of processing elements. This should be contrasted with the increases in data set sizes in the near future following the further improvements in ultrasound probes and measuring devices. It is concluded that GPUs facilitate the use of demanding adaptive image filtering techniques that in turn enhance 4D echocardiographic data sets. The presented general methodology of implementing parallelism using GPUs is also applicable for other medical modalities that generate multidimensional data.
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| 2. |
- Dimitriou, Praxitelis, et al.
(författare)
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Cardiovascular magnetic resonance imaging and transthoracic echocardiography in the assessment of stenotic aortic valve area : a comparative study
- 2012
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Ingår i: Acta Radiologica. - London, United Kingdom : Royal Society of Medicine Press. - 0284-1851 .- 1600-0455. ; 53:9, s. 995-1003
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Tidskriftsartikel (refereegranskat)abstract
- Background: Magnetic resonance (MR) imaging and echocardiography both allow assessment of aortic valve stenosis. In MR the aortic valve area (AvA) is measured using planimetry while in transthoracic echocardiography (TTE) AvA is usually calculated by applying the continuity equation.Purpose: To compare the measured stenotic aortic valve areas using five different MR-acquisition alternatives with the corresponding area values calculated by TTE.Material and Methods: The aortic valve was imaged in 14 patients, with diagnosed aortic valve stenosis, using balanced steady state free precession (bSSFP) gradient echo (GE) and phase contrast imaging (PC). Three adjacent slices were planned to encompass the aortic valve and the aortic valve area was measured using planimetry. The two sets of complex valued images generated by the PC sequence formed three kinds of images that could be used for aortic valve area measurements: the magnitude image (PC/Mag), the modulus (PCA/M), and phase difference (PCA/P) between the two complex images, respectively. The valve area from TTE was calculated using the continuity equation. A cut-off of <1.0 cm(2) was used as a criteria for severe stenosis.Results: The mean area differences between the different MR acquisitions and TTE method were -0.05 ± 0.37 cm(2) (GE), -0.18 ± 0.46 cm(2) (bSSFP), 0.27 ± 0.43 cm(2) (PC/Mag), 0.15 ± 0.32 cm(2) (PCA/P), and 0.26 ± 0.27 cm(2) (PCA/M). The valve area was significantly overestimated using PCA/M that, in turn, implied a significant underestimation of the aortic valve stenosis severity compared to the assessments using TTE.Conclusion: The smallest area valve difference between TTE and an MR-acquisition alternative is obtained with gradient echo images. The use of PCA/M leads to significant differences in planimetry measurements of the aortic valve orifice and the gradation of the stenosis severity compared to TTE.
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| 3. |
- Emilsson, Kent, 1963-, et al.
(författare)
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An unusual cause of high threshold values at pacemaker implantation
- 1997
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Ingår i: Pacing and Clinical Electrophysiology. - : John Wiley & Sons. - 0147-8389 .- 1540-8159. ; 20:Part: 1, s. 366-7
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Tidskriftsartikel (refereegranskat)abstract
- An 81-year old man with third-degree AV block and weakness underwent an unsuccessful attempt to DDD pacemaker implant caused by hypothyroidism. Administration of thyroxin until he was euthyroid permitted implantation with normal stimulation thresholds.
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| 4. |
- Emilsson, Kent, 1963-
(författare)
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Can the amplitude of mitral annulus motion be used in the assessment of left ventricular systolic function in patients with left ventricular wall thickness in the upper limit of normal to mild hypertrophy?
- 2003
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Ingår i: Experimental and clinical cardiology. - 1205-6626. ; 8:1, s. 29-30
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mitral annulus motion (MAM) obtained by echocardiography can be used in the assessment of left ventricular systolic function (LVSF). However, it has been shown that the amplitude of MAM is decreased in patients with left ventricular wall thickness (LVWT) greater than 14 mm.OBJECTIVE: To study if the amplitude of MAM can be used in the assessment of LVSF in patients with LVWT in the upper limit of normal to mild hypertrophy (12 mm to 14 mm).METHODS: Eighteen consecutive patients with LVWT of 12 mm to 14 mm were compared to 18 age- and sex-matched patients with LVWT less than 12 mm.RESULTS: There was no significant difference between the amplitude of MAM in the two groups.CONCLUSIONS: MAM can be used in the assessment of LVSF in patients with LVWT in the upper limit of normal to mild hypertrophy and be related to reference values.
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| 5. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Comparison between angiographic right coronary artery motion and echocardiographic tricuspid annulus motion
- 2004
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 38:2, s. 85-92
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare echocardiographic M-mode measurements of tricuspid annulus motion (TAM) with angiographic M-mode measurements of right coronary artery motion (RAM).DESIGN: Twenty-four patients were included and examined by echocardiography before the angiographic examination. The amplitudes and the velocities of TAM and the atrial contribution to the total amplitude of TAM were measured. The obtained values were compared with angiographic M-mode measurements of RAM at a proximal and a distal site of the second segment of the right coronary artery.RESULTS: There was no significant difference between several of the echocardiographic M-mode measurements of TAM and the angiographic M-mode measurements of RAM. However, the agreement was rather poor for some variables.CONCLUSION: Different parameters obtained from echocardiographic TAM are not interchangeable with values from angiographic RAM. If measurements of RAM are to be used in the assessment of right ventricular (RV) function further studies are needed to examine the correlation and agreement between RAM and different methods of measuring RV function, i.e. radionuclide angiography or magnetic resonance imaging.
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| 6. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Comparison between aortic annulus motion and mitral annulus motion obtained using echocardiography
- 2006
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 26:5, s. 257-262
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies have shown that the aortic root, in analogy with the mitral annulus, moves towards the left ventricular apex during systole. However, there are no earlier studies comparing the amplitude of the aortic annulus motion (AAM) with that of the mitral annulus (MAM), which was the main aim of the study. Another aim was to study the intra- and interobserver reproducibility (IIOR) of measuring AAM with M-mode and 2-D echocardiography as it is not obvious which of the methods that should be used. Twenty-one healthy subjects were examined by echocardiography. AAM and MAM were measured at different sites. IIOR was measured in 10 of the subjects. There was no significant difference between average AAM (15.3 +/- 1.5 mm) and average MAM (15.6 +/- 1.5 mm) and there was a rather good agreement between the variables. There was also no significant difference between AAM at the septal site (16.3 +/- 2 mm) and average MAM, but a significant difference between AAM at the lateral site (14.2 +/- 1.6 mm) and average MAM (P<0.001) and between the both sites of measuring AAM (P<0.001). The significant difference between the two sites of measuring AAM may have anatomical reasons but may also depend on difficulties in measuring AAM at the septal site where it has lower reproducibility than at the lateral site. IIOR of measuring AAM was good when using M-mode but poor when using 2-D echocardiography and AAM should preferably be measured using M-mode and not using 2-D echocardiography.
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| 7. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Comparison between aortic, mitral and tricuspid annular velocities measured with quantitative two-dimensional color Doppler tissue imaging in healthy subjects.
- 2007
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 27:5, s. 275-83
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To compare the systolic, early and late diastolic velocities of the aortic, mitral and tricuspid annuli in healthy subjects and to study the intraobserver and interobserver reproducibility (IIOR) of measuring the velocities at the aortic annulus.METHODS: Twenty healthy subjects with mean age 28 years were investigated with quantitative two-dimensional color Doppler tissue imaging and the systolic, early and late diastolic velocities were measured at the aortic, mitral and tricuspid annuli.RESULTS: The mitral annulus had significant higher systolic velocity and early diastolic velocity than the aortic annulus. The late diastolic velocity was significant lower at the aortic annulus compared with the both other annuli. At the different sites of the annuli the highest systolic velocity and early diastolic velocity were measured at the lateral site of the mitral annulus, whereas the lowest systolic velocity was measured at the septal site of the same annulus. The lowest early diastolic velocity was found at the septal site of the aortic annulus. The highest late diastolic velocity was measured at the lateral site of the tricuspid annulus and the lowest at the lateral site of the aortic annulus.CONCLUSIONS: The mitral annulus has statistical significant higher systolic and early diastolic velocities than the aortic annulus. There are significant differences in velocities between several of the different sites of the annuli. IIOR of measuring the systolic and early diastolic velocities of the aortic annulus is good.
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| 8. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Comparison between circumflex artery motion and mitral annulus motion.
- 2001
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 35:5, s. 318-325
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare mitral annulus motion (MAM) with circumflex artery motion (CXM) and the motion amplitude at an endocardial site (representing MAM) with an epicardial site (representing CXM) at the most basal lateral part of the atrioventricular plane (AVP).DESIGN: MAM and CXM were obtained in 28 patients examined by echocardiography and coronary angiography. The motion amplitude epicardially and endocardially was recorded by echocardiography in 13 patients with normal ejection fraction (EF) (> or = 0.50) and in 13 patients with decreased EF (<0.50).RESULTS: CXM was higher than MAM in most patients with normal EF but lower than MAM in most patients with decreased EF. The motion amplitude epicardially was significantly higher (p < 0.001) than endocardially in patients with normal EF. while there was no significant difference in patients with decreased EF.CONCLUSION: CXM represents the motion of the epicardial part of the AVP and differs from MAM, which represents the endocardial part of the wall. This must be considered when CXM is used for assessment of left ventricular systolic function.
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| 9. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Comparison between maximal early diastolic velocity in long-axis direction obtained by M-mode echocardiography and by tissue Doppler in the assessment of right ventricular diastolic function
- 2005
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Ingår i: Clinical Physiology and Functional Imaging. - Oxford : Blackwell. - 1475-0961 .- 1475-097X. ; 25:3, s. 178-182
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Tidskriftsartikel (refereegranskat)abstract
- Recently the maximal early diastolic velocity in long-axis direction of the right ventricle (RV) obtained by tissue Doppler imaging (MDV TDI) has been introduced in the assessment of RV diastolic function (RVDF). There are reasons to think that also the maximal early diastolic velocity in long-axis direction of the RV obtained using M-mode echocardiography (MDV TAM) could be used to assess RVDF. Therefore, 29 patients were examined with echocardiography and MDV TAM and MDV TDI were measured and compared. A good correlation (r = 0.76, P< 0.001) was found between MDV TAM and MDV TDI indicating that MDV TAM might be used in the assessment of RVDF. However, the velocities obtained by MDV TDI (126.7 &PLUSMN; 38.9 mm s(-1)) were significantly (P< 0.001) higher than the velocities obtained by MDV TAM (78.3 &PLUSMN; 27.8 mm s(-1)) and the agreement between MDV TAM and MDV TDI was rather poor probably mainly due to differences in the measuring technique. This means that reference values cannot be used interchangeably between MDV TAM and MDV TDI. If MDV TAM is going to be used in the assessment of RVDF new reference values have to be produced if today's technique and recommendations to measure MDV TAM and MDV TDI are used. However, as most new echocardiographs are equipped with PW-TDI technology it seems preferable to use this technique and compare obtained values with already established reference values.
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| 10. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Isovolumetric relaxation time of the right ventricle assessed by tissue Doppler imaging
- 2004
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Ingår i: Scandinavian Cardiovascular Journal. - Oslo : Taylor& Francis. - 1401-7431 .- 1651-2006. ; 38:5, s. 278-282
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Tidskriftsartikel (refereegranskat)abstract
- Objectives-The isovolumetric relaxation time of the right ventricle (RV-IVRT) can be assessed using a method based on ECG and pulsed wave Doppler (PW). Recently pulsed wave Doppler tissue imaging (PW-DTI) has been introduced in the assessment.Design-RV-IVRT obtained by the two methods was compared in 20 consecutive patients as was the time from the R wave on the ECG to the onset of tricuspid flow (R-T), to the closure of the pulmonic valve (R-P), to the onset of early diastolic motion of the tricuspid annulus tissue (R-E) and to the end of the systolic motion (R-S).Results-RV-IVRT obtained by the PW method was significantly (p<0.001) shorter than RV-IVRT obtained by PW-DTI. R-S had significantly (p<0.001) shorter duration than R-P, while there was no significant difference between R-E and R-T.Conclusions-The methods are not measuring the same interval. Only the PW method measures RV-IVRT according to the usual definition. Different reference values have to be used if the methods are used in the assessment of RV diastolic function.
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| 11. |
- Emilsson, Kent, 1963-
(författare)
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Mitral annulus motion in left ventricular pumping
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis focus on the role of the mitral annulus motion (MAM) versus outer contour changes in the short axis, in left ventricular (LV) pumping. The influence of atrial contraction on LV dimensions and volumes and the relation between MAM and ejection fraction (EF) in sinus rhythm and in atrial fibrillation was also studied.Echocardiography was used in all studies and in the study about circumflex artery motion angiography was also used.In a study including 20 healthy adults the role of MAM, i.e. the systolic shortening of the left ventricle in the long axis, as the main mechanism of LV pumping was confirmed. There was also, however, a significant contribution to the stroke volume from an outer contour decrease in the short axis during systole. At the chordae tendineae level a cross sectional area decrease of 24% was measured. From calculations based on measures of the long axis shortening of the LV, the outer short axis diameter of the LV and calculated stroke volume, a mean systolic cross sectional area decrease of about 6% was found along the whole length of the ventricle. The higher cross-sectional area decrease at the chordae level is thougth to be caused by regional differences.In previous studies the relation between EF and MAM has been assumed to be linear, but in a meta-analysis of 434 patients it was shown that the relation is non-linear and that a linear regression model overestimates EF in the low range of MAM. It was shown that the relation between EF and MAM in adults is influenced by age but only in the normal range of EF or MAM and not in patients with decreased EF (EF <0.5 or MAM < 10mm). The relation was also shown to be influenced by the LV wall thickness.In 20 patients with atrial fibrillation the ratio EF/MAM was shown to be higher than in 20 age- and gender matched patients with sinus rhythm, due to a decrease in MAM, caused by the loss of atrial contraction.The relation between EF and MAM is thus complex and it therefore seems logical not to "translate" MAM to EF. MAM should be used as such related to reference values in the assessment of LV systolic function.In 13 patients who had atrial fibrillation the stroke volume was shown to increase after successful direct-current cardioversion due to an increase in long axis diastolic elongation of the LV and thereby increased diastolic volume, when atrial contraction was regained.In 28 patients the angiographic measure of circumflex artery motion amplitude tended to be higher than MAM in the higher range of amplitudes while the opposite was found in the lower range of amplitudes.In 13 patients with normal EF it was shown that the motion amplitude of a site epicardially at the most basal lateral part of the LV wall was significantly (P < 0.001) higher than endocardially, but in 13 patients with decreased EF (< 0.5) there was no significant difference between the two sites. The motion amplitude epicardially corresponds to the motion amplitude of the circumflex artery.In the 13 patients with normal EF the motion amplitude of the closed mitral valves was significantly lower than the motion amplitude epi- and endocardially during systole, with a rather conic shape of the atrioventricular plane at the onset of systole. In end-systole the different parts of the left atrioventricular plane, the epicardial part, the endocardial part (mitral annulus) and the valves were almost on the same level.
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| 12. |
- Emilsson, Kent, 1963-, et al.
(författare)
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Outer contour and radial changes of the cardiac left ventricle : a magnetic resonance imaging study.
- 2007
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Ingår i: Clinical Research in Cardiology. - : Springer Science and Business Media LLC. - 1861-0684 .- 1861-0692. ; 96:5, s. 272-278
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies have shown a +/-5% end-systolic decrease in the volume encompassed by the pericardial sack, manifesting as a radial diminution of the pericardial/epicardial contour of the left ventricle (LV). The aim of this study was to measure this radial displacement at different segmental levels of the LV and try to find out were it is as greatest and to calculate regional myocardial volume changes as a reference in healthy subjects. Eleven healthy subjects were examined by magnetic resonance imaging. Images were acquired using an ECG-triggered balanced fast field echo pulse sequence. The epicardial borders of the LV wall were delineated in end-diastole (ED) and end-systole (ES). Regional changes of the LV wall were analysed at three different levels (base, mid and apex) by dividing the myocardium into segments. The volumes obtained as the differences between the outer volume of the left ventricle at ED and ES at different slice levels were found to be greatest at the base of the heart and lowest at apex. The relative inward motion, that is the motion in short-axis direction of the epicardial border of the myocardium from ED to ES towards the centre of the LV, was greatest at the base and lowest at the mid level, something that has to be taken into account when measuring the LV during clinical exams. There was a significant difference in the relative inward motion between the segments at apex (p < 0.0001), mid (p = 0.036) and at base level (p < 0.0001).
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| 13. |
- Emilsson, Kent, 1963-
(författare)
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Right ventricular long-axis function in relation to left ventricular systolic function
- 2004
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 24:4, s. 212-215
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Tidskriftsartikel (refereegranskat)abstract
- A decrease in left ventricular (LV) systolic function is accompanied by a decrease in maximal relaxation velocity in LV long-axis direction, but is it also accompanied by a decrease in right ventricular (RV) long-axis function? To study this 35 consecutive patients were examined by echocardiography. Ejection fraction (LVEF) and mitral annulus motion (MAM) were used as indices of LV systolic function and tricuspid annulus motion (TAM), that is the systolic shortening in RV long-axis direction, was used as an index of RV systolic long-axis function. In the same way the maximal relaxation velocity in LV long-axis direction, that is the maximal diastolic velocity of MAM (MDV MAM), has been suggested as an index of LV diastolic function the maximal diastolic velocity of TAM (MDV TAM) can be supposed to be an index of RV diastolic function measuring the maximal relaxation velocity in the RV long-axis direction. A significant positive correlation was found between MDV TAM and MAM (r = 0.64, P<0001) and LVEF (r = 0.54, P = 0.001) and between TAM and the two studied indices of LV systolic function, with the highest correlation to MAM (r = 0.68, P<0.001) and the lowest to LVEF (r = 0.57, P<0.001). Thus, a decrease in LV systolic function is accompanied by a decrease in both systolic and diastolic RV long-axis function, findings that probably are due to the close anatomical connection between the ventricles and to changes that occur in afterload of the RV secondary to LV systolic dysfunction.
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| 14. |
- Emilsson, Kent, 1963-
(författare)
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Suspected association of ventricular arrhythmia with air pollution in a motorbike rider : a case report
- 2008
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Ingår i: Journal of Medical Case Reports. - : Springer Science and Business Media LLC. - 1752-1947. ; 2, s. 192-
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Premature ventricular complexes are to some extent a normal finding in healthy individuals and the prevalence increases with age and is more common in men. Premature ventricular complexes can occur in association with a variety of stimuli, and a lesser known cause is the association between air pollution and ventricular arrhythmias.CASE PRESENTATION: A previously healthy man started to ride a lightweight motorbike in heavy traffic. A few weeks later he was admitted to hospital with premature ventricular complexes in bigeminy, which decreased after a few days when he was not exposed to exhaust fumes. A few weeks later he started using the motorbike again and the same symptoms developed once more, only to subside when he stopped riding in heavy traffic.CONCLUSION: Studies have shown an association between air pollution and premature ventricular complexes and other kinds of arrhythmias. The mechanism may be changes in cardiac autonomic function, including heart rate and heart rate variability. Air pollution should be considered when patients present with arrhythmias and no other causes are found.
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| 15. |
- Emilsson, Kent, 1963-, et al.
(författare)
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The mode of left ventricular pumping : is there an outer contour change in addition to the atrioventricular plane displacement?
- 2001
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Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 21:4, s. 437-446
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Tidskriftsartikel (refereegranskat)abstract
- The outer contour of the heart has in some studies been shown to be constant during the heart cycle and the epicardial apex almost stationary whilst the base of the ventricles moves towards apex during systole. The base of the left ventricle has been regarded as a cylinder with constant cross-sectional area with changes in height during the heart cycle, the latter corresponding to the amplitude of mitral annulus motion (MAM). In this echocardiographic study, including 20 healthy adults, the stroke volume calculated by the cylinder model was significantly lower than by a reference method (modified Simpson's rule). MAM explained 82% of the stroke volume and 18% must, therefore, be explained by an inward motion of the outer left ventricular wall. A mean outer diameter shortening of about 3% (about 2 mm) was calculated.
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| 16. |
- Emilsson, Kent, 1963-, et al.
(författare)
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The relation between ejection fraction and mitral annulus motion before and after direct-current electrical cardioversion.
- 2000
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Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 20:3, s. 218-24
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Tidskriftsartikel (refereegranskat)abstract
- Mitral annulus motion (MAM) and the relation between left ventricular ejection fraction (EF) and MAM has been shown to differ between patients with sinus rhythm and patients with atrial fibrillation. However, it has not been investigated how the relation between EF and MAM changes on direct-current (DC) electrical cardioversion to sinus rhythm. Therefore, 31 consecutive patients on the waiting list for DC electrical cardioversion were examined by echocardiography before DC electrical cardioversion, and those who maintained sinus rhythm (13 patients) were examined again 4-8 weeks after cardioversion. The conversion factor (CF) (ratio EF/MAM) decreased from 8.4 +/- 1.7 before to 5.8 +/- 0.8 SD after cardioversion (P<0.001). The EF increased slightly (P<0.05) but the MAM had a much greater increase (P<0.001), resulting in the decrease in CF. There was no significant difference in CF between patients after cardioversion and age- and gender-matched control patients with sinus rhythm, indicating that CF is normalized or almost normalized 4-8 weeks after cardioversion. This indicates that when MAM is used for investigation of the left ventricular function, and the function is expressed as EF, the same CF as in other patients with sinus rhythm can be used 4-8 weeks after DC electrical cardioversion.
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| 17. |
- Emilsson, Kent, 1963-, et al.
(författare)
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The relation between mitral annulus motion and ejection fraction : a nonlinear function.
- 2000
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Ingår i: Journal of the American Society of Echocardiography. - : Elsevier BV. - 0894-7317 .- 1097-6795. ; 13:10, s. 896-901
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Tidskriftsartikel (refereegranskat)abstract
- In previous studies of the relation between mitral annulus motion (MAM) and left ventricular ejection fraction (EF), a linear relationship has been suggested. In this meta-analysis of 434 patients, we show that the relation is nonlinear and that a linear regression model overestimates EF in the lower range of MAM. The relation is better described by an S function and is influenced by age and heart size.
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| 18. |
- Emilsson, Kent, 1963-, et al.
(författare)
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The relation between mitral annulus motion and ejection fraction changes with age and heart size.
- 2000
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Ingår i: Clinical Physiology. - : John Wiley & Sons. - 0144-5979 .- 1365-2281. ; 20:1, s. 38-43
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Tidskriftsartikel (refereegranskat)abstract
- Mitral annulus motion (MAM) has recently been introduced as an index of left ventricular function. Several echocardiographic studies have shown good agreement between ejection fraction (EF) and MAM x 5, where MAM is the total mitral annulus motion, measured in mm, and EF is expressed as a percentage. This means that if MAM is used for estimation of left ventricular function, the conversion factor 5 is used, if the function is expressed as EF. In these studies, the mean age of the patients was over 60 years. The present study, including 102 patients, shows that in patients aged 20-40 years, the conversion factor is about 4.3, in patients aged 41-60 years it is about 4.6 and in patients aged 61-80 years it is about 5.0. It was also found that the ratio EF/MAM decreases with increasing height and left ventricular diameter, both variables closely connected to heart size. The results suggest that when MAM is used in assessment of left ventricular function, it is unwise to express the function in terms of EF. It is preferable to use MAM as a direct index of ventricular function, using reference values referred to aged and height. If the estimated function is expressed in terms of EF, different converting factors must be used depending on the age of the patients.
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| 19. |
- Emilsson, Kent, 1963-, et al.
(författare)
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The relation between mitral annulus motion and left ventricular ejection fraction in atrial fibrillation.
- 2000
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Ingår i: Clinical Physiology. - : Wiley. - 0144-5979 .- 1365-2281. ; 20:1, s. 44-9
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Tidskriftsartikel (refereegranskat)abstract
- Mitral annulus motion (MAM) has recently been introduced as an index of left ventricular function. Previous studies have shown a good agreement between MAM (mm) x 5 and ejection fraction in middle-aged and elderly patients. These studies only included patients with sinus rhythm, while patients with atrial fibrillation were excluded. In the present study, MAM was reduced in patients with atrial fibrillation while ejection fraction (EF) did not differ from age-matched control patients with sinus rhythm. The 'conversion factor' (EF/MAM) was 7.2 in the group with atrial fibrillation and 5. 1 in controls with sinus rhythm. This difference must be taken into account when MAM is used to estimate left ventricular function in patients with atrial fibrillation. Patients with atrial fibrillation had lower stroke volume and higher heart rate than patients with sinus rhythm. A decreased systolic long-axis shortening was found (P<0.005) compared to patients with sinus rhythm, but no difference in short-axis diameter shortening.
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| 20. |
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| 21. |
- Jorstig, Stina, 1978-, et al.
(författare)
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Distance and area measurement of the right atrium and ventricle by echocardiography and cardiac magnetic resonance imaging : do we measure the same thing?
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: It has previously been shown that stroke volumes measured by transthoracic echocardiography (TTE) are underestimated, compared to cardiac magnetic resonance (CMR) imaging. The purpose of this study was to evaluate differences in distance and area measurements of the right atrium (RA) and the right ventricle (RV) by TTE and CMR.Methods: TTE examinations and CMR examinations were subsequently performed in 12 healthy volunteers. Three distances (RAL - right atrial length, RVIT3 - right ventricular inflow tract, RVLAX - right ventricular long axis) and one area (RVA - right ventricular area) were measured in TTE and CMR. Stroke volumes were also calculated using conventional methods available on each modality. Both intramodality and intermodality comparisons were performed based on measurements from three observers. One of the observers performed measurements in both TTE and CMR.Results: Intermodality comparisons showed that all distance and area measurements were significantly smaller using TTE (Table 1). Two of the measurements, RVIT3 and RVA, differed at about 50%. Calculated stroke volumes showed, consistent with previous results, that the TTE stroke volumes are substantially underestimated compared to CMR volumes. Intramodality variations of distance and area measurements were considerably smaller (Table 1).Conclusions: Our results show that RV distances and areas measured by TTE are smaller compared to CMR, probably due to differences in defining the endocardial borders. These differences subsequently result in smaller stroke volumes when using TTE. Caution should be taken when comparing distances, areas and volumes measured by TTE and CMR.
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| 22. |
- Jorstig, Stina Hellstrand, 1978-, et al.
(författare)
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A study to determine the contribution to right ventricle stroke volume from pulmonary and tricuspid valve displacement volumes
- 2015
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 35:4, s. 283-290
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Describing the systolic function of the right ventricle (RV) is a difficult task due to the complex shape and orientation of the RV. The purpose of this study was to investigate the extent to which the volumes encompassed by the pulmonary and tricuspid valve displacements contribute to the total right ventricle stroke volume (RVSV).METHODS: Twelve healthy volunteers were examined using cardiac magnetic resonance (CMR). Two series of time-resolved axially rotated MR images were acquired that encompassed the tricuspid valve and the pulmonary valve, respectively. The volume related to each valve movement, the tricuspid plane displacement (TPD) and the pulmonary plane displacement (PPD), was determined by delineation in diastole and systole. These volumes, RVSVTPD and RVSVPPD , were compared to the stroke volume to determine the contributions to the total stroke volume from the TPD and the PPD. The remaining volume of the total RVSV was referred to as RVSVOther . An initial in vitro study was carried out to validate the accuracy of volume measurements using axially rotated images.RESULTS: In vitro measurements indicated that the method for volumetric measurements using axially rotated images was a very accurate one, with a mean difference of 0·04 ± 0·10 ml. The in vivo measurements of RVSVTPD , RVSVPPD and RVSVOther were 45 ± 10%, 13 ± 2% and 42 ± 11%, respectively.CONCLUSIONS: Right ventricle stroke volume is determined by different individual volume changes as follows: RVSVTPD together with RVSVOther contributes to almost the entire RVSV in nearly equal proportions, while RVSVPPD contributes only a small amount and is approximately 30% of either RVSVTPD or RVSVOther.
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| 23. |
- Jorstig, Stina Hellstrandh, 1978-, et al.
(författare)
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Calculation of right ventricular stroke volume in short-axis MR images using the equation of the tricuspid plane
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - Malden, USA : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 32:1, s. 5-11
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Tidskriftsartikel (refereegranskat)abstract
- Short-axis (SA) magnetic resonance (MR) images are commonly planned parallel to the left atrioventricular valve. This orientation leads to oblique slices of the right ventricle (RV) with subsequent difficulties in separating the RV from the right atrium in the SA images. The insertion points of the tricuspid valve (TV) in the myocardium can be clearly identified in the right ventricle long axis (RVLA) and four-chamber (4CH) views. The purpose of this study was to develop a method that transfers the position of the tricuspid plane, as seen in the RVLA and 4CH views, to the SA images to facilitate the separation of the RV from the atrium. This methodology, termed Dissociating the Right Atrium from the Ventricle Volume (DRAW), was applied in 20 patients for calculations of right ventricular stroke volume (RVSV). The RVSV using DRAW (RVSVDRAW) was compared to left ventricular stroke volumes (LVSV) obtained from flow measurements in the ascending aorta. The RVSV was also determined using the conventional method (RVSVCONV) where the stack of images from the SA views are summarized, and a visual decision is made of the most basal slice to be included in the RV. The mean difference between RVSVDRAW and LVSV was 0.1 +/- 12.7 ml, while the mean difference between RVSVCONV and LVSV was 0.33 +/- 14.3 ml. Both the intra- and interobserver variability were small using the DRAW methodology, 0.6 +/- 3.5 and 1.7 +/- 2.7 ml, respectively. In conclusion, the DRAW method can be used to facilitate the separation of the RV and the atrium.
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| 24. |
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| 25. |
- Kumar, Sanjay, et al.
(författare)
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Diastolic function improves after resolution of takotsubo cardiomyopathy
- 2016
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 6:1, s. 17-24
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Takotsubo cardiomyopathy (TTC) is a condition of reversible left ventricular (LV) systolic dysfunction. However, the diastolic function (DF) manifestations of TTC have not been widely investigated. We performed a bicentric study with retrospective analysis of DF in patients with TTC, during onset and at follow-up.METHODS: Twenty-eight patients with TTC (64 ± 10 years, F 24) were included. All underwent echocardiograms acutely and at the recovery phase (average three months later). Diastolic and systolic function parameters were recorded, including E-wave velocity (E), A-wave velocity, E/A ratio, relaxation (e') and contractility (S') based on tissue Doppler velocities of the mitral annuli, ejection fraction (EF), left atrial (LA) size and DF stages.RESULTS: Recovery, including the mean difference with 95% confidence interval, was associated with tending improvement (i.e. uncorrected significance) in E [13 cm s(-1) (-24, -2·3), P = 0·02] and in E/A ratio [0·2 (-0·41, -0·02), P = 0·04], as well as significant improvement (after multiple comparison correction) in mean e' [2·0 cm s(-1) (-3·3, -1·2), P<0·001] and in A-wave duration [29 ms (-46·7, -12·7), P = 0·002]. LA area tended to decrease during recovery [-2 cm² (0·33, 2·4), P = 0·01]. Improvement in DF stages was significant between the phases (21% versus 58% defined as normal DF, P = 0·016). Improvement in LVEF correlated with improvement in mean e' (r = 0·52, P = 0·02).CONCLUSIONS: TTC is associated with an acute impairment of conventional DF variables, which improves during recovery. DF recovery seems to occur in parallel with systolic recovery in patients with TTC.
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| 26. |
- Kähäri, Anders, et al.
(författare)
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Assessment of left ventricular function from M-mode measurement of circumflex artery motion recorded by coronary angiography.
- 2003
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa Healthcare. - 1401-7431 .- 1651-2006. ; 37:5, s. 259-265
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the usefulness of M-mode measurement of circumflex artery motion (CAM) for assessment of left ventricular (LV) function.DESIGN: Seventy-two patients referred for coronary angiography and LV angiography were included. Ejection fraction (EF) was calculated from LV angiography and systolic and diastolic parameters of CAM were measured by M-mode from coronary angiography. Twenty-three patients, examined by echocardiography of mitral annulus motion (MAM) within 24 h before the angiographic examination, formed a subgroup for comparison between angiographic M-mode of CAM and echocardiographic M-mode of MAM.RESULTS: In addition to previous reported CAM amplitude and longitudinal fractional shortening (FSL) the maximal systolic velocity of CAM can be reliably recorded by M-mode. The diastolic indices, atrial contribution to the total amplitude and maximal early and late diastolic velocities, are also well monitored by M-mode of CAM in comparison with echocardiographic MAM.CONCLUSION: LV systolic and diastolic function can be assessed by M-mode of CAM.
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| 27. |
- Kähäri, Anders, et al.
(författare)
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Circumflex artery motion : a new angiographic method for assessment of left ventricular function
- 2003
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Ingår i: Scandinavian Cardiovascular Journal. - Oslo, Norway : Taylor & Francis. - 1401-7431 .- 1651-2006. ; 37:2, s. 80-86
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the usefulness of circumflex artery motion (CAM) for assessment of left ventricular (LV) function.DESIGN: Seventy-three consecutive patients referred for coronary angiography and LV angiography were included. Ejection fraction (EF) was calculated from LV angiography and CAM was measured from coronary angiography.RESULTS: The ratio between CAM and the end-diastolic length of the ventricle, which can be denominated long-axis fractional shortening (FS(L)), was found to be a better index of LV function than CAM per se. There was a significant linear correlation between EF and FS(L) (r = 0.81, SEE = 8.2, p < 0.001). When values of FS(L) > or =10% were selected to define a normal EF (> or =50%) there was a sensitivity of 95% and a specificity of 93%. Visual estimation of EF from CAM was not as good as the use of calculated FS(L) but may me useful as a fast screening method.CONCLUSION: LV systolic function can be assessed by studying CAM recorded by coronary angiography.
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| 28. |
- Loiske, Karin, 1978-, et al.
(författare)
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A comparison of right ventricular volume change during systole obtained using the monoplane Simpson's method in two-dimensional echocardiographic apical four-chamber view with right ventricular volume change obtained using a prisma model reflecting the systolic long-axis shortening of the right ventricle of the heart : a pilot study
- 2008
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Ingår i: Experimental and clinical cardiology. - Oakville, Ont. : Pulsus Group. - 1205-6626. ; 13:2, s. 75-78
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Forskningsöversikt (refereegranskat)abstract
- The right ventricle of the heart has a complex geometry, making it difficult to measure its function and volume. In the present study, right ventricular (RV) volume change during systole in two-dimensional echocardiographic apical four-chamber view was estimated using the monoplane Simpson's method. Measurements of volume change using the monoplane Simpson's method were compared with those obtained using a theoretical prisma model, which is believed to reflect RV systolic long-axis shortening. The mean volume change during systole obtained using the theoretical prisma model (10.2+/-3.2 mL) was significantly (P<0.001) smaller than that obtained using the monoplane Simpson's method (20.7+/-7.1 mL). This difference was probably due to the patient group studied, which had a mean (+/- SD) age of 58.6+/-14.1 years. In elderly individuals, systolic shortening in the short-axis direction has a greater impact on volume change during the heart cycle more than in younger individuals. However, not even the volume change during systole obtained using the monoplane Simpson's method in echocardiographic four-chamber view was able to determine the 'real' RV stroke volume. Thus, the volume change during systole in other echocardiographic views needs to be considered as well.
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| 29. |
- Loiske, Karin, 1978-, et al.
(författare)
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Echocardiographic measurements of the right ventricle : right ventricular outflow tract 1
- 2010
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Ingår i: Clinical research in cardiology. - Berlin : Springer. - 1861-0684 .- 1861-0692. ; 99:7, s. 429-435
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Tidskriftsartikel (refereegranskat)abstract
- The size of the ventricles of the heart is important to establish during the clinical echocardiographic examination. Due to the complex anatomy of the right ventricle, it is difficult to measure its size at times. One of the most frequently used ways is to measure the right ventricular outflow tract (RVOT1), probably due to its good reproducibility. However, in the literature different ways are described to measure RVOT1, both at different sites and using different methods such as M-mode and 2D. The first aim of the present study was to exam if there is a significant difference in the outcome of RVOT1 using different sites and methods to measure it. The second aim was to study if there is a significant difference between the usually preferred left lateral decubitus position during the echocardiographic examination and the supine decubitus position, which the echocardiographer sometimes can be compelled to use if the patient is unable to lie in the left lateral decubitus position
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| 30. |
- Loiske, Karin, 1978-, et al.
(författare)
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Left and right ventricular systolic long-axis function and diastolic function in patients with takotsubo cardiomyopathy
- 2011
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Ingår i: Clinical Physiology and Functional Imaging. - Oxford : Wiley. - 1475-0961 .- 1475-097X. ; 31:3, s. 203-208
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Takotsubo cardiomyopathy is characterized by apical wall motion abnormalities without coronary stenosis. Limited information is available on the genesis of the underlying reversible contractile disorder. Our objective in this prospective study was to investigate biventricular changes in systolic long-axis function and diastolic parameters in the acute phase and after recovery.Methods and results: Thirteen consecutive patients were examined by echocardiography and coronary angiography at admission and again by echocardiography after 3 months. Amplitudes, systolic and diastolic velocities of the mitral and tricuspid annuli and conventional diastolic parameters were measured. Systolic long-axis shortening of the left ventricle (LV) and right ventricle (RV) improved from 9·6 ± 2·2 mm to 11·2 ± 1·9 mm (P = 0·02) and from 21·3 ± 3·6 mm to 24·1 ± 2·8 mm (P = 0·02), respectively. LV systolic, early and late diastolic velocities measured by pulsed-wave tissue Doppler also improved, while additional conventional diastolic parameters of the LV and RV diastolic function were unchanged.Conclusions: Takotsubo cardiomyopathy temporarily affects systolic LV and RV function, while most diastolic parameters remain unchanged
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| 31. |
- Nygren, Britt-Marie, 1956-, et al.
(författare)
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Comparison between aortic valve area obtained by planimetry and by using the continuity equation : a transthoracic echocardiographic study
- 2014
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Ingår i: Experimental and Clinical Cardiology. - : Cardiology Academic Press. - 1918-1515. ; 20:1, s. 2665-2673
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: In patients with aortic stenosis the valve area is usually obtained by transthoracic echocardiography (TTE) and the continuity equation. The method is time consuming and another way to obtain the area is to trace the valves (planimetry).In the present study the both methods are compared.Methods: 34 consecutive patients with known aortic stenosis were included and examined by TTE. The aortic valve area was obtained using planimetry in the short axis view and by using the continuity equation.Results: There was no significant difference between the two methods (p=0.16) and the correlation was rather good (r=0.60; p<0.01). The agreement was better in the lower ranges of areas (<1.1 cm2) than in the higher ranges (>1.1 cm2).Conclusions: The agreement between the both methods is rather good in the lower ranges of areas (<1.1 cm2), but worse in the higher ranges of areas (>1.1 cm2). The difference between the areas in the lower ranges can be up to 0.3 cm2, a difference that can be the difference between thoracic surgery or not. It is therefore best to still use the continuity equation during TTE.
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| 32. |
- Nygren, Britt-Marie, 1956-, et al.
(författare)
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The Aortic, Mitral and Tricuspid Annuli and Their Velocities : A Comparative Echocardiographic Study
- 2014
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Ingår i: Journal of Clinical & Experimental Cardiology. - : OMICS Publishing Group. - 2155-9880 .- 2155-9880. ; 5:8
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The velocities at the mitral (MA) and tricuspid (TA) annuli have earlier been studied by using both colour coded tissue Doppler imaging (TVI) and pulsed wave tissue Doppler imaging (PW DTI) but the velocities at the aortic annulus (AA) and the both other annuli have only been examined using TVI and not PW DTI in one study before. Therefore the aim of the present study was to compare the systolic (s´)-, early (e´)- and late (a´) diastolic velocities at the three different annuli with both methods.Design: 24 healthy subjects were examined by echocardiography and the velocities at the annuli were measured using PW DTI and TVI.Results: For all the velocities there was a statistically significant difference (p<0.001) between the two methods, the velocities obtained by PW DTI being higher. However some heterogeneity of the mean velocity differences between methods were noted by annuli and site, but PW DTI always showing highest mean levels. There were also statistically significant velocity differences between different sites and annuli. There was a good-very good intra- and inter observer reproducibility of measuring the velocities at the aortic annulus.Conclusion: The velocities were significantly higher using PW DTI than using TVI at the different annuli, probably mainly due to the way the respective method is measuring the velocities. In addition there was shown some heterogeneity of the mean velocity differences and statistically significant velocity differences between different sites and annuli.The both methods need different reference values and could not be used interchangeably. The findings could be of importance in special cases where the interaction between the three different annuli and sites is of importance, but including the velocities at all the three different sites in a clinical routine echocardiographic examination will often not be necessary.
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| 33. |
- Sundström, Daniel, et al.
(författare)
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Acute effects on the ventricular function in Swedish snuffers : an echocardiographic study
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - Hoboken, USA : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 32:2, s. 106-113
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Cigarettes and Swedish snuff contain nicotine, which influence the cardiovascular system. Cigarette smoke has been shown to give an acute impairment in diastolic heart parameters. The systolic and diastolic heart function in snuff users is not thoroughly enough investigated. The aim of this study was to investigate if Swedish snuff will give an acute decrease in systolic and diastolic heart parameters in the left and right ventricles in healthy Swedish snuffers.Methods and results: Thirty healthy volunteers were examined with echocardiography. The study involved recordings from four different times: before snuff intake, 5 and 30 min after intake and finally 30 min after snuff withdrawal. The systolic and diastolic heart parameters were collected with conventional echocardiographic methods. In addition, the heart frequency and blood pressure response were measured. The pulse and blood pressure response were significantly altered (P<0Æ01) during the test. Left ventricular ejection fraction and the amplitudes of mitral and tricuspid annulus motion did not alter significantly. The main finding in the study was the significant decrease (P<0Æ05) in several diastolic heart parameters for both the left and right ventricles.Conclusions: This study shows that snuff intake causes a significant decrease in E ⁄ A ratio and a delay in ventricular relaxation and therefore a decrease in diastolic heart function in the left and right ventricles. The mechanism behind these alterations is probably very complex, but a combination of nicotine effects and loading conditions is probably the main factor.
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| 34. |
- Sundström, Daniel, et al.
(författare)
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Chronic nicotine effects on left ventricular function in healthy middle-aged people : an echocardiographic study
- 2013
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Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 33:4, s. 317-324
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Tidskriftsartikel (refereegranskat)abstract
- AimsCigarettes and Swedish snuff influence the cardiovascular system in many ways. Cigarette and snuff usage have been linked with an acute impairment in several diastolic cardiac parameters during intake. The aim of this study is to investigate whether long-term usage of Swedish snuff or cigarettes also causes a more permanent impairment of systolic and/or diastolic cardiac parameters in the left ventricle in otherwise healthy middle-aged snuffers and smokers.Methods and resultsEighty-seven age-matched volunteers were included and examined with echocardiography. The volunteers were divided into three subgroups; one group with non-tobacco users, one group with long-term smokers and finally one group with long-term snuffers. The smokers and snuffers were instructed not to use these products for at least 5h before the examination. The systolic and diastolic cardiac parameters were collected at one time. Most of the systolic parameters measured were unaltered between the tobacco subgroups and non-tobacco users, and therefore, no alteration of significance was found in systolic parameters. Also, almost all of the diastolic parameters measured were not significantly impaired in the tobacco subgroups compared with non-tobacco users. However, the deceleration time (DT) was slightly prolonged (P<0 center dot 05) and thus statistically significant in the tobacco subgroups. This finding is somewhat difficult to interpret but may be seen as random.ConclusionsThis study reveals that most systolic- and diastolic cardiac parameters are not chronically significantly altered in middle-aged long-term tobacco users compared with age-matched non-tobacco users.
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| 35. |
- Thunberg, Per, 1968-, et al.
(författare)
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Estimation of ejection fraction and stroke volume using single- and biplane magnetic resonance imaging of the left cardiac ventricle
- 2008
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Ingår i: Acta Radiologica. - London : Taylor & Francis. - 0284-1851 .- 1600-0455. ; 49:9, s. 1016-1023
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: In cardiac magnetic resonance imaging (MRI), left ventricular stroke volume (SV) and ejection fractions (EF) are occasionally calculated using single-plane and biplane ellipsoid models. In previous studies, the calculated SV and EF using single- and biplane ellipsoid models have been compared to reference values calculated from short-axis (SA) images. In these studies, however, it has been emphasized that through-plane motion of the basal SA images represents an important source of error, which may result in incorrect reference values.Purpose: To compare the calculated SV and EF using single-plane and biplane ellipsoid models with SV and EF calculated from SA images in which compensation was made for through-plane motion.Material and Methods: A group of 20 patients who underwent MRI examination were included in the study. SV and EF were calculated using the stack of SA images (which had been compensated for through-plane motion) and compared to the SV and EF calculated according to the single- and biplane ellipsoid models.Results: The mean difference between the single-plane model and the reference was -0.3±6.5 for EF and 7.2±17.1 ml for SV. Corresponding comparison between the biplane method and the reference resulted in a mean difference of 0.3±6.1 for EF and 11.8±14.9 ml for SV.Conclusion: The results from this study show that left ventricular EF can be adequately estimated using the single- and biplane ellipsoid models, while SV tends to be overestimated using both geometrical models
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| 36. |
- Thunberg, Per, 1968-, et al.
(författare)
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Flow and peak velocity measurements in patients with aortic valve stenosis using phase contrast MR accelerated with k-t BLAST
- 2012
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Ingår i: European Journal of Radiology. - Clare, Ireland : Elsevier. - 0720-048X .- 1872-7727. ; 81:9, s. 2203-2207
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the accuracy of velocity measurements in patients with aortic valve stenosis using phase contrast (PC) imaging accelerated with SENSE (Sensitivity Encoding) and k-t BLAST (Broad-use Linear Acquisition Speed-up Technique).Methods: Accelerated quantitative breath hold PC measurements, using SENSE and k-t BLAST, were performed in twelve patients whose aortic valve stenosis had been initially diagnosed using echocardiography. Stroke volume (SV) and peak velocity measurements were performed on each subject in three adjacent slices using both accelerating methods.Results: The peak velocities measured with PC MRI using SENSE were -8.0±9.5% lower (p<0.01) compared to the peak velocities measured with k-t BLAST and the correlation was r=0.83. The stroke volumes when using SENSE were slightly higher 0.4±17.1 ml compared to the SV obtained using k-t BLAST but the difference was not significant (p>0.05).Conclusions In this study higher peak velocities were measured in patients with aortic stenosis when combining k-t BLAST with PC MRI compared to PC MRI using SENSE. A probable explanation of this difference is the higher temporal resolution achieved in the k-t BLAST measurement. There was, however, no significant difference between calculated SV based on PC MRI using SENSE and k-t BLAST, respectively.
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| 37. |
- Thunberg, Per, 1968-, et al.
(författare)
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Separating the left cardiac ventricle from the atrium in short axis MR images using the equation of the atrioventricular plane
- 2008
-
Ingår i: Clinical Physiology and Functional Imaging. - Oxford : Wiley-Blackwell Publishing Inc.. - 1475-0961 .- 1475-097X. ; 28:4, s. 222-228
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Tidskriftsartikel (refereegranskat)abstract
- Short axis (SA) images obtained from cardiac magnetic resonance imaging are used to advantage in the calculation of important clinical parameters such as the ejection fraction and stroke volume (SV). A prerequisite for these calculations is the separation of the left ventricle and the left atrium. When only using the information seen in the SA images this separation can be a source of error due to the through-plane motion of the basal part of the left ventricle. In this study a method is proposed where the separation of the left ventricle and the atrium is performed by identifying the intersections of the atrioventricular plane in the SA images. The equation of the atrioventricular plane was determined in both systole and diastole using long axis and four chamber image views. Stroke volumes were measured in 20 patients using SA images where the endocardium had been delineated. The SV obtained using the new method was compared with quantitative flow measurements and the conventional technique for calculation of SV from SA images, respectively. The agreement of SV was, according to Bland-Altman analysis, 2.0 ml (95% CI -12.0 to 15.9 ml) in comparison with the flow measurements and 2.2 ml (95% CI -9.2 to 13.6 ml) compared to the conventional method. Inter- and intra-observer variability, when using the new proposed method, was small. This study shows that the identification of the left atrioventricular plane in SA images can be used in the separation of the left atrium and ventricle.
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| 38. |
- Waldenborg, Micael, 1981-, et al.
(författare)
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Effect on left ventricular mass and geometry in patients with takotsubo cardiomyopathy
- 2015
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 49:1, s. 27-38
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Takotsubo cardiomyopathy (TTC) is a condition of transient left ventricular (LV) dysfunction. The effects on LV mass (LVM) and geometry have not been studied enough in TTC. Retrospectively, we analyzed our TTC cohort both by transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI), for comparative purposes.Design: Thirteen women undergoing TTE and MRI, at onset and three months later, were included. LVM was estimated by MRI, and two TTE-methods. Segmental wall thickness (SWT) was measured, whilst radial strain was assessed by TTE. Data analysis included Wilcoxon's test (between phases), Mann Whitney U- and McNemar's tests (between and within groups). Bland-Altman analyzes were used for intertechnique coherence, whilst interactions regarding TTE were tested using Spearman's coefficient.Results: LVM decreased during recovery (p<0.05), by MRI and one of the TTE-methods; truncated ellipsoid formula (TEF), which also showed relatively better coherence compared to MRI. SWT decreased in two of three sites, by both modalities, but with ambiguous coherence therebetween. The TEF-data interacted partially with a demonstrated increase in radial strain.Conclusions: TTC associates with acute increase in LVM, which appears to be an apical effect, tending to follow the changes in concentric wall motion. MRI and TTE show adequate coherence; primarily for the TEF-method regarding LVM.
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| 39. |
- Waldenborg, Micael, 1981-, et al.
(författare)
-
Effect on left ventricular mass and geometry in patients with takotsubo cardiomyopathy
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Aims: Takotsubo cardiomyopathy (TTC) is a condition of reversible left ventricular (LV) dysfunction. The effects, from acute to recovery phase, on LV mass (LVM) and the LV geometry are not thoroughly enough studied at TTC, which were the main aims of the present study. Retrospectively, we analyzed our cohort of TTC-patients, both with transthoracic echocardiography (TTE) and magnetic resonance imaging (MRI), to further investigate these changes, including intertechnique comparison.Methods: We studied 13 female TTC-patients, undergoing TTE and MRI acutely, and three months later at follow-up. LVM was measured with MRI- and five different TTE-methods. Segmental wall thickness (SWT) was assessed, and used for LV hypertrophy (LVH) geometry categorization. Radial strain was measured at TTE. Data analysis included Wilcoxon signed-test (between phases), Mann Whitney U- and McNemar’s tests (between and within groups). Spearman’s coefficient was used for intertechnique coherence (with BlandAltman plots) and for correlations of simultaneous TTE changes.Results: LVM decreased significantly between phases (p<0.05), by MRI and with two TTE-methods. Two of three SWT-sites became significantly thinner, with adequate correlation (rs≥0.69) between techniques, while LVH categories remained unchanged. Relatively better consistency, compared with MRI, was shown for one of the TTE-methods used to estimate LVM (truncated ellipsoid (TE)). Radial strain improved significantly, with partial correlation towards the TE-method.Conclusions: TTC associates with acute increase in LVM, which seems to be a local effect, tending to occur in parallel with changes in concentric wall motion. MRI and TTE shows adequate consistency, primarily for the TE-method regarding LVM.
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| 40. |
- Waldenborg, Micael, 1981-, et al.
(författare)
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Multidisciplinary assessment of takotsubo cardiomyopathy : a prospective case study
- 2011
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261 .- 1471-2261. ; 11, s. 14-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The cause of tako tsubo cardiomyopathy remains unclear. We used a multidisciplinary approach to investigate if a common pathophysiological denominator could be outlined.Methods: Within 3 days following symptom presentation and again after 3 months we investigated all patients coming to our institution and diagnosed with tako-tsubo cardiomyopathy. Patients underwent extensive biochemical screening. Left ventricular function was evaluated by echocardiography and contrast-enhanced cardiac magnetic resonance imaging. Cardiac autonomic function was studied by heart rate variability and signal-averaged electrocardiogram and posttraumatic stress and depression were investigated by questionnaires (the Posttraumatic Stress Syndrome 10-Questions Inventory, PTSS-10 and the Montgomery-Asberg depression rating scale, self rated version, MADRS-S).Results: During 2 years, 13 consecutive patients were included. Markers of myocardial damage and heart failure were slightly to moderately elevated and ejection fraction (echocardiography and MRi) was moderately reduced at hospitalization and improved to normal values in all patients. Signal averaged ECG demonstrated a statistically significant shorter duration of the filtered QRS complex in the acute phase as compared to follow-up. In heart rate variability analysis, SDNN and SDANN were shorter acutely compared to follow-up. Two patients fulfilled criteria for posttraumatic stress syndrome while 7 patients were in the borderline zone. There was a statistically significant inverse correlation between PTSS-10 score and QRS duration in the signal-averaged ECG (r = -0.66, P = 0.01).Conclusions: Patients with tako tsubo cardiomyopathy have altered cardiac autonomic function and a high incidence rate of borderline or definite posttraumatic stress syndrome acutely. This is in line with findings in patients with myocardial infarction and does not allow conclusions on cause and effect.
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