| 1. |
- Fraser, AG, et al.
(författare)
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Feasibility and reproducibility of off-line tissue Doppler measurement of regional myocardial function during dobutamine stress echocardiography
- 2003
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Ingår i: European Journal of Echocardiography. - 1525-2167 .- 1532-2114. ; 4:1, s. 43-53
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Off-line post-processing of colour tissue Doppler from digital loops may allow objective quantification of dobutamine stress echocardiography. We assessed the reproducibility of off-line measurements of regional myocardial velocities. Methods and Results: Nine observers analysed 10 studies, each making 2400 observations. Coefficients of variation in basal segments from apical windows, at rest and maximal stress, were 9-14% and 11-18% for peak systolic velocity, 16-18% and 17-19% for time-to-peak systolic velocity, 9-17% and 18-24% for systolic velocity time integral, and 18-23% and 21-27% for systolic acceleration. Coefficients of variation for diastolic velocities in basal segments at rest were 11-40%. Coefficients of variation for peak systolic velocity were 10-24% at rest and 14-28% at peak in mid segments, and 19-53% and 29-69% in apical segments. From parasternal windows coefficients of variation for peak systolic velocity were 14-16% in basal posterior, and 19-29% in mid-anterior segments. High variability makes measurement unreliable in apical and basal anterior septal segments. The feasibility of obtaining traces was tested in 92 subjects, and >90% in all basal and mid segments apart from the anterior septum. Conclusion: Quantification of myocardial functional reserve by off-line analysis of colour tissue Doppler acquired during dobutamine stress is feasible and reproducible in 11 segments of the left ventricle. The most reliable measurements are systolic velocities of longitudinal motion in basal segments.
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| 2. |
- Gunnes, S., et al.
(författare)
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Analysis of the effect of temporal filtering in myocardial tissue velocity imaging
- 2004
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Ingår i: Journal of the American Society of Echocardiography. - : Mosby Inc. - 0894-7317 .- 1097-6795. ; 17:11, s. 1138-1145
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Tidskriftsartikel (refereegranskat)abstract
- Signal filtering to reduce random noise may compromise the reliability of tissue velocity measurements. This study evaluates the influence of temporal filters on time and velocity variables derived from myocardial tissue velocity images acquired in 15 healthy individuals at a high frame rate (142-184 Hz). Different time and velocity variables from the basal septum were analyzed offline before and after temporal filtering from 20 to 60 milliseconds in 10-millisecond steps using software enabling retrieval of myocardial Doppler velocity and 2-dimensional information from different cardiac locations during the same cardiac cycle. Filtering affected the results by increasing variability of time and by underestimation of velocity variables, the rapid isovolumic events being particularly filter sensitive. In addition, at a certain range of sampling rate, ambiguity of filtering effect was observed. This ought to be considered if an optimal, high-fidelity tissue Doppler velocity signal is to be obtained.
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| 3. |
- Hayashi, Shirley Yumi, et al.
(författare)
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Improvement of cardiac function after haemodialysis : Quantitative evaluation by colour tissue velocity imaging
- 2004
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 19:6, s. 1497-1506
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Tidskriftsartikel (refereegranskat)abstract
- Background. Overhydration and accumulation of uraemic toxins may influence the myocardial function in haemodialysis (HD) patients. To evaluate cardiac function and the effects of fluid and solute removal during a single session of HD, colour tissue velocity imaging (TVI) was used. This new technique, which is less load dependent than conventional echocardiography, allows an objective quantitative assessment of myocardial contractility, contraction and relaxation. Methods. Conventional echocardiographic and TVI images were recorded before and after a single HD session in 13 clinically stable HD patients (62 +/- 10 years, six males) and in 13 sex- and age-matched healthy controls. Myocardial tissue velocities (v; cm/s) for isovolumetric contraction (IVC), peak systole (PS), early (E) and late (A') diastolic filling and strain rate (SR) were measured. Results. Left ventricular hypertrophy (LVH) was present in 12 patients. TVI gave additional information in comparison with conventional echocardiography. Before HD, PS (5.0 +/- 0.8 vs 6.0 +/- 1.2 cm/s, P < 0.05), E' (5.7 +/- 1.7 vs 7.3 +/- 2.0 cm/s, P < 0.05) and A' (6.6 +/- 1.7 vs. 8.3 +/- 2.9 cm/s, P < 0.05) velocities were lower in the patients than in the controls, indicating systolic and diastolic dysfunction. The HD session increased IVCv (4.0 +/- 1.7 to 5.5 +/- 1.9 cm/s; P < 0.001), PSv (5.0 +/- 0.8 to 5.7 +/- 0.8 cm/s; P < 0.05) and SR (0.7 +/- 0.2 to 0.9 +/- 0.2 1/s; P < 0.05) and decreased E/E' (16.7 +/- 7.7 to 12.2 +/- 4.0, P < 0.05), indicating improved systolic function and decreased LV filling pressure, respectively. Linear regression analysis demonstrated a dependency of systolic contraction (PSv) and contractility (IVCv) upon plasma levels of phosphate (r(2) = 0.70, P < 0.005, r(2) = 0.33, P < 0.01). Conclusions. Using TVI, HD patients demonstrate myocardial dysfunction, which is found less frequently when using conventional echocardiography. The systolic function seems to be impaired by high plasma levels of phosphate and an increased Ca x P product. One single session of HD improved systolic function as indicated by increases in IVCv, PSv and SR. Further studies are needed to clarify if this effect of HD is due to the acute removal of fluid, the removal of solutes or both.
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| 4. |
- Jensen, J., et al.
(författare)
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Deterioration in peak systolic velocity is closely related to ischaemia during angioplasty : a vectorcardiographic and tissue Doppler imaging study
- 2001
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Ingår i: Clinical Science. - : Portland Press Ltd.. - 0143-5221 .- 1470-8736. ; 100:2, s. 137-143
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Tidskriftsartikel (refereegranskat)abstract
- We tested the hypothesis that the extent of signs of ischaemia detected by vectorcardiography (VCG) during elective coronary angioplasty (percutaneous transluminal coronary angioplasty: PTCA) is related to systolic and diastolic myocardial velocities, as determined by tissue Doppler echocardiography. A total of 15 patients undergoing PTCA (12 men/three women; age 61 +/- 9 years), without prior myocardial infarction and with an election fraction of > 50%, were included. The balloon inflation was repeated three times, with minimum intervals of 2 min between inflations. Tissue Doppler echocardiography was performed. in an apical two- or four-chamber view, before and at the end of each inflation. Peak systolic velocity, time-to-peak systolic velocity (TTP), peak early (E-m) and late (A(m)) diastolic velocities, the E-m/A(m) ratio and jsovolumic relaxation time were measured in the basal segments of the left ventricle. VCG recordings were carried out during the whole procedure. ST vector magnitude (ST-VM) and ST change vector magnitude (STC-VM) were monitored. The total duration and area of each VCG change during inflation were calculated for each patient. Isovolumic relaxation time, peak E-m and A(m) values and the E-m/A(m) ratio did not change significantly during inflation. Peak systolic velocity decreased (6.7+/-2.0 to 5.3 +/- 1.9 cm/s; P < 0.001) and TTP increased (157 +/- 60 to 192 +/- 60 ms; P<0.01) during inflation. Both STC-VM rime (r = -0.68, P<0.01) and STC-VM area (r = -0.68, P < 0.01) were related to peak systolic velocity during inflation. STC-VM time was also related (r = 0.55, P < 0.05) to the difference in peak systolic velocity during compared with before inflation. ST-VM was less closely related to peak systolic velocity. Thus the duration and degree of ischaemia, as measured by VCG, are related to peak systolic velocity in the basal segments of the left ventricle.
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| 5. |
- Lind, Britta, et al.
(författare)
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Left ventricular isovolumic velocity and duration variables calculated from colour-coded myocardial velocity images in normal individuals
- 2004
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Ingår i: European Journal of Echocardiography. - : Oxford University Press (OUP). - 1525-2167 .- 1532-2114. ; 5:4, s. 284-293
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To describe the normal myocardial velocity profile during the isovolumic contraction and relaxation period at four different locations within left ventricular base and to establish normal age and gender related isovolumic time and velocity values. Methods and results: In 49 healthy individuals (26 women/23 men) in age groups 21-49 and 50-76 years, tissue velocity profiles and 2D-data were acquired at high temporal resolution (90-147 frames/s) for a subsequent off-line analysis using software enabling retrieval of myocardial Doppler velocity and 2D/anatomical M-mode information from different cardiac locations during the same cardiac cycle. The obtained velocity curves during the isovolumic contraction and relaxation period were usually biphasic and displayed clear regional differences in their respective positive and negative maximal velocities. Besides some gender related differences, mainly in the duration of the positive and negative velocity wave components during the isovolumic contraction period, a clear age-dependent increase in the duration of the isovolumic relaxation phase and its negative and positive velocity components was observed. Conclusion: Modern tissue Doppler imaging supplemented by anatomical M-mode images of the mitral and aortic valve movements allows a proper analysis of the rapid isovolumic myocardial movements. The presented normal isovolumic time and velocity values may prove useful for studies of myocardial function.
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| 6. |
- Quintana, M., et al.
(författare)
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Assessment of the longitudinal and circumferential left ventricular function at rest and during exercise in healthy elderly individuals by tissue-Doppler echocardiography : relationship with heart rate
- 2004
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Ingår i: Clinical Science. - : Portland Press Ltd.. - 0143-5221 .- 1470-8736. ; 106:5, s. 451-457
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Tidskriftsartikel (refereegranskat)abstract
- Tissue-Doppler echocardiography (TDE) has been introduced to quantify stress echocardiography by means of assessing the left ventricular (LV) segmental myocardial velocities and excursion. The interaction between LV long- and short-axis function during physical exercise has not been elucidated completely. The aim of the present study was to investigate long- and short-axis LV function, as assessed by myocardial velocities and excursions at rest and during exercise and its possible relationship with heart rate in healthy elderly individuals by TIDE Twenty-seven individuals underwent an exercise test in the supine position on a bicycle ergometer. The initial workload was 30 Watts, followed by 20-Watt increments every third minute. Standard echocardiographic images with super-imposed colour TDE were digitized at the end of each step. The following variables were studied in the LV long- and short-axis: myocardial peak systolic velocity (PSV) and excursion, isovolumic contraction and relaxation times, peak velocity at early diastole (E-wave) and peak velocity at late diastole (A'-wave) and the E'/A' ratio. Increments in myocardial peak systolic velocity and excursion in the LV long-axis were more pronounced during low workloads. The increase in those variables in the short-axis occurred mainly, at higher exercise loads. The improvement in LV long- and short-axis functions was closely related to the increase in the heart rate. Shortening of the isovolumic contraction and relaxation times occurred only at the initial stages of exercise. An increase in the long-axis E'/A' ratio occurred during exercise, whereas this ratio was unchanged in the short-axis. In conclusion, during exercise, the LV long- and short-axis functions behave differently, and increases in LV long- and short-axis functions are related to changes in heart rate. Therefore, in the interpretation of echocardiographic findings during exercise stress echocardiography, these facts have to be taken into account.
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| 7. |
- Quintana, M., et al.
(författare)
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Electromechanical coupling, uncoupling, and ventricular function in patients with bundle branch block : A tissue-doppler echocardiographic study
- 2004
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Ingår i: Echocardiography. - : Wiley. - 0742-2822 .- 1540-8175. ; 21:8, s. 687-698
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Tidskriftsartikel (refereegranskat)abstract
- Background: Left bundle branch block (LBBB) is associated with impaired left ventricular (LV) function and increased morbidity and mortality, especially in patients with structural heart diseases. The mechanisms are poorly understood. Subjects and Methods: Subjects with isolated LBBB (n = 20), right bundle branch block (RBBB, n = 20), and controls (C, n = 20) were studied with standard two-dimentional (2D), and color-encoded tissue-Doppler echocardiography (TDE). Inter- and intraventricular systolic and diastolic coordination were assessed from the TDE velocity profiles. LV function was assessed by 2D echocardiography, by TDE-derived peak systolic velocities, and the atrioventricular (AV) plane displacement. Results: Subjects with LBBB had longer electromechanical delays and longer isovolumic relaxation times than did the C and RBBB groups (P < 0.001). For the LBBB subjects compared with the RBBB and C groups, ejection times were shorter, peak systolic velocities and AV plane displacements were lower, they had larger LV end-systolic volumes and lower LV ejection fraction (all P < 0.001), and the atrial contribution to A-V plane displacement was higher (P < 0.01). There were no differences in diastolic or filling times among the groups. Conclusions: In patients with LBBB, delayed regional electromechanical coupling and uncoupling leads to generalized intra- and interventricular asynchrony, thereby explaining the depressed regional and global LV functions. Assessment of the electromechanical coupling and uncoupling processes and their consequences on cardiac function in patients with BBB and structural heart diseases may be possible using TDE.
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| 8. |
- Saha, S. K., et al.
(författare)
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Myocardial velocities measured during adenosine, dobutamine and supine bicycle exercise : a tissue Doppler study in healthy volunteers
- 2004
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 24:5, s. 281-288
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dobutamine stress echocardiography (DSE) quantified by tissue Doppler (TVI) have improved the diagnostic capacity of the procedure. Quantification of other stress modalities, e.g. adenosine stress echo (ASE) and exercise stress echocardiography (ESE) are necessary for assessing any pathophysiological differences in different forms of stress. Methods: Ten healthy individuals underwent ASE, DSE, and ESE during a span of 2-5 days. Left ventricular (LV) apical images at rest and peak stress (max) were postprocessed using TVI on a GE System FiVe equipment. ECG-derived QRS duration (QRSD, ms), heart rate (HR, bpm), TVI-estimated basal systolic velocities (S2V, cm s(-1)), ejection time (S2T, ms) and strain (S, %) were computed off-line and compared. Longitudinal displacement imaging, tissue tracking, was also made. Results: Data for ASE, DSE and ESE during peak stress were (HR: 84 +/- 12***, 142 +/- 19, 137 +/- 27; P0.05) response at a much lower HR indicates that adenosine has minor effects on contraction presumably secondary to vasodilatation. Powerful chronotropic response to DSE and ESE is probably prerequisite for strong velocity response at the expense of strain and displacement. TVI-assisted stress echocardiography thereby shows different LV systolic response in healthy individuals, depending on stress modality.
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| 9. |
- Sarkar, N., et al.
(författare)
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Effects of intramyocardial injection of phVEGF-A(165) as sole therapy in patients with refractory coronary artery disease - 12-month follow-up : Angiogenic gene therapy
- 2001
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 250:5, s. 373-381
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To test the safety and bioactivity of phVEGF-A(165) after intramyocardial injection during 12-month follow-up. Design. Open-labelled study. Subjects. Inclusion criteria were angina pectoris, Canadian Cardiovascular Society (CCS) class III-IV, unamenable to further revascularization, ejection fraction (EF) >30%, perfusion defects extending over >10% of the anterolateral left ventricle wall detectable with adenosine single photon emission computerized tomography (SPECT) and at least one patent vessel visible by coronary angiography. Seven of 39 patients referred for gene therapy were included. Intervention. Via a mini-thoracotomy under general anaesthesia, phVEGF-A(165) was injected directly into the myocardium at four sites in the anterolateral region of the left ventricle. Results. Operative procedures were uneventful. Perioperative release of myocardial markers and electrocardiogram (ECG) changes were detected in two patients. There were no perioperative deaths but one patient died 7 months postoperatively because of myocardial infarction. Plasma vascular endothelial growth factor (VEGF)-A levels increased two to threefold peaking 6 days postoperatively (P<0.004) and returning to baseline by day 30. A significant reduction in angina pectoris was reported. The CCS class improved from 3.30.2 to 1.9 +/-0.3 (P<0.01) and nitroglycerine intake decreased from 3915 to 12 +/-5 tablets week(-1) (P<0.001) 2 months after gene transfer. Improvements remained after 12 months when nitroglycerine consumption approached zero. Improved myocardial function in the phVEGF-A(165) injection region was documented in all patients (P<0.016) by tissue velocity imaging (TVI). Reduced reversible ischaemia was detected by adenosine SPECT in four patients. Improved collateralization was detected in four patients with coronary angiography. Conclusion. Intramyocardial injection of phVEGF-A(165) is safe and may lead to improved myocardial perfusion and function with longstanding symptomatic relief in end-stage angina pectoris. Based on these results this therapeutic potential is being tested in a double-blind placebo controlled multicentre trial, EUROINJECT ONE.
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| 10. |
- Storaa, C., et al.
(författare)
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Distribution of left ventricular longitudinal peak systolic strain and impact of low frame rate
- 2004
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Ingår i: Ultrasound in Medicine and Biology. - : Elsevier BV. - 0301-5629 .- 1879-291X. ; 30:8, s. 1049-1055
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Tidskriftsartikel (refereegranskat)abstract
- The myocardium has complex 3-D motion that is frequently described using ultrasound (US) Doppler techniques that are limited to recording velocities in one dimension only. Studies using 3-D tagged magnetic resonance show that the myocardium has strain components with varying angles throughout the myocardium. Despite this, there seems to be a belief that the left ventricular longitudinal strain distribution should be homogeneous. When measuring myocardial strain, there are several parameters for the clinician to decide on, one of them being recording frame rate. The current study aims to further investigate the alleged homogeneity of the longitudinal myocardial strain distribution and to discover the impact that the frame rate has on these measurements. Myocardial strain was measured in 43 healthy individuals at different frame rates. Analysis of variance results clearly demonstrate that the strain is not uniformly distributed over the wall; there seems to be an increasing strain from apex toward the base. However, subjects exist with different distributions; thus, it is not possible to conclude that certain strain patterns are normal. Reduced frame rate had a highly significant impact on the measured strain results and it is seen that, at low frame rates, the strain values were reduced. (E-mail: Camilia.Storaa@labmed.ki.se)
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