| 1. |
|
|
| 2. |
- Steding-Ehrenborg, Katarina, et al.
(författare)
-
Hydraulic force is a novel mechanism of diastolic function which may contribute to decreased diastolic filling in HFpEF and facilitate filling in HFrEF
- 2021
-
Ingår i: Journal of Applied Physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 130:4, s. 993-1000
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A hydraulic force generated by blood moving the atrio-ventricular plane is a novel mechanism of diastolic function. The direction and magnitude of the force is dependent on the geometrical relationship between the left atrium and ventricle and is measured as the short-axis atrio-ventricular area difference (AVAD). In short, the net hydraulic force acts from a larger area towards a smaller. It is currently unknown how cardiac remodeling affects this mechanism. The aim of the study was therefore to investigate this diastolic mechanism in patients with pathological or physiological remodeling.METHODS: 70 subjects (n=11 heart failure with preserved ejection fraction (HFpEF), n=10 heart failure with reduced ejection fraction (HFrEF), n=7 signs of isolated diastolic dysfunction, n=10 hypertrophic cardiomyopathy (HCM), n=10 cardiac amyloidosis, n=18 triathletes and n=14 controls) were included. Subjects underwent Cardiac MR and short-axis images of the left atrium and ventricle were delineated. AVAD was calculated as ventricular area minus atrial area and used as an indicator of net hydraulic force.RESULTS: At the onset of diastole, AVAD in HFpEF was median -9.2 cm2 versus -4.4 cm2 in controls, p=0.02). The net hydraulic force was directed towards the ventricle for both, but larger in HFpEF. HFrEF was the only group with a positive median value 11.6 cm2 and net hydraulic force was throughout diastole directed towards the atrium.CONCLUSION: The net hydraulic force may impede cardiac filling throughout diastole in HFpEF, worsening diastolic dysfunction. In contrast, it may work favorably in patients with dilated ventricles and aid ventricular filling.
|
|
| 3. |
- Axelsson, Jimmy, et al.
(författare)
-
Ejection fraction in left bundle branch block is disproportionately reduced in relation to amount of myocardial scar
- 2018
-
Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 51:6, s. 1071-1076
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The relationship between left ventricular (LV) ejection fraction (EF) and LV myocardial scar can identify potentially reversible causes of LV dysfunction. Left bundle branch block (LBBB) alters the electrical and mechanical activation of the LV. We hypothesized that the relationship between LVEF and scar extent is different in LBBB compared to controls. Methods: We compared the relationship between LVEF and scar burden between patients with LBBB and scar (n = 83), and patients with chronic ischemic heart disease and scar but no electrocardiographic conduction abnormality (controls, n = 90), who had undergone cardiovascular magnetic resonance (CMR) imaging at one of three centers. LVEF (%) was measured in CMR cine images. Scar burden was quantified by CMR late gadolinium enhancement (LGE) and expressed as % of LV mass (%LVM). Maximum possible LVEF (LVEFmax) was defined as the function describing the hypotenuse in the LVEF versus myocardial scar extent scatter plot. Dysfunction index was defined as LVEFmax derived from the control cohort minus the measured LVEF. Results: Compared to controls with scar, LBBB with scar had a lower LVEF (median [interquartile range] 27 [19–38] vs 36 [25–50] %, p < 0.001), smaller scar (4 [1–9] vs 11 [6–20] %LVM, p < 0.001), and greater dysfunction index (39 [30–52] vs 21 [12–35] % points, p < 0.001). Conclusions: Among LBBB patients referred for CMR, LVEF is disproportionately reduced in relation to the amount of scar. Dyssynchrony in LBBB may thus impair compensation for loss of contractile myocardium.
|
|
| 4. |
|
|
| 5. |
- Bacharova, Ljuba, et al.
(författare)
-
ISE/ISHNE expert consensus statement on the ECG diagnosis of left ventricular hypertrophy : The change of the paradigm
- 2023
-
Ingår i: Annals of Noninvasive Electrocardiology. - 1082-720X. ; 29:1, s. e13097-
-
Tidskriftsartikel (refereegranskat)abstract
- The ECG diagnosis of LVH is predominantly based on the QRS voltage criteria. The classical paradigm postulates that the increased left ventricular mass generates a stronger electrical field, increasing the leftward and posterior QRS forces, reflected in the augmented QRS amplitude. However, the low sensitivity of voltage criteria has been repeatedly documented. We discuss possible reasons for this shortcoming and proposal of a new paradigm. The theoretical background for voltage measured at the body surface is defined by the solid angle theorem, which relates the measured voltage to spatial and non-spatial determinants. The spatial determinants are represented by the extent of the activation front and the distance of the recording electrodes. The non-spatial determinants comprise electrical characteristics of the myocardium, which are comparatively neglected in the interpretation of the QRS patterns. Various clinical conditions are associated with LVH. These conditions produce considerable diversity of electrical properties alterations thereby modifying the resultant QRS patterns. The spectrum of QRS patterns observed in LVH patients is quite broad, including also left axis deviation, left anterior fascicular block, incomplete and complete left bundle branch blocks, Q waves, and fragmented QRS. Importantly, the QRS complex can be within normal limits. The new paradigm stresses the electrophysiological background in interpreting QRS changes, i.e., the effect of the non-spatial determinants. This postulates that the role of ECG is not to estimate LV size in LVH, but to understand and decode the underlying electrical processes, which are crucial in relation to cardiovascular risk assessment.
|
|
| 6. |
- Cain, Peter A, et al.
(författare)
-
Age and gender specific normal values of left ventricular mass, volume and function for gradient echo magnetic resonance imaging: a cross sectional study.
- 2009
-
Ingår i: BMC medical imaging. - : Springer Science and Business Media LLC. - 1471-2342. ; 9:2
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge about age-specific normal values for left ventricular mass (LVM), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) by cardiac magnetic resonance imaging (CMR) is of importance to differentiate between health and disease and to assess the severity of disease. The aims of the study were to determine age and gender specific normal reference values and to explore the normal physiological variation of these parameters from adolescence to late adulthood, in a cross sectional study.
|
|
| 7. |
- Cain, Peter, et al.
(författare)
-
Physiological determinants of the variation in left ventricular mass from early adolescence to late adulthood in healthy subjects
- 2005
-
Ingår i: Clin Physiol Funct Imaging. - 1475-0961. ; 25:6, s. 332-9
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The physiological determinants of left ventricular mass (LVM) measured by cardiac magnetic resonance (CMR) imaging are not well defined as prior investigators have studied either adults or adolescents in isolation or have not strictly excluded hypertension or accounted for the effects of exercise habits, haemodynamic, demographic, or body shape characteristics. METHODS: A total of 102 healthy volunteers (12-81 years, 53 males) underwent CMR. All parameters [unstandardized and adjusted for body surface area (BSA)] were analysed according to gender and by adolescence versus adulthood (adolescents <20 years, adults > or = 20 years). The influence of haemodynamic factors, exercise, and demographic factors on LVM were determined with multivariate linear regression. Results: LVM rose during adolescence and declined in adulthood. LVM and LVMBSA were higher in males both in adults (LVM: 188 +/- 22 g versus 139 +/- 21 g, P < 0.001; LVMBSA: 94 +/- 11 g m(-2) versus 80 +/- 11 g m(-2), P < 0.001) and in adolescents when adjusted for BSA (LVM: 128 +/- 29 g versus 107 +/- 20 g, P = 0.063; LVMBSA: 82 +/- 8 g m(-2) versus 71 +/- 10 g m(-2), P = 0.025). In adults, systolic blood pressure (SBP) and self-reported physical activity increased while meridional and circumferential wall stress were constant with age. Multivariate regression analysis revealed age, gender, and BSA as the major determinants of LVM (global R2 = 0.69). CONCLUSIONS: Normal LVM shows variation over a broad age range in both genders with a rise in adolescence and subsequent decline with increasing age in adulthood despite an increase in SBP and physical activity. BSA, age, and gender were found to be major contributors to the variation in LVM in healthy adults, while haemodynamic factors, exercise, and wall stress were not.
|
|
| 8. |
|
|
| 9. |
- Cain, Peter, et al.
(författare)
-
Quantitative polar representation of left ventricular myocardial perfusion, function and viability using SPECT and cardiac magnetic resonance: initial results.
- 2005
-
Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961. ; 25:4, s. 215-222
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The clinical management of patients with coronary artery disease (CAD) often involves a complex assessment of the extent and severity of changes in left ventricular (LV) myocardial perfusion, function and viability. We aimed to explore the feasibility of integrative quantitative representation of LV perfusion, function and viability in adjacent polar plots. In order to assess the clinical usefulness of the quantitative methods, we also explored the relationship and determined the agreement between visual scoring and quantitative measurement of regional perfusion and function. Methods: Ten patients with CAD underwent rest and stress 99mTc-tetrofosmin single photon emission computed tomography (SPECT) and cardiac magnetic resonance (CMR) imaging. Software was developed in-house for generating polar plots from semi-automatic quantification of rest and stress perfusion from SPECT, function from cine CMR and viability from delayed contrast enhancement (DE) CMR. The agreement between visual assessment and quantification of both perfusion and function was tested by Kendall's coefficient of concordance (W). Results: Polar plots were created using quantitative data from the semi-automatic analysis of perfusion, function and viability. Kendall's W for agreement between quantitative measurement and visual scoring was 1·0 (P<0·001) for perfusion and 0·85 (P<0·001) for function. Conclusions: Side-by-side quantitative polar representation of LV perfusion, function and viability is feasible and may aid in the complex assessment of these parameters. The agreement between quantitative measurement and visual scoring was very good for both perfusion and function.
|
|
| 10. |
- Carlsson, Marcus, et al.
(författare)
-
Atrioventricular plane displacement is the major contributor to left ventricular pumping in healthy adults, athletes, and patients with dilated cardiomyopathy
- 2007
-
Ingår i: American Journal of Physiology: Heart and Circulatory Physiology. - : American Physiological Society. - 1522-1539 .- 0363-6135. ; 292:3, s. 1452-1459
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies using echocardiography in healthy subjects have reported conflicting data regarding the percentage of the stroke volume ( SV) of the left ventricle ( LV) resulting from longitudinal and radial function, respectively. Therefore, the aim was to quantify the percentage of SV explained by longitudinal atrioventricular plane displacement ( AVPD) in controls, athletes, and patients with decreased LV function due to dilated cardiomyopathy ( DCM). Twelve healthy subjects, 12 elite triathletes, and 12 patients with DCM and ejection fraction below 30% were examined by cine magnetic resonance imaging. AVPD and SV were measured in long- and short- axis images, respectively. The percentage of the SV explained by longitudinal function ( SVAVPD%) was calculated as the mean epicardial area of the largest short- axis slices in end diastole multiplied by the AVPD and divided by the SV. SV was higher in athletes [ 140 +/- 4 ml ( mean +/- SE), P = 0.009] and lower in patients ( 72 +/- 7 ml, P < 0.001) when compared with controls ( 116 +/- 6 ml). AVPD was similar in athletes ( 17 +/- 1 mm, P = 0.45) and lower in patients ( 7 +/- 1 mm, P = 0.001) when compared with controls ( 16 +/- 0 mm). SVAVPD% was similar both in athletes ( 57 +/- 2%, P = 0.51) and in patients ( 67 +/- 4%, P = 0.24) when compared with controls ( 60 +/- 2%). In conclusion, longitudinal AVPD is the primary contributor to LV pumping and accounts for similar to 60% of the SV. Although AVPD is less than half in patients with DCM when compared with controls and athletes, the contribution of AVPD to LV function is maintained, which can be explained by the larger short- axis area in DCM.
|
|
