Myocardial function of the interventricular septum. Effects of right and left ventricular pressure loading before and after pericardiotomy in dogs.

Abnormal early septal motion observed in patients with left bundle brunch block (LBBB) has been explained as a difference in right-to-left ventricular pressure. The interventricular septum was thought to be displaced passively into the LV because the right ventricle contracts prior to the LV and the right ventricular pressure exceeds the LV pressure during early systolic phase. Assuming that this theory is right, the interventricular septal wall would be stretched and shown positive strain value in circumferential and longitudinal directions during early systolic phase. We investigated the mechanism of the early septal motion with LBBB using speckle tracking imaging (STI). Methods: Systolic septal motion on the middle LV portion level was analyzed in 44 patients with complete LBBB (mean QRS duration 166 ± 35 ms) using M-mode echocardiography and speckle tracking imaging (STI). Time from onset of QRS configuration to peak circumferential strain and longitudinal strain were measured in parasternal short axis and apical views by STI. Furthermore, 20 healthy individuals (mean QRS duration 84 ± 6 ms) were also analyzed. Changes in LV pressure and septal strain were simultaneously measured to evaluate the relationship between them in 6 patients with LBBB. Results: Septal displacement into the LV was early and abrupt on M-mode echocardiograms from all patients with LBBB. During this displacement, the STI of the interventricular septum of all patients showed negative strain in both the circumferential and longitudinal directions. Furthermore, early septal displacement almost coincided with peak negative strain. Time to peak septal strain in LBBB patients was significantly shorter than in normal controls in the circumferential (296 ± 80 vs. 356 ± 30 ms; p < 0.05) and longitudinal (317 ± 104 vs. 369 ± 17 ms; p < 0.05) directions. The peak of septal negative strain was followed by an increase in LV pressure in all patients. Conclusion: Early motion of the interventricular septum is provoked by its active contraction in LBBB. The septal contraction starts very early and almost isotonically toward a very low load. However, further shortening is suppressed by a subsequently increased load of pressure elevation due to the contraction of other LV segments.

Download Full-text

Left Ventricular Pressure-Volume Relationships Before and After Cardiomyoplasty in Patients With Heart Failure

Circulation ◽

10.1161/01.cir.96.9.2978 ◽

1997 ◽

Vol 96 (9) ◽

pp. 2978-2986 ◽

Cited By ~ 39

Author(s):

J.J. Schreuder ◽

F.H. van der Veen ◽

E.T. van der Velde ◽

F. Delahaye ◽

O. Alfieri ◽

...

Keyword(s):

Heart Failure ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Ventricular Pressure ◽

Patients With Heart Failure ◽

Before And After

Download Full-text

Effects of left ventricular pressure reductions on right ventricular systolic performance

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1989.257.6.h1878 ◽

1989 ◽

Vol 257 (6) ◽

pp. H1878-H1885 ◽

Cited By ~ 4

Author(s):

E. Chow ◽

D. J. Farrar

Keyword(s):

Right Ventricular ◽

Interventricular Septum ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Ventricular Pressure ◽

Segment Length ◽

Stroke Work ◽

Ventricular Performance ◽

Right Ventricular Performance ◽

Intact Heart

Reductions in left ventricular pressure (LVP) have been shown to produce a leftward shift of the interventricular septum and to reduce left ventricular contribution to right ventricular performance. To evaluate the magnitude of this contribution in the intact heart, five anesthetized pigs were implanted with a left prosthetic ventricle to gradually decrease LVP while maintaining arterial systemic pressure. Three descriptors of RV global and regional systolic function were studied in the septum to free wall (RVSFW) and anterior to posterior (RVAP) dimensions and in an outflow tract segment length (RVSL), during both steady state and transient inferior vena cava occlusion. LVP gradual reduction from 102 +/- 4 to 11 +/- 3 mmHg (90% decrease in peak systolic pressure) produced no changes in the RV global stroke work curve or in the RVAP and RVSL pressure-dimension relationships. However, the reduction in LVP resulted in parallel shifts in the RVSFW dimension, with 16.6 +/- 6.7% increase in the intercept D(o) of the end-systolic relationship and 16.5 +/- 2.5% increase in D(o) of the dimensional stroke work relationship, with no significant changes in their respective slopes as calculated by linear regression. Therefore, in the normal intact heart, large reductions in left ventricular pressure affect the geometry of the right ventricle because of septal shifting, but there is a negligible net effect of this anatomic ventricular interaction on overall right ventricular performance.

Download Full-text

Effects of Desflurane and Sevoflurane on Length-dependent Regulation of Myocardial Function in Coronary Surgery Patients

Anesthesiology ◽

10.1097/00000542-200108000-00016 ◽

2001 ◽

Vol 95 (2) ◽

pp. 357-363 ◽

Cited By ~ 20

Author(s):

Stefan G. De Hert ◽

Philippe J. Van der Linden ◽

Pieter W. ten Broecke ◽

Kris T. Vermeylen ◽

Inez E. Rodrigus ◽

...

Keyword(s):

Left Atrial ◽

Myocardial Function ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Ventricular Pressure ◽

Coronary Surgery ◽

Pressure Gradients ◽

Pressure Development ◽

Ventricular Response ◽

End Tidal

Background Desflurane and sevoflurane have negative inotropic effects. The current study investigated whether these effects resulted in an altered left ventricular response to increased cardiac load and affected length-dependent regulation of myocardial function. Length-dependent regulation of myocardial function refers to the ability of the heart to improve its performance when preload is increased. Methods A high-fidelity pressure catheter was positioned in the left ventricle and left atrium in 20 coronary surgery patients with a preoperative ejection fraction greater than 40%. Studies were performed before the initiation of cardiopulmonary bypass. Left ventricular response to increased cardiac load, obtained by leg elevation, was assessed during control conditions and during increasing concentrations of desflurane (2, 4, and 6% end tidal; n = 10) or sevoflurane (1, 2, and 3% end tidal; n = 10). Effects on contraction were evaluated by analysis of changes in maximal rate of pressure development. Effects on relaxation were assessed by analysis of changes in minimum rate of pressure development and by analysis of the load dependence of myocardial relaxation (R = slope of the relation between time constant tau of isovolumic relaxation and end-systolic pressure). Peak left atrial-left ventricular pressure gradients were analyzed during early left ventricular filling. Results With both desflurane and sevoflurane, maximal and minimum rates of pressure development decreased while tau increased. Peak left atrial-left ventricular pressure gradients remained unchanged. The hemodynamic effects of leg elevation were similar at the different concentrations. Changes in parameters of contraction and relaxation during leg elevation were coupled and were not altered by desflurane or sevoflurane. Conclusions Despite their negative inotropic and lusitropic effects, neither desflurane nor sevoflurane adversely affect length-dependent regulation of left ventricular function. In the conditions of our study, the ability of the left ventricular to respond to increased cardiac load is not altered by the use of desflurane or sevoflurane.

Download Full-text

Left Ventricular Pressure Volume Loop Measurements Using Conductance Catheters to Assess Myocardial Function in Mice

Methods in Molecular Biology - Cardiac Regeneration ◽

10.1007/978-1-0716-0668-1_3 ◽

2020 ◽

pp. 33-41

Author(s):

Tilman Ziegler ◽

Karl-Ludwig Laugwitz ◽

Christian Kupatt

Keyword(s):

Myocardial Function ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Ventricular Pressure

Download Full-text

Value of Left Ventricular Pressure–Strain Loops in the Quantitative Assessment of Myocardial Function in Patients with Nonobstructive Hypertrophic Cardiomyopathy

10.21203/rs.3.rs-569990/v1 ◽

2021 ◽

Author(s):

Hong-ling Ran ◽

zhe-yuan Zhang ◽

Jia Hu ◽

Xin-chun Yuan ◽

Zeng Xi ◽

...

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Myocardial Function ◽

Early Stage ◽

Left Ventricular Pressure ◽

Left Ventricular ◽

Ventricular Pressure ◽

Control Group ◽

Imaging Method ◽

Chamber View ◽

Significant Difference

Abstract Purposes: The purposes of this study were to use noninvasive Left ventricular pressure-strain loops (LV-PSLs) to compare the various myocardial work indices in patients with noninvasive hypertrophic cardiomyopathy (NHCM) and to evaluate the clinical application of myocardial work to the evaluation of NHCM patients.Method: 80 NHCM patients and 45 healthy subjects were enrolled. All the selectors underwent Echocardiography examination. Dynamic images of standard apical three-chamber, four-chamber, and two-chamber view were collected, the myocardial work indices of left ventricle were measured by LV-PSLs. The difference in myocardial work indices between two groups and various myocardial work indices in different types of hypertrophic cardiomyopathy were compared.Results: There were no significant difference in the general clinical data between the NHCM group and control; myocardial work indices of HCM were lower compared with control group except global work waste (GWW); The myocardial work between all three types of NHCMs was also different, particularly in global construction work (GCW); the intra- and inter observer consistency of myocardial work indices were good.Conclusion: Myocardial work assessed by the LV-PSLs could reflect myocardial work in NHCM patients at the early stage and quantitatively assess regional and global myocardial function, providing an accurate and convenient imaging method for early detection of the subclinical status of NHCM patients.

Download Full-text