Left Ventricular Pressure-Volume Relationships in Patients Measured with the Conductance Catherer and Inferior Vena Caval Balloon Occlusion

Author(s):  
W. Lowell Maughan ◽  
David A. Kass
1983 ◽  
Vol 245 (5) ◽  
pp. H741-H748 ◽  
Author(s):  
W. Y. Lew ◽  
M. M. LeWinter

We employed sonomicrometers in open-chest dogs to study lengthening of short segments of circumferentially oriented myocardium located at the base, midportion, and apex of the anterior left ventricular free wall. Left ventricular pressure was varied by inferior vena caval occlusion and volume expansion. Diastole was divided into rapid and slow lengthening phases. Rapid lengthening was completed first at the basal site at each of three successive levels of left ventricular diastolic pressure (LVDP). At the base, significant further lengthening occurred during the slow lengthening phase while at the apex virtually all lengthening was completed during the rapid phase. At low LVDPs, peak lengthening rates (dl/dt) were greatest at the apex. As LVDP was increased, regional differences in dl/dt diminished. These results indicate that there is regional variation in the timing of the phases of diastole and in lengthening patterns of the left ventricle. The volume-dependent variation in lengthening rates that we observed is consistent with the concept of regional differences in elastic recoil, which may contribute to active ventricular filling.


Circulation ◽  
1995 ◽  
Vol 91 (7) ◽  
pp. 2010-2017 ◽  
Author(s):  
J.J. Schreuder ◽  
F.H. van der Veen ◽  
E.T. van der Velde ◽  
F. Delahaye ◽  
O. Alfieri ◽  
...  

1992 ◽  
Vol 262 (1) ◽  
pp. H68-H77
Author(s):  
F. L. Abel ◽  
R. R. Zhao ◽  
R. F. Bond

Effects of ventricular compression on maximally dilated left circumflex coronary blood flow were investigated in seven mongrel dogs under pentobarbital anesthesia. The left circumflex artery was perfused with the animals' own blood at a constant pressure (63 mmHg) while left ventricular pressure was experimentally altered. Adenosine was infused to produce maximal vasodilation, verified by the hyperemic response to coronary occlusion. Alterations of peak left ventricular pressure from 50 to 250 mmHg resulted in a linear decrease in total circumflex flow of 1.10 ml.min-1 x 100 g heart wt-1 for each 10 mmHg of peak ventricular to coronary perfusion pressure gradient; a 2.6% decrease from control levels. Similar slopes were obtained for systolic and diastolic flows as for total mean flow, implying equal compressive forces in systole as in diastole. Increases in left ventricular end-diastolic pressure accounted for 29% of the flow changes associated with an increase in peak ventricular pressure. Doubling circumferential wall tension had a minimal effect on total circumflex flow. When the slopes were extrapolated to zero, assuming linearity, a peak left ventricular pressure of 385 mmHg greater than coronary perfusion pressure would be required to reduce coronary flow to zero. The experiments were repeated in five additional animals but at different perfusion pressures from 40 to 160 mmHg. Higher perfusion pressures gave similar results but with even less effect of ventricular pressure on coronary flow or coronary conductance. These results argue for an active storage site for systolic arterial flow in the dilated coronary system.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingtao Na ◽  
Haifeng Jin ◽  
Xin Wang ◽  
Kan Huang ◽  
Shuang Sun ◽  
...  

Abstract Background Heart failure (HF) is a clinical syndrome characterized by left ventricular dysfunction or elevated intracardiac pressures. Research supports that microRNAs (miRs) participate in HF by regulating  targeted genes. Hence, the current study set out to study the role of HDAC3-medaited miR-18a in HF by targeting ADRB3. Methods Firstly, HF mouse models were established by ligation of the left coronary artery at the lower edge of the left atrial appendage, and HF cell models were generated in the cardiomyocytes, followed by ectopic expression and silencing experiments. Numerous parameters including left ventricular posterior wall dimension (LVPWD), interventricular septal dimension (IVSD), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LEVDP), heart rate (HR), left ventricular pressure rise rate (+ dp/dt) and left ventricular pressure drop rate (-dp/dt) were measured in the mice. In addition, apoptosis in the mice was detected by means of TUNEL staining, while RT-qPCR and Western blot analysis were performed to detect miR-18a, HDAC3, ADRB3, cMyb, MMP-9, Collagen 1 and TGF-β1 expression patterns. Dual luciferase reporter assay validated the targeting relationship between ADRB3 and miR-18a. Cardiomyocyte apoptosis was determined by means of flow cytometry. Results HDAC3 and ADRB3 were up-regulated and miR-18a was down-regulated in HF mice and cardiomyocytes. In addition, HDAC3 could reduce the miR-18a expression, and ADRB3 was negatively-targeted by miR-18a. After down-regulation of HDAC3 or ADRB3 or over-expression of miR-18a, IVSD, LVEDD, LVESD and LEVDP were found to be decreased but LVPWD, LVEF, LVFS, LVSP, + dp/dt, and −dp/dt were all increased in the HF mice, whereas fibrosis, hypertrophy and apoptosis of HF cardiomyocytes were declined. Conclusion Collectively, our findings indicate that HDAC3 silencing confers protection against HF by inhibiting miR-18a-targeted ADRB3.


2010 ◽  
Vol 196 ◽  
pp. S253
Author(s):  
A. Simonnard ◽  
A.M. Bétat ◽  
S. Loriot ◽  
R. Forster

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