Indexes of diastolic RV function: load dependence and changes after chronic RV pressure overload in lambs

2002 ◽  
Vol 282 (4) ◽  
pp. H1350-H1358 ◽  
Author(s):  
Boudewijn P. J. Leeuwenburgh ◽  
Paul Steendijk ◽  
Willem A. Helbing ◽  
Jan Baan
Keyword(s):  
Diastolic Function ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Pressure Overload ◽  
Ventricular Performance ◽  
Load Dependence ◽  
Stiffness Constant ◽  
Diastolic Stiffness ◽  
Pressure Volume Relationship ◽  
Preload Reduction

Diastolic function is a major determinant of ventricular performance, especially when loading conditions are altered. We evaluated biventricular diastolic function in lambs and studied possible load dependence of diastolic parameters [minimum first derivative of pressure vs. time (dP/d t min) and time constant of isovolumic relaxation (τ)] in normal ( n = 5) and chronic right ventricular (RV) pressure-overloaded ( n = 5) hearts by using an adjustable band on the pulmonary artery (PAB). Pressure-volume relations were measured during preload reduction to obtain the end-diastolic pressure-volume relationship (EDPVR). In normal lambs, absolute dP/d t min and τ were lower in the RV than in the left ventricle whereas the chamber stiffness constant ( b) was roughly the same. After PAB, RV τ and dP/d t min were significantly higher compared with control. The RV EDPVR indicated impaired diastolic function. During acute pressure reduction, both dP/d t min and τ showed a relationship with end-systolic pressure. These relationships could explain the increased dP/d t min but not the increased τ-value after banding. Therefore, the increased τ after banding reflects intrinsic myocardial changes. We conclude that after chronic RV pressure overload, RV early relaxation is prolonged and diastolic stiffness is increased, both indicative of impaired diastolic function.

Contraction-Relaxation Coupling and Impaired Left Ventricular Performance in Coronary Surgery Patients 

1999 ◽  
Vol 90 (3) ◽  
pp. 748-757 ◽  
Author(s):  
Stefan G. De Hert ◽  
Thierry C. Gillebert ◽  
Pieter W. Ten Broecke ◽  
Els Mertens ◽  
Inez E. Rodrigus ◽  
...  
Keyword(s):  
Diastolic Pressure ◽  
Linear Regression Analysis ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Coronary Surgery ◽  
Tight Coupling ◽  
Fixed Rate ◽  
Ventricular Performance ◽  
Load Dependence ◽  
Contraction And Relaxation

Background Dependence of left ventricular (LV) relaxation on cardiac systolic load is a function of myocardial contractility. The authors hypothesized that, if a tight coupling would exist between LV contraction and relaxation, the changes in relaxation rate with an increase in cardiac systolic load would be related to the changes in LV contraction. Methods Coronary surgery patients (n = 120) with preoperative ejection fraction >40% were included. High-fidelity LV pressure tracings (n = 120) and transgastric transesophageal echocardiographic data (n = 40) were obtained. Hearts were paced at a fixed rate of 90 beats/min. Effects on contraction were evaluated by analysis of changes in dP/dt(max) and stroke area. Effects on relaxation were assessed by analysis of R (slope of the relation between tau and end-systolic pressure). Correlations were calculated with linear regression analysis using Pearson's coefficient r. Results Baseline LV end-diastolic pressure was 10+/-3 mm Hg (mean +/- SD). During leg raising, systolic LV pressure increased from 93+/-9 to 107+/-11 mm Hg. The change in dP/dt(max) was variable and ranged from -181 to +254 mm Hg/s. A similar variability was observed with the changes in stroke area, which ranged from -2.0 to +5.5 cm2. Changes in dP/dt(max) and in stroke area were closely related to individual R values (r = 0.87, P<0.001; and r = 0.81, P<0.001, respectively) and to corresponding changes in LV end-diastolic pressure (r = 0.81, P< 0.001; and r = 0.74, P<0.001, respectively). Conclusions A tight coupling was observed between contraction and relaxation. Leg raising identified patients who developed a load-dependent impairment of LV performance and increased load dependence of LV relaxation.

Abstract 10878: Validation of Non-invasive Measures of Diastolic Function in Children: A Simultaneous Echocardiography and Conductance Catheterization Study

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Shahryar M Chowdhury ◽  
Ryan J Butts ◽  
Anthony M Hlavacek ◽  
Carolyn L Taylor ◽  
Varsha M Bandisode ◽  
...  
Keyword(s):  
Diastolic Function ◽  
Diastolic Pressure ◽  
Ductus Arteriosus ◽  
Left Ventricular ◽  
Balloon Occlusion ◽  
Heart Catheterization ◽  
Active Relaxation ◽  
Non Invasive ◽  
Stiffness Constant ◽  
Lv Diastolic Function

Introduction: The accuracy of echocardiography in evaluating left ventricular (LV) diastolic function has not been validated in children. The objective of this study was to compare echocardiographic and gold-standard measures of LV diastolic function in children. Methods: Patients undergoing routine left heart catheterization were prospectively enrolled. Pressure-volume loops (PVL) were obtained via conductance catheters. The end-diastolic pressure-volume relationship was obtained via balloon occlusion of the vena cavae. PVL measures of diastolic function were divided into early active relaxation (the isovolumic relaxation time constant, tau), and ventricular stiffness (the chamber stiffness constant, β). End-diastolic pressure (EDP) was also recorded. Echocardiographic measures of diastolic function were derived from spectral Doppler, tissue Doppler, and 2D speckle-tracking. The relationships between PVL and echocardiographic measures were determined using Spearman’s correlation. Results: Of 24 patients, 18 patients were s/p heart transplant, 5 patients had a small patent ductus arteriosus or coronary fistula. Mean age was 9.1 ± 5.6 years. The median τ was 24.9 ms (IQR 22.8 - 28.4 ms), median β was 0.094 (IQR 0.035 - 0.154), and median EDP was 9 mmHg (IQR 8 - 13 mmHg). Statistically significant correlations between invasive and echocardiographic measures of diastolic function are reported in the Table. No echocardiographic measures correlated with β. Conclusion: Early diastolic echocardiographic measures correlate with tau and may accurately represent early active relaxation in children. Modest associations exist between echocardiographic measures and EDP. The use of these non-invasive measures in accurately assessing LV diastolic function appears promising in children. However, no echocardiographic measures correlate with chamber stiffness. The development of such measures merits further study.

Colchicine attenuates left ventricular hypertrophy but preserves cardiac function of aortic-constricted rats

2003 ◽  
Vol 94 (4) ◽  
pp. 1627-1633 ◽  
Author(s):  
Beatriz S. Scopacasa ◽  
Vicente P. A. Teixeira ◽  
Kleber G. Franchini
Keyword(s):  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Pressure Overload ◽  
Colchicine Treatment ◽  
Average Diameter ◽  
Left Ventricular ◽  
Lv Function ◽  
Right Ventricular Mass ◽  
Lv Mass ◽  
Phenylephrine Infusion

To investigate the effects of colchicine on left ventricular (LV) function and hypertrophy (LVH) of rats subjected to constriction of transverse aorta (TAoC), we evaluated SO (sham operated, vehicle; n = 25), SO-T (sham operated, colchicine 0.4 mg/kg body wt ip daily; n = 38), TAoC (vehicle; n = 37), and TAoC-T (TAoC, colchicine; n = 34) on the 2nd, 6th, and 15th day after surgery. Colchicine attenuated LVH of TAoC-T compared with TAoC rats, as evaluated by ratio between LV mass (LVM) and right ventricular mass, LV wall thickness, and average diameter of cardiac myocytes. Systolic gradient across TAoC (∼45 mmHg), LV systolic pressure, LV end-diastolic pressure, and rate of LV pressure increase (+dP/d t) were comparable in TAoC-T and TAoC rats. However, the baseline and increases of LV systolic pressure-to-LVM and +dP/d t-to-LVMratios induced by phenylephrine infusion were greater in TAoC-T and SO-T compared with SO rats. Baseline and increases of +dP/d t-to-LVM ratio were reduced in TAoC compared with SO rats. TAoC rats increased polymerized fraction of tubulin compared with SO, SO-T, and TAoC-T rats. Our results indicate that colchicine treatment reduced LVH to pressure overload but preserved LV function.

scholarly journals Right ventricular diastolic function in canine models of pressure overload, volume overload, and ischemia

2002 ◽  
Vol 283 (5) ◽  
pp. H2140-H2150 ◽  
Author(s):  
Ares Pasipoularides ◽  
Ming Shu ◽  
Ashish Shah ◽  
Scott Silvestry ◽  
Donald D. Glower
Keyword(s):  
Right Ventricular ◽  
Diastolic Function ◽  
Diastolic Pressure ◽  
Systolic Function ◽  
Pressure Overload ◽  
Volume Overload ◽  
Exponential Model ◽  
Filling Pressure ◽  
Sigmoidal Model ◽  
Right Ventricular Diastolic Function

By limiting filling, abnormalities of right ventricular (RV) diastolic function may impair systolic function and affect adaptation to disease. To quantify diastolic RV pressure-volume relations and myocardial compliance (MC), a new sigmoidal model was developed. RV micromanometric and sonomicrometric data in alert dogs at control ( n = 16) and under surgically induced subacute (2–5 wk) RV pressure overload ( n = 6), volume overload ( n = 7), and ischemia ( n = 6) were analyzed. The conventional exponential model detected no changes from control in the passive filling pressure-volume (Ppf-V) relations. The new sigmoidal model revealed significant quantifiable changes in Ppf-V relations. Maximum RV MC (MCmax), attained during early filling, is reduced from control in pressure overload ( P = 0.0016), whereas filling pressure at maximum MC (PMCmax) is increased ( P = 0.0001). End-diastolic RV MC increases significantly in volume overload ( P = 0.0131), whereas end-diastolic pressure is unchanged. In ischemia, MCmax is decreased ( P = 0.0102), with no change in PMCmax. We conclude that the sigmoidal model quantifies important changes in RV diastolic function in alert dog models of pressure overload, volume overload, and ischemia.

Recovery of Systolic and Diastolic Left Ventricular Function Early after Cardiopulmonary Bypass

1996 ◽  
Vol 85 (5) ◽  
pp. 1063-1075 ◽  
Author(s):  
Stefan G. De Hert ◽  
Inez E. Rodrigus ◽  
Luc R. Haenen ◽  
Peter A. De Mulder ◽  
Thierry C. Gillebert
Keyword(s):  
Cardiopulmonary Bypass ◽  
Cardiac Function ◽  
Left Ventricular Function ◽  
Diastolic Function ◽  
Ventricular Function ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Stiffness Constant ◽  
Diastolic Left Ventricular Function ◽  
Volume Relation

Background Impairment of left ventricular function after cardiopulmonary bypass (CPB) is well recognized, but little is known about the time course of recovery of cardiac function early after separation from CPB. Therefore, recovery of left ventricular function was evaluated early after separation from CPB in patients undergoing coronary artery surgery. The authors tried to determine whether this recovery might be attributed to autoregulation of function by preload. Methods Left ventricular pressure was measured with fluid-filled catheters. Data were digitally recorded during increased pressure induced by elevating the legs. Transgastric short-axis echocardiographic views of the left ventricle were simultaneously recorded on videotape. Systolic function was evaluated with the slope (Ees, mmHg/ml) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, ml-1) of the diastolic pressure-volume relation. Cardiac function was assessed before CPB, after termination of CPB, and 5, 10, and 15 min later. Two different separation procedures from CPB were compared: in protocol 1, left ventricular function was documented during the standard procedure (n = 24); in protocol 2, the heart was optimally filled 10 min before separation from CPB (n = 12). Results In protocol 1, Ees was 2.88 +/- 0.21 mmHg/ml (mean +/- SEM) and Kc was 0.012 +/- 0.001 ml-1 before CPB. Within 10 min after separation from CPB, Ees increased from 1.10 +/- 0.32 to 2.92 +/- 0.34 (P = 0.001) and Kc decreased from 0.022 +/- 0.002 to 0.011 +/- 0.001 (P = 0.001). The parameters remained stable thereafter. In protocol 2, Ees was 2.92 +/- 0.51 mmHg/ ml and Kc was 0.011 +/- 0.002 ml-1 before CPB. Depression of systolic and diastolic function was not observed in these patients. At time 0, Ees was 2.46 +/- 0.16 and Kc was 0.012 +/- 0.002. These values remained stable throughout the entire observation period. Conclusions Significant functional recovery was observed early after separation from CPB, which was suggestive of time-dependent changes in both systolic and diastolic left ventricular function induced by preload restoration.

Ventricular performance, pressure-volume relationships, and O2 consumption during hypothermia

1964 ◽  
Vol 206 (1) ◽  
pp. 67-73 ◽  
Author(s):  
R. G. Monroe ◽  
R. H. Strang ◽  
C. G. LaFarge ◽  
J. Levy
Keyword(s):  
Peak Pressure ◽  
Diastolic Pressure ◽  
Isolated Heart ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Ventricular Performance ◽  
Heart Rates ◽  
Performance Pressure ◽  
Air Chamber ◽  
Lower Temperature

Left ventricular performance in the isolated heart of a dog was observed at normal temperatures (37.7 C) and under hypothermia (32.2 C) at comparable heart rates. The peak pressure of isovolumic contractions at the same ventricular end-diastolic pressures averaged 40% higher at the lower temperature. Diastolic pressure-volume relationships were similar at both temperatures. In studies in which the ventricle ejected fluid and performed work the hypothermic ventricle was capable of performing greater work at comparable heart rates, left ventricular end-diastolic pressures, and loading. When the ventricle was allowed to perform work by compressing air into a chamber of constant volume left ventricular oxygen consumption (Vo2) increased with the peak systolic pressure as the temperature was lowered. If the peak systolic pressure was maintained constant by increasing the volume of the air chamber as the temperature was lowered no consistent relationship could be shown between left ventricular Vo2 and the integral of systolic pressure in time which invariably increased with hypothermia.

Single-beat evaluation of left ventricular inotropic state in conscious dogs

1989 ◽  
Vol 256 (1) ◽  
pp. H56-H65 ◽  
Author(s):  
E. C. Lascano ◽  
J. A. Negroni ◽  
J. G. Barra ◽  
A. J. Crottogini ◽  
R. H. Pichel
Keyword(s):  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Conscious Dogs ◽  
Time Data ◽  
Inotropic State ◽  
Volume Relationship ◽  
Pressure Volume Relationship ◽  
Experimental Findings ◽  
Parameter Values

Two competing left ventricular elastic-resistive (ER) models were used to predict parameter values from pressure, volume, and time data of a single ejective beat in conscious dogs during control, enhanced (dobutamine), and decreased (propranolol) inotropic states. The animals were instrumented with three pairs of microcrystals and a transducer to measure intraventricular volume and pressure. Results showed that with the ER nonlinear model (ERNL), parameter values in all animals lay within the physiological range. These were the slope (Emax) and the intercept (V0) of the isovolumic end-systolic pressure-volume relationship (ESPVR), the slope of the end-diastolic pressure-volume relationship (Ed), the time to Emax (Tmax), the normalized time to end of activation (A), and the resistive constant (K). In the two models, the normalized SE of the estimate of data fitting was below 0.2 Emax, as estimated from a single beat, responded to changes in contractility in a significantly more consistent fashion than the slope of ESPVRs (Ees) generated by preload maneuvers in conscious dogs. Single-beat estimated Tmax and K with the ERNL model did also respond consistently to contractility changes, whereas with the elastic resistive linear (ERL) model, K did not reproduce the experimental findings with decreased inotropic state. We conclude that 1) the ERNL model can be employed to assess contractility changes in conscious dogs from data of a single ejective beat, and 2) these changes are better indicated by single-beat estimated Emax than by Ees calculated from conventional ESPVRs.

Abstract 20421: Polarizing State Induced by Adenosine, Lidocaine and Magnesium Administration After Prolonged Circulatory Arrest Improves Cardioprotection and Neuroprotection in a Rat Model of Cardiac Arrest With Extracorporeal Life Support

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Alessio Rungatscher ◽  
Geoffrey P Dobson ◽  
Daniele Linardi ◽  
Elisabetta Milani ◽  
Maddalena Tessari ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cardiac Function ◽  
Life Support ◽  
Diastolic Pressure ◽  
Extracorporeal Life Support ◽  
Circulatory Arrest ◽  
Systolic Pressure ◽  
Stroke Work ◽  
Volume Relationship ◽  
Pressure Volume Relationship

BACKGROUND: Polarized arrest, a new concept of myocardial protection, has been recently demonstrated to improve cardiac function after cardioplegic arrest during cardiac surgery. The present study investigated whether polarizing state after prolonged cardiac arrest would provide cardioprotective and neuroprotective effects after extracorporeal life support (ECLS). METHODS AND RESULTS: Ventricular fibrillation (VF) was induced in male Wistar rats. After 8 min of untreated VF, veno-arterial ECLS was instituted for 60 min inducing mild therapeutic hypothermia (32°C). At the beginning of ECLS animals were randomized to receive a single iv bolus of 4.5 mL/kg of polarizing solution with adenosine (47 μM), lidocaine (92 μM) and MgSO4 (1 mM) or same volume of saline as control. Restoration of spontaneous circulation was higher in rats that received polarizing solution (p = 0.03). After 24 h survival and neurologic deficit scores were improved and histological damage scores and brain TNF-α were attenuated compared to control (all p<0.05). Polarizing solution administration led to better recovery of left ventricle end-systolic pressure-volume relationship (Ees), preload recruitable stroke work (PRSW), end-diastolic pressure-volume relationship (EDPVR) and Tau (p<0.01). Polarized state enhanced phosphorilation of myocardial ERK1 and 2 and Akt, resulting in a lower apoptotic index (TUNEL, p<0.01). CONCLUSIONS: Polarized state induced by adenosine, lidocaine and magnesium increased survival, neurologic outcome and cardiac function after prolonged cardiac arrest treated with ECLS. Moreover it improved cardioprotection through activation of the pro-survival kinases Akt and ERK1/2.

Abstract 16333: Racial Differences in Pressure-volume Relationships in Val122Ile Associated Cardiac Amyloidosis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Jaya Batra ◽  
iacopo olivotto ◽  
Mathew S Maurer
Keyword(s):  
Racial Differences ◽  
Cardiac Amyloidosis ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Disease Phenotype ◽  
Cardiac Chamber ◽  
Volume Relationship ◽  
Pressure Volume Relationship ◽  
White Patients

Background: Transthyretin cardiac amyloidosis (ATTR-CA) is the leading cause of restrictive cardiomyopathy in older adults. The valine-to-isoleucine substitution (Val122Ile) is the most common inherited variant in the U.S., primarily affecting patients of Afro-Caribbean descent. This variant has also been identified in white individuals in Northern Italy who present with a similar disease phenotype. It is unknown whether there are between-race differences in cardiac chamber function at diagnosis of Val122Ile associated ATTR-CA. Methods: In this retrospective study of 70 patients from two amyloid centers with Val122Ile associated ATTR-CA diagnosed over two decades, clinical and echocardiographic features at diagnosis were compared between races. Cardiac chamber performance was compared using noninvasive, single beat pressure-volume analysis. Results: Average age at diagnosis was 72 years. Compared to white patients (n=17), black individuals (n=53) had lower systolic blood pressure (110 vs. 131 mmHg , p<0.001), reduced pulse pressure (41 vs. 58 mmHg, p<0.001), and impaired renal function (eGFR 46 vs. 67 mL/min/1.73m 2 , p<0.001) at the time of diagnosis. End-systolic pressure-volume relationship (2.3 vs. 1.9 mmHg/mL, p = 0.88), and arterial elastance (3.0 vs. 3.0 mmHg/mL, p = 1.0) were similar between groups (Panel A). Black patients had an end-diastolic pressure-volume relationship shifted upward and leftward relative to white patients, indicating reduced left ventricular capacity. Accordingly, pressure-volume area at a left ventricular end-diastolic pressure of 30 mmHg was lower in black compared to white individuals (8,415 vs. 11,538 mmHg*mL, p = 0.012, Panel B). Conclusion: Despite presenting at a similar age to white patients, black individuals with Val122Ile associated ATTR-CA have a greater degree of cardiac remodeling which drives reduced overall chamber function. These findings suggest a more aggressive disease phenotype.

GH-releasing peptides improve cardiac dysfunction and cachexia and suppress stress-related hormones and cardiomyocyte apoptosis in rats with heart failure

2005 ◽  
Vol 289 (4) ◽  
pp. H1643-H1651 ◽  
Author(s):  
Xiang-Bin Xu ◽  
Jin-Jiang Pang ◽  
Ji-Min Cao ◽  
Chao Ni ◽  
Rong-Kun Xu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Pressure Overload ◽  
Chronic Administration ◽  
Posterior Wall ◽  
Left Ventricular ◽  
Cardiomyocyte Apoptosis ◽  
Lv Function ◽  
Cardiac Cachexia

Growth hormone (GH)-releasing peptides (GHRP), a class of synthetic peptidyl GH secretagogues, have been reported to exert a cardioprotective effect on cardiac ischemia. However, whether GHRP have a beneficial effect on chronic heart failure (CHF) is unclear, and the present work aims to clarify this issue. At 9 wk after pressure-overload CHF was created by abdominal aortic banding in rats, one of four variants of GHRP (GHRP-1, -2, and -6 and hexarelin, 100 μg/kg) or saline was injected subcutaneously twice a day for 3 wk. Echocardiography and cardiac catheterization were performed to monitor cardiac function and obtain blood samples for hormone assay. GHRP treatment significantly improved left ventricular (LV) function and remodeling in CHF rats, as indicated by increased LV ejection fraction, LV end-systolic pressure, and diastolic posterior wall thickness and decreased LV end-diastolic pressure and LV end-diastolic dimension. GHRP also significantly alleviated development of cardiac cachexia, as shown by increases in body weight and tibial length in CHF rats. Plasma CA, renin, ANG II, aldosterone, endothelin-1, and atrial natriuretic peptide were significantly elevated in CHF rats but were significantly decreased in GHRP-treated CHF rats. GHRP suppressed cardiomyocyte apoptosis and increased cardiac GH secretagogue receptor mRNA expression in CHF rats. GHRP also decreased myocardial creatine kinase release in hypophysectomized rats subjected to acute myocardial ischemia. We conclude that chronic administration of GHRP alleviates LV dysfunction, pathological remodeling, and cardiac cachexia in CHF rats, at least in part by suppressing stress-induced neurohormonal activations and cardiomyocyte apoptosis.

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