Left ventricular geometry during unloading and the end-systolic pressure volume relationship: Measurement with a modified real-time MRI-based method in normal sheep

The end-systolic pressure-volume relationship is regarded as a useful index for assessing the contractile state of the heart. However, the need for preload alterations has been a serious limitation to its clinical applications, and there have been numerous attempts to develop a method for calculating contractility based on one single pressure-volume loop. We have evaluated four of these methods. Pressure-volume data were obtained by combined pressure and conductance catheters in 37 pigs. All four methods were applied to 88 steady-state pressure-volume files, including eight files sampled during dopamine infusions. Estimates of single-beat contractility (elastance) were compared with preload-varied multiple-beat elastance [ E es(MB)]. All methods had a low average bias (−0.3 to 0.5 mmHg/ml) but limits of agreement (±2 SD) were unacceptably high (±2.6 to ±3.8 mmHg/ml). In the dopamine group, E es(MB) showed an increase of 1.7 ± 0.8 mmHg/ml (mean ± SD) compared with baseline ( P < 0.001). None of the single-beat methods predicted this increase in contractility. It is therefore doubtful whether any of the methods allow for single-beat assessment of contractility.

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Left ventricular outflow tract mean systolic acceleration as a surrogatefor the slope of the left ventricular end-systolic pressure-volume relationship

Journal of the American College of Cardiology ◽

10.1016/s0735-1097(02)02138-1 ◽

2002 ◽

Vol 40 (7) ◽

pp. 1320-1327 ◽

Cited By ~ 31

Author(s):

Fabrice Bauer ◽

Michael Jones ◽

Takahiro Shiota ◽

Michael S Firstenberg ◽

Jian Xin Qin ◽

...

Keyword(s):

Left Ventricular Outflow Tract ◽

Systolic Pressure ◽

Ventricular Outflow Tract ◽

Left Ventricular ◽

Outflow Tract ◽

Volume Relationship ◽

Left Ventricular Outflow ◽

Pressure Volume Relationship

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Human left ventricular end-systolic pressure-volume relationship in a cylinder model.

Japanese Heart Journal ◽

10.1536/ihj.29.689 ◽

1988 ◽

Vol 29 (5) ◽

pp. 689-707 ◽

Cited By ~ 2

Author(s):

Kouichi TAKEDA ◽

Takahiko SHIMIZU ◽

Hideo YAMAMOTO ◽

Shigeru YAGI

Keyword(s):

Systolic Pressure ◽

Left Ventricular ◽

Cylinder Model ◽

Volume Relationship ◽

Pressure Volume Relationship

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A New Non-Invasive Method for Assessing the Intrinsic Active Strength of Human Left Ventricular Tissue

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176314 ◽

2007 ◽

Author(s):

Tom E. Claessens ◽

Ernst R. Rietzschel ◽

Marc L. De Buyzere ◽

Dirk De Bacquer ◽

Guy De Backer ◽

...

Keyword(s):

Systolic Pressure ◽

Left Ventricular ◽

Contractile State ◽

Non Invasive ◽

Left Ventricular Tissue ◽

Ventricular Tissue ◽

Volume Relationship ◽

Invasive Method ◽

Pressure Volume Relationship ◽

Human Left Ventricle

The contractile state of the human left ventricle (LV) is often assessed by its end-systolic elastance (Ees) [1]. This index is calculated as the slope of the linear end-systolic pressure-volume relationship (ESPVR), which connects the upper left corners of pressure-volume loops obtained under various loading conditions (figure 1).

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

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1989.256.1.h56 ◽

1989 ◽

Vol 256 (1) ◽

pp. H56-H65 ◽

Cited By ~ 2

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.

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

Circulation ◽

10.1161/circ.142.suppl_3.16333 ◽

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.

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Interrelation between end-systolic pressure-volume and pressure-wall thickness relations

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1988.255.3.h679 ◽

1988 ◽

Vol 255 (3) ◽

pp. H679-H684

Author(s):

J. D. Schipke ◽

J. Alexander ◽

Y. Harasawa ◽

R. Schulz ◽

D. Burkhoff

Keyword(s):

Pressure Range ◽

Systolic Pressure ◽

Left Ventricular ◽

Ventricular Contractility ◽

Ventricular Systolic Pressure ◽

Straight Line ◽

Volume Relationship ◽

Pressure Volume Relationship ◽

Left Ventricular Systolic Pressure

We predicted the shape of the end-systolic pressure-thickness relationship (ESPTR) by modeling the left ventricle as thick-walled sphere. To test the validity of the predicted relationships, we then measured the ESPTR over wide volume ranges in seven isolated blood-perfused canine hearts. Both simulation and experiments demonstrated that the ESPTR is curvilinear. However, within a physiological left ventricular systolic pressure range (80–150 mmHg), the ESPTR was described reasonably well by a straight line. Within that pressure range, changes in left ventricular contractile state, assessed by slope changes of the end-systolic pressure-volume relationship, were associated with almost parallel shifts in the ESPTR. In contrast, in a low pressure range (less than 80 mmHg), contractility changes were associated with slope changes of the ESPTR. We conclude that, in general, there are limitations in the application of ESPTR for assessing left ventricular contractility, but if the limitations are recognized and accounted for, then the ESPTR may be useful for assessing contractility changes in vivo.

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