TY - JOUR
T1 - Relationship Between Ventricular Contractility and Early Diastolic Intraventricular Pressure Gradients
T2 - A Diastolic Link to Systolic Function
AU - Firstenberg, Michael S.
AU - Greenberg, Neil L.
AU - Garcia, Mario J.
AU - Thomas, James D.
N1 - Funding Information:
Supported in part by National Aeronautics Space Administration Grant NCC9-58 and NCC9-60, Houston, Texas, and National Institutes of Health Grant ROI HL56688-01A1, Bethesda, Maryland.
PY - 2008/5
Y1 - 2008/5
N2 - Background: Early diastolic intraventricular pressure gradient (IVPG), as derived by color M-mode echocardiography, has been proposed to correlate with left ventricular (LV) elastic recoil. However, any relationship to quantifiable indices of LV contractility is poorly defined. Methods: To relate IVPG with invasive and noninvasive indices of contractility, 6 closed-chest dogs each had a high-fidelity conductance catheter placed into the LV for continuous determination of end-diastolic pressures, volumes, +dP/dtmax, and the time constant of LV relaxation (tau) under baseline conditions and 4 different stages of β-receptor modulation. At each stage, IVPGs were determined from color M-mode echocardiography images. Doppler-derived strain rate (ε{lunate}′) and myocardial systolic myocardial velocities (Sm) were also measured. Emax was obtained from the slope of the end-systolic pressure-volume relationship during caval occlusion. Results of contractility indices were compared to IVPG with regression analysis. Results: IVPG ranged from 0.72 to 3.95 mm Hg whereas Emax ranged from 0.66 to 14.9 mm Hg/mL and end-systolic volume ranged from 1.9 to 59.7 mL. IVPG correlated with ε{lunate}′ (r = 0.71), Sm (r = 0.67), end-systolic volume (r = 0.53), and invasive indices (+dP/dtmax, r = 0.71, and Emax, r = 0.82). Conclusions: Early diastolic IVPGs are associated with LV contractility. These findings may explain the proposed mechanism in which potential energy stored during systole is released during diastole to provide for adequate ventricular filling, even under low filling pressures.
AB - Background: Early diastolic intraventricular pressure gradient (IVPG), as derived by color M-mode echocardiography, has been proposed to correlate with left ventricular (LV) elastic recoil. However, any relationship to quantifiable indices of LV contractility is poorly defined. Methods: To relate IVPG with invasive and noninvasive indices of contractility, 6 closed-chest dogs each had a high-fidelity conductance catheter placed into the LV for continuous determination of end-diastolic pressures, volumes, +dP/dtmax, and the time constant of LV relaxation (tau) under baseline conditions and 4 different stages of β-receptor modulation. At each stage, IVPGs were determined from color M-mode echocardiography images. Doppler-derived strain rate (ε{lunate}′) and myocardial systolic myocardial velocities (Sm) were also measured. Emax was obtained from the slope of the end-systolic pressure-volume relationship during caval occlusion. Results of contractility indices were compared to IVPG with regression analysis. Results: IVPG ranged from 0.72 to 3.95 mm Hg whereas Emax ranged from 0.66 to 14.9 mm Hg/mL and end-systolic volume ranged from 1.9 to 59.7 mL. IVPG correlated with ε{lunate}′ (r = 0.71), Sm (r = 0.67), end-systolic volume (r = 0.53), and invasive indices (+dP/dtmax, r = 0.71, and Emax, r = 0.82). Conclusions: Early diastolic IVPGs are associated with LV contractility. These findings may explain the proposed mechanism in which potential energy stored during systole is released during diastole to provide for adequate ventricular filling, even under low filling pressures.
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U2 - 10.1016/j.echo.2007.08.023
DO - 10.1016/j.echo.2007.08.023
M3 - Article
C2 - 17928198
AN - SCOPUS:43049136542
SN - 0894-7317
VL - 21
SP - 501
EP - 506
JO - Journal of the American Society of Echocardiography
JF - Journal of the American Society of Echocardiography
IS - 5
ER -