Abstract 15322: Echocardiographic Estimation of Left Ventricular Filling Pressures and of the Isovolumic Time Constant of Relaxation Validated by an Implantable Pressure Sensor
Background: Noninvasive assessment of left ventricular (LV) diastolic function in patients with heart failure is essential for clinical decision making and adjustment of therapy. Aims of the study were: (1) to evaluate the accuracy of echocardiographic assessment of LV mean diastolic (LVMDP) and end-diastolic (LVEDP) pressures, and (2) to provide a noninvasive estimation of the load-independent isovolumic time constant of relaxation Tau, validating echocardiographic parameters against intraventricular pressure measurements from an implantable manometer.
Methods: Permanent LV pressure sensors (Transoma LVP-1000) were implanted in patients with very poor LV function, who underwent cardiac bypass or valve surgery. Echocardiography with tissue Doppler imaging was performed at follow-up concomitantly with LV pressure readings from Transoma device (n = 21 simultaneous measurements). Diastolic Doppler parameters (mitral E velocity, -dp/dt calculated from the deceleration slope of mitral regurgitation, isovolumic relaxation period IVRT, propagation velocity of early mitral inflow at color Doppler Epropag, difference in duration PVr-A between pulmonary venous reverse flow and mitral A wave and mitral annulus velocities E' and A') were used for estimation of Tau, LVEDP and LVMDP.
Results: As shown in the Figure, early mitral velocity E enabled a slightly better estimation of LVMDP compared to the indices E/E′ and E/A. Values of E > 85 cm/s predicted LVMDP > 12 mmHg with a sensitivity of 83% and specificity of 87%, respectively. E/A was the best predictor of elevated LVEDP (E/A > 1: 71% sensitivity and 83% specificity for LVEDP > 15 mmHg). A quick assessment using Doppler parameters of mitral inflow could also provide a good estimation of Tau.
Conclusions: In patients with advanced systolic heart failure conventional Doppler parameters of mitral inflow proved to be robust enough for noninvasive assessment of the relaxation time constant and of LV filling pressures.
- © 2010 by American Heart Association, Inc.