Novel echocardiographic method to assess left ventricular chamber stiffness and elevated end-diastolic pressure based on time-velocity integral measurements of pulmonary venous and transmitral flows

Aims The detection of increased left ventricular (LV) chamber stiffness may play an important role in assessing cardiac patients with potential but not overt heart failure. A non-invasive method to estimate it is not established. We investigated whether the echocardiographic backward/forward flow volume ratio from the left atrium (LA) during atrial contraction reflects the LV chamber stiffness. Methods and results We studied 62 patients who underwent cardiac catheterization and measured their left ventricular end-diastolic pressure (LVEDP) and pressure increase during atrial contraction (Delta Pa) from the LV pressure waveform. Using the echocardiographic biplane method of disks, we measured the LV volume change during atrial contraction indexed to the body surface area (Delta Va), and Delta Pa/Delta Va was calculated as a standard for the LV operating chamber stiffness. Using pulsed Doppler echocardiography, we measured the time-velocity integral (TVI) of the backward pulmonary venous (PV) flow during atrial contraction (I-PVA) and the ratio of I-PVA to the PV flow TVI throughout a cardiac cycle (F-PVA). We also measured the TVI of the atrial systolic forward transmitral flow (I-A) and the ratio of the I-A to the transmitral TVI during a cardiac cycle (F-A) and calculated I-PVA/I-A and F-PVA/F-A. IPVA/IA and F-PVA/F-A were well correlated with Delta Pa/Delta Va (r = 0.79 and r = 0.81) and LVEDP (r = 0.73 and r = 0.77). The areas under the ROC curve to discriminate LVEDP > 18mmHg were 0.90 for I-PVA/I-A and 0.93 for F-PVA/F-A. Conclusion The F-PVA/F-A, the backward/forward flow volume ratio from the LA during atrial contraction, is useful for noninvasive assessments of LV chamber stiffness and elevated LVEDP.