Noninvasive estimation of left ventricular compliance using three-dimensional echocardiography

Background: Left ventricular (LV) compliance is an important determinant of LV function and can be affected by a variety of cardiovascular conditions. In particular, diastolic dysfunction is associated with altered LV compliance. However, the evaluation of LV compliance is complex. Although the end-diastolic pressure-volume relationship (EDPVR) allows a direct, accurate evaluation of LV compliance, it requires invasive measurements. The aim of this study was to test the feasibility of noninvasive estimation of the EDPVR as a tool to evaluate LV compliance using three-dimensional echocardiography. Methods: Sixty-eight subjects were studied, including 23 normal controls, 22 patients with increased LV compliance due to dilated cardiomyopathy, and 23 patients with reduced LV compliance secondary to isolated diastolic dysfunction as defined using current American Society of Echocardiography guidelines. The EDPVR was calculated for each subject using a nonlinear model with echocardiographic estimates of end-diastolic pressure and volume. For both the isolated diastolic dysfunction and dilated cardiomyopathy groups, predicted end-diastolic volumes at predetermined pressure values (5, 10, 20, and 30 mm Hg) were compared with values in normal controls. Results: Compared with controls, noninvasive estimates of the EDPVR resulted in predicted end-diastolic volumes that were lower in the isolated diastolic dysfunction group and higher in the dilated cardiomyopathy group (P <.0001 for all four pressure levels). In addition, a stepwise trend of decreased compliance was noted for the different grades of diastolic dysfunction. Conclusions: This is the first study to demonstrate the feasibility of noninvasive estimation of the LV EDPVR and its ability to differentiate normal from abnormal LV compliance using three-dimensional echocardiography.