Impact of left ventricular volume/mass ratio on diastolic function

AIMS: To assess the impact of left ventricular (LV) volume/mass ratio on diastolic function parameters in subjects with dilated cardiomyopathy (DCM) or hypertrophic cardiomyopathy (HCM) and healthy controls. METHODS AND RESULTS: We performed echocardiography in 44 healthy controls, 35 HCM subjects, 29 DCM subjects with narrow QRS complex (DCM-n), and 27 DCM subjects with wide QRS complex (DCM-w). Mitral annulus velocity (E(a)) and transmitral E-wave velocity were used to estimate time constant of isovolumic pressure decay (tau). LV flow propagation velocity (V(p)) and early intraventricular pressure gradient (IVPG) were derived from colour M-mode of LV inflow. We calculated LV twist and peak untwisting rate (UntwR) by speckle tracking. Mean LV volume/mass ratio was 0.34 +/- 0.09 mL/g in healthy controls, 0.15 +/- 0.06 mL/g in HCM, 0.6 +/- 0.2 mL/g in DCM-n, and 0.8 +/- 0.3 mL/g in DCM-w patients (P < 0.001 for all groups). Resting LV ejection fractions were 63 +/- 7, 64 +/- 8, 31 +/- 8, and 26 +/- 8%, respectively (P < 0.01 vs. controls for DCM groups). In a multivariate analysis, LV volume/mass ratio remained a strong independent predictor of V(p) (P < 0.001), IVPG (P = 0.009), and UntwR (P < 0.001) but not for E(a) (P = 0.25). CONCLUSION: LV volume/mass ratio had influences on diastolic function parameters independent of intrinsic diastolic function and filling pressures. It should be considered when assessing patients suspected of LV diastolic dysfunction.