071: Assessment of diastolic function from velocity-encoded cardiac magnetic resonance data in patients with hypertrophic cardiomyopathy

Abstract

To assess the value of velocity and flow rate-related parameters obtained by cardiac magnetic resonance (CMR) for evaluation of left ventricular (LV) diastolic function (DF) in patients (pts) with hypertrophic cardiomyopathy (HCM). CMR was performed in 26 HCM pts and 24 healthy volunteers (HV) matched for age, gender, body surface area (BSA) and blood pressure. DF parameters were obtained using a semi-automated software enabling extraction of transmitral flow, including transmitral Ef and Af flow rate peaks, isovolumetric relaxation time (IVRT) and early peak diastolic longitudinal myocardial velocity E’ obtained using 2D phase contrast-CMR. LV mass and volumes and left atrial (LA) volumes were measured from cine CMR images. Mean age was 47.0±20.2 years in HCM pts and 47.5±16.1 in HV (p=NS). LV mass, mass/end-diastolic volume and LA volumes were increased in HCM pts (table). Late gadolinium enhancement was found in 20 HCM pts. While there was no significant difference in Ef/Af, myocardial longitudinal velocity E’ and LA emptying fraction were markedly lower in HCM pts. Furthermore, E/E’ ratio and E wave deceleration time (DT) were higher in HCM pts. There was a linear relationship between increased LV mass and increased LA volumes (p<0.001), IVRT (p=0.003), DT (p=0.002), E/E’ (p=0.002) and decreased E’ (p=0.003) independent of age, gender and BSA. Comparison of HCM pts with HV by CMR showed altered LVDF and increased LA volumes related to increased LV mass. Assessment of DF may be considered for routine comprehensive evaluation of LV function in HCM. Table – Results. Normal (n=24) HCM (n=26) p LV mass (g) 132.0 (32.8) 217.3 (92.0) 0.0001 LV mass/EDV (g/ml) 1.0 (0.3) 1.5 (0.5) 0.0001 E wave DT (ms) 202 (41) 247 (63) 0.005 IVRT (ms) 86 (32) 126 (78) <0.0001 E’ (cm/s) 8.8 (4.6) 3.1 (1.9) <0.0001 E/E’ 7.8 (4.4) 31.4 (22.1) <0.0001 LA EDV (ml) 62.9 (16.4) 85.3 (44.8) 0.03 LA ESV (ml) 31.6 (9.4) 51.4 (30.0) 0.004 LA emptying fraction (%) 50.1 (7.7) 40.0 (11.0) 0.0007