Assessment of Diastolic Function in Hypertrophic Cardiomyopathy by Computed Tomography-Derived Analysis of Left Ventricular Filling

OBJECTIVES Hypertrophic cardiomyopathy (HCM) is characterized by diastolic dysfunction, which is difficult to assess by noninvasive methods. We hypothesized that measurement of simultaneous left ventricular (LV) and left atrial (LA) volume changes by cardiac computed tomography would be useful in the assessment of diastolic function in HCM. METHODS We studied 21 patients with HCM and 21 age-matched controls. The LA and LV volumes were calculated and early and late diastolic volume changes derived. RESULTS The HCM patients had significantly larger LA volumes and reduced LA total emptying fraction (30 ± 7% vs 42 ± 6%; P < 0.0001). Conduit volume was increased (30 ± 6 vs 22 ± 4 mL/m; P < 0.0001) and contributed a significantly higher proportion of total LV diastolic filling, suggesting that passive filling of the LV compensates for LA dysfunction, but at the expense of increased pulmonary filling pressure. CONCLUSIONS This study suggests that simultaneous depiction of computed tomography-derived LV and LA volume changes can characterize diastolic dysfunction in HCM.