ABSTRACT
Objective To evaluate left ventricular(LV) twist and untwist using velocity vector imaging(VVI) in patients with apical hypertrophic cardiomyopathy (ApHCM). Methods Twenty-three patients diagnosed with ApHCM were consecutively enrolled and compared with normal controls. After a standard echocardiographic examination, parasternal basal and apical short-axis planes were scanned to quantify LV rotations,twist and LV untwist using VVI. Results Compared with the normal controls, the rotation and rotaional velocity of apical subendocardial myocardium were markedly decreased in ApHCM patients during the period of systole ( P＜0.05) ,but the decreases in basal planes were not significant. As a consequence,LV twist was significantly lower in ApHCM patients (P＜ 0.05). Compared to normal controls,the velocity of LV untwisting was also significantly decreased in ApHCM patients ( P＜0.05).Conclusions The twist and untwist of LV subendocardial myocardium were decreased in ApHCM patients.VVI is a useful method to assess the characteristics of LV twist and untwist in ApHCM patients.