Evaluate Energy Loss Changes within Left Ventricle in 4 Patients with Obstructive Hypertrophic Cardiomyopathy after Modified Morrow Procedure Using Vector Flow Mapping

Abstract

To evaluate the changes of left ventricle energy loss (EL) in patients with obstructive hypertrophic cardiomypoathy (HOCM) after modified morrow procedure using vector flow mapping (VFM), and to explore its clinical value in evaluating the operation effect. Retrospectively analyzed the data from four patients with HOCM treated by modified morrow procedure. Measure the echocardiographic parameters before and after surgery, respectively, and EL of LV was analyzed frame by frame using color Doppler images of a standard apical three-chamber dynamic view on an offline VFM workstation. The average EL of LV isovolumetric contraction phase, ejection phase, isovolumetric relaxation phase and filling phase were calculated. Compared with preoperative condition, 1). echocardiographic parameters: the left ventricular outflow tract (LVOT) diameter and left ventricular end-systolic volume were obviously increased, the LVOT gradient and the thickness of ventricular septum were significantly decreased, the differences were obviously significant (P < 0.05). Systolic anterior motion (SAM) disappeared in all cases. 2). EL value changes: During isovolumetric contraction phase and filling phase, averaged EL values were markedly increased in patient 1 and patient 2 and markedly decreased in patient 4, in patient 3 it was increased a little. During isovolumetric relaxation phase and ejection phase, averaged EL values were markedly increased in patient 1 and patient 2 and markedly decreased in patient 3 and patient 4. As a whole the variation trend was that the EL values in patient 1 and patient 2 increased greatly, but decreased greatly in patient 3 and patient 4. After modified Morrow procedure, even the normal conditions and echocardiographic parameters were significantly improved in HOCM patients, an increased energy loss may lead to worse outcomes, EL might be an new index for precise and quantitative assessment of intracardiac flow dynamics under different pathophysiology conditions.