ECG-Gated Cardiac Scan and Echocardiographic Assessments of Left Ventricular Hypertrophy

Abstract

Serial changes of left ventricular (LV) mass and LV function were evaluated in nine patients with essential hypertension and LV hypertrophy (LVH) after administration of diltiazem (180 mg/day). LV mass and LV function were determined at baseline and at 6 months of therapy by electrocardiogram-gated cardiac CT (ECG-gated CCT) scanning and two-dimensional-guided M-mode echocardiography. At baseline measurements, ECG-gated cardiac scanning clearly showed LVH in two patients in whom no LVH was observed by echocardiography. The systolic and diastolic blood pressures were reduced significantly after 6 months of drug therapy (189-156 mm Hg; p less than 0.01, 111-96 mm Hg; p less than 0.01, respectively). Sequential ECG-gated cardiac scanning revealed a marked reduction in thickness of the interventricular septum (IVS), LV anterior wall (AW), and LV posterior wall (PW) (15.0-12.1 mm; p less than 0.01, 12.5-9.7 mm; p less than 0.01, 10.7-8.3 mm; p less than 0.05, respectively). Simultaneous echocardiographic measurements revealed a reduction in LV mass in six of these patients and a significant reduction in thickness of the IVS (12.1-11.0 mm; p less than 0.05). ECG-gated cardiac scanning demonstrated significant reductions in the thickness of the LVAW, which are difficult to detect by echocardiography. Diltiazem had no effect on the ejection fraction (EF) measured by both methods. In conclusion, ECG-gated cardiac scanning allowed more accurate diagnosis and quantitation of LVH than conventional echocardiography, and LVH in patients with essential hypertension could be reversed by the administration of diltiazem.