Regression of myocardial hypertrophy: Electrocardiographic-echocardiographic correlations after aortic valve replacement in patients with chronic aortic regurgitation

Abstract

Serial electrocardiographic and echocardiographic left ventricular (LV) studies were performed in 21 patients before and after aortic valve replacement (AVR) for chronic aortic regurgitation. Changes in voltage (SV1 + RV 5-6) after AVR were assessed and evaluated relative to changes in LV mass. Muscle cross-sectional area (CSA) derived from echocardiographic dimension and wall thickness data was used as an index of LV muscle mass (LV hypertrophy > 10 cm2/m2). In 15 patients, voltage was reduced after AVR: Seven had normal voltage (48 ± 17 mm to 25 ± 6 mm, p<0.005) and eight still had increased voltage (61±17 mm to 40±4 mm, p<0.01). Patients with normal voltage had complete regression of hypertrophy by echocardiography (CSA decreased from 13 ± 3 cm2/m2 to 9 ± 1 cm2/m2, p<0.025), while those who had persistently increased voltage had incomplete regression (15 ± 2 cm2/m2 to 11 ± 2 cm2/m2, p<0.001). Reduction in voltage generally occurred in the first 6 months after AVR. Three patients with unchanged voltage had evidence of paraprosthetic regurgitation and minimal change in CSA. Three other patients with persistent LV enlargement without paraprosthetic regurgitation had a severe intraventricular conduction delay. Data from 59 electrocardiographic-echocardiographic studies before and after AVR revealed a strong correlation (r = 0.81) between voltage and muscle CSA. After surgical correction of chronic aortic regurgitation, regression of LV hypertrophy can be assessed by serial electrocardiographic studies. These ECG data identify patients with complete, incomplete or no regression of LV hypertrophy.