Evolution of the electrocardiographic changes in patients with hypertrophic cardiomyopathy

Abstract

In 75 patients with hypertrophic cardiomopathy (HCM) followed for a mean period of 5.5 years (range 2‐20 years), evolution of the electrocardiographic (EKG) changes was assessed. Progression of EKG abnormalities occurred in 35 patients (47%). It was manifested by an increase in precordial QRS voltage in 33 patients, development of new P‐wave mitral in 11 patients, and development or disappearance of pathologic Q waves in 14 patients. With follow‐up times >5 years, 5‐8 years, and >8 years, EKG progression was present in 27, 41, and 80% of patients, respectively. Age <30 years at the beginning of study and left ventricular outflow obstruction predisposed to EKG progression within 5‐8 years. Patients with progressive EKG changes were more prone to experience clinical deterioration than those without EKG progression (63 vs. 15%, p<0.001). With chronic verapamil administration, progression of EKG abnormalities occurred insignificantly less often than with propranolol treatment (35 vs. 64%, p=0.20). It is concluded that with long‐term follow‐up, HCM tends to progress in a significant proportion of adult patients. Copyright © 1991 Wiley Periodicals, Inc.