STUDY OF LATE POTENTIALS AND VENTRICULAR ARRHYTHMIAS IN HYPERTENSIVE PATIENTS WITH NORMAL ELECTROCARDIOGRAMS

Introduction: Although an increase in the occurrence of ventricular ar rhythmias has been observed in hypertensive patients, some basic quest ions remain unresolved regarding the prevalence and the pathophysiolog y of these arrhythmias. The basic aims of this study were as follows: (1) to examine the incidence and severity of ventricular arrhythmias i n a substantial number of hypertensive patients without electrocardiog raphic indications of hypertrophy; and (2) to examine the correlation between late potentials, hypertrophy, and ventricular arrhythmias in t hese patients. Materials and Methods: We studied 78 consecutive patien ts (31 men, 47 women), aged 60.5 +/- 7.8 years, with a history of hype rtension but a normal electrocardiogram. All patients had an echocardi ographic study, 24-hour ambulatory monitoring, exercise test, and sign al-averaged electrocardiograrm. The latter was analyzed using a 40- to 250-Hz filter and with a noise level less than or equal to 0.3 mu V R esults: Of the 78 patients studied, 21 (26.9%) had severe ventricular arrhythmias, while 57 (73.1%) had either no ventricular ectopics or sp oradic isolated ventricular extrasystoles. Left ventricular hypertroph y, defined by echocardiography, was found in 58 patients (74.3%), of w hich 16 (27.58%) had severe ventricular arrhythmias. Five (25%) of the 20 patients without hypertrophy also had severe ventricular arrhythmi as (P = NS). Ventricular late potentials were recorded in 19 (24.5%) o f the 78 patients. Of these, 11 (57.89%) had severe arrhythmias, while of the 59 patients without late potentials 10 (16.94%) had severe ven tricular ectopic activity. Conclusions: In hypertensive patients witho ut electrocardiographic signs of hypertrophy, the higher prevalence of ventricular arrhythmias does not appear to be related to left ventric ular hypertrophy but is correlated with the existence of ventricular l ate potentials.