VENTRICULAR ARRHYTHMIAS IN HYPERTENSION - IN WHICH PATIENTS DO THEY OCCUR

Objective: It has been suggested that the increased incidence of sudde n death in hypertensive patients, particularly those with left ventric ular hypertrophy, may be causally related to the increased number and complexity of ventricular arrhythmias that have been demonstrated in t hese patients. The objective of the present study was to assess some o f the factors which might be responsible for these arrhythmias. Subjec ts and methods: One hundred and three untreated subjects were divided into four groups on the basis of blood pressure and echocardiographic measurements: hypertensive patients with left ventricular hypertrophy (n = 38), hypertensive patients without left ventricular hypertrophy ( n = 16), patients with borderline or white-coat hypertension (n = 26) and normotensive subjects (n = 23). Each subject underwent two-dimensi onal and Doppler echocardiography, 12-lead electrocardiogram examinati on, 12-lead electrocardiogram exercise stress testing, 24-h ambulatory blood pressure monitoring and 24-h Holter monitoring. A further 17 hy pertensive patients with left ventricular hypertrophy who were on long -term antihypertensive therapy were also investigated in the same mann er and compared with untreated hypertensive patients with left ventric ular hypertrophy who were matched for age, sex and race. Results: Untr eated hypertensive patients, even with left ventricular hypertrophy, h ad a low prevalence of frequent or complex arrhythmias (seven out of 8 0 patients with Lown score 2+). In contrast, hypertensive patients wit h left ventricular hypertrophy on long-term antihypertensive therapy h ad a significantly greater prevalence of complex arrhythmias than untr eated patients with left ventricular hypertrophy (eight out of 17 trea ted patients compared with two out of 17 untreated patients with Lown score 2+). Conclusions: Hypertensive patients with left ventricular hy pertrophy who had received long-term antihypertensive therapy were fou nd to have a high prevalence of complex ventricular arrhythmias, which was in contrast to untreated hypertensive patients, even those with l eft ventricular hypertrophy. This may reflect the consequences on the left ventricle of long-term antihypertensive treatment. If complex ven tricular arrhythmias are implicated in the excess of sudden deaths in hypertensive patients, this might be an important factor.