[Arterial hypertension, left ventricular hypertrophy and arrhythmias]

Abstract

Arterial hypertension is the most common cause of chronic pressure overload of the left ventricle. Electrocardiographic and echocardiographic signs of left ventricular hypertrophy in hypertensive patients are associated with an increased cardiovascular mortality and incidence of sudden death habitually due to ventricular arrhythmias. The significance of a normal increase in systolic blood pressure during exercise in persons without evident resting hypertension is uncertain. M-mode and 2D echocardiography, 24-hour continuous ambulatory electrocardiographic (Holter), exercise testing and 24-hour ambulatory blood pressure monitoring (ABPM) were performed on 22 normotensive patients (group I); 25 normotensives with exaggerated blood pressure response to exercise (greater than 220 mmHg) (group II) and 33 hypertensive patients (group III). None was taking cardioactive drugs. Left ventricular hypertrophy (LVH) was found on one patient of group I (4.5%), 13 of group II (52%) and 20 of group III (61%). Left ventricular mass index (LVMI) was linearly correlated with maximum exercise blood pressure (group I: r2 = 0.518, p less than 0.0002; group II: r2 = 0.098, NS; group III: r2 = 0.407, p less than 0.0001) with 24-hour systolic pressure overload (ABPM) (group I: r2 = 0.848, p less than 0.0001; group II: r2 = 0.705, p less than 0.0001; group III: r2 = 0.839, p less than 0.0001) and 24-hour diastolic pressure overload (ABPM) (group I: r2 = 0.612, p less than 0.0001; group II: r2 = 0.815, p less than 0.0001; group III: r2 = 0.807, p less than 0.0001) within each group but not between different groups. The hypertensive subjects (group III) had a higher average heart rate (p less than 0.0001) more supraventricular premature (p less than 0.0001) and ventricular premature (p less than 0.0001) beats than the normotensive (group I) and normotensive patients with abnormal increases in systolic blood pressure response to exercise (group II) (p less than 0.0001) (NS) and (p less than 0.0002), respectively. LVMI was linearly correlated with ventricular premature beats (group I: r2 = 0.072, NS; group II: r2 = 0.823, p less than 0.0001; group III: r2 = 0.691, p less than 0.0001). Frequent and complex ventricular arrhythmias were more common in patients with LVH normotensives or hypertensives than without LVI (p less than 0.0001) and the age increases their severity. We conclude that normotensives with hypertensive response to exercise have similar incidence of LVI; if those patients develop sustained hypertension, LVI was previous to arterial hypertension. There are two types of hypertrophy: secondary hypertrophy is linked to the high afterload and vasoconstriction typical in hypertension.(ABSTRACT TRUNCATED AT 400 WORDS)