Influence of Patern and Degree of Left Ventricular Hypertrophy on Cardiac Arrhythmias

A large number of clinical and epidemiological studies [1,2] have reported a correlation between the mass increase of the left ventricle (LV) and the risk of disease or death. The prevalence of left ventricular hypertrophy (LVH) in patients with essential hypertension may be as high as 40% (12%-70%) [3]. It has been suggested [4] that in patients with LVH sudden death may be associated with an increased number of ventricular extrasystoles (VPB), which is frequently observed in this population. In effect, a review by Lombardi et al. [5] indicated that nonsustained ventricular arrhythmias are an independent predictor of cardiac death in hypertensive patients. Most frequently it concerns concentric hypertrophy with no enlargement of ventricular cavities, interpreted by multiplication of sarcomeras in a parallel arrangement. This type of hypertrophy is characterised by increased mass and increased relative wall thickness. In a smaller number of hypertensives LVH is initially eccentric, with a multiplication of sarcomeras in sequence in the process of which enlargement of the ventricular cavity is prevalent and thickening of the wall is only proportional or less marked. Although many hypertensive patients develop isolated septum hypertrophy, data on the structure and function of the myocardium and arrhythmias in hypertensive patients with this type of LVH are limited [6]. It would appear that concentric hypertrophy carries the greatest and eccentric hypertrophy a moderate risk of cardiovascular (CV) events [7]. Published data regarding arrhythmias are still conflicting and unconvincing [6,8]. It is unclear whether the greatest risk of CV events in the concentric type is due to arrhythmias or something else (ishaemia for inst.). According to some authors [9] the correlation between left ventricular mass (LVM) and ventricular arrhythmias is graded and permanent. Arrhythmias described in hypertensive patients with LVH are usually single premature ventricular contractions, frequently bigeminal or multiform, and more rarely ventricular tachycardia. [10]