Impact of left ventricular hypertrophy on ventricular arrhythmias in the absence of coronary artery disease

Left ventricular hypertrophy has a grave prognosis. Ventricular arrhythmias may account for a large portion of this poor prognosis, but the contribution of coronary artery disease has not been excluded. The occurrence of ventricular arrhythmias was investigated by 24 h ambulatory electrocardiographic (ECG) monitoring in 49 hypertensive patients who had normal findings on coronary arteriography. The presence of left ventricular hypertrophy was assessed by both ECG and echocardiography. The frequency and complexity of ventricular arrhythmias were significantly related to the presence of left ventricular hypertrophy whether it was defined by wall thickness (interventricular septum or posterior wall greater than or equal to 1.2 cm) or by left ventricular mass indexed to height (left ventricular mass/height greater than or equal to 163 g/m in men and greater than or equal to 121 g/m in women). The relation between left ventricular mass or wall thickness to ventricular arrhythmia was graded and continuous; for every 1 mm increase in the thickness of interventricular septum or posterior wall there was an associated two- to threefold increase, respectively, in the occurrence and complexity of ventricular arrhythmias. In conclusion, left ventricular hypertrophy is associated with an increase in the frequency and complexity of ventricular arrhythmias in the absence of coronary artery disease, and the relation is graded and continuous.