ANALYSIS OF PERIOPERATIVE VENTRICULAR ARRHYTHMIAS IN VALVULAR HEART DISEASES BY HOLTER ECG RECORDING

Seventy-one consecutive patients undergoing cardiac surgery for acquired valvular diseases were analyzed to determine the incidence of and the predisposing factors to postoperative ventricular arrhythmias. We recorded the Holter ECGS before (pre-op), and within 24h (op-day) and 4 to 10 weeks after operation (post-op) and determined the frequency of ventricular arrhythmias and the degree according to the Lown grade. The relationship between the op-day ventricular arrhythmias and clinical, hemodynamic, operative or postoperative variables was examined. The operation included mitral valve replacement or open mitral commissurotomy (49 patients, group M), aortic valve replacement (12 patients, group A) and a combined mitral and aortic operation (10 patients. group A+M). In all groups, the frequency and the degree of ventricular arrhythmias increased at the op-day and decreased at the post-op period approximately to the pre-op level. The frequency and Lown grade of the 3 groups were similar in each of the pre-op, the op-day and the post-op periods. The frequency and Lown grade of the op-day ventricular arrhythmias increased with increases in the arrhythmia frequency and Lown grade at the pre-op period, and in patients with left ventricular (LV) dysfunction at the post-op period, as evidence by an increased LV volume and decreased ejection fraction on echocardiograms. Furthermore, the frequency of ventricular premature contractions in the op-day was significantly less when a cardioplegia solution containing magnesium was used than in the case of a cardioplegia solution without magnesium. The op-day ventricular arrhythmias showed no significant relation to extracorporeal ciuculation time, aortic cross-clamping time, the antiarrhythmic drugs used and the op-day serum levels of K and CK-MB.