225 Long-term prognosis of ventricular tachycardia without apparent heart disease

Abstract

Cardiac MRI can now identify heart diseases which were not apparent with conventional techniques. The prognosis of a ventricular tachycardia (VT) depends on the presence or not of heart disease. Only VT in patients (pts) without heart disease (HD) seems benign. The purpose of the study was to evaluate the long-term prognosis of pts with spontaneous VT and without apparent HD at conventional methods. During the last 30 years, 820 pts were admitted for a sustained VT. ECG, signal averaged ECG, Holter monitoring, exercise testing, echocardiography, right angiography in VT with left bundle branch block (LBBB) pattern, coronary angiography after 40 years and electrophysiological study were indicated. 81 pts (10%), aged from 11 to 75 years (46±18), 46 men, 35 women had normal echocardiogram and hemodynamic study. VT had a LBBB pattern (51), right bundle branch block (RBBB) pattern (26) or both patterns (4). VT developed at exercise testing in 15 pts and was inducible or occurred with isoproterenol in 61 pts (75%). Pts were followed from 1 to 20 years (mean 8±6); 3 were lost of view. Beta blockers and/or antiarrhythmic drugs were initially prescribed. Defibrillator was implanted in 4 pts, 2 of them for arrhythmogenic right ventricular dysplasia (ARVD) diagnosed at least 4 years later. VT catheter ablation was performed in 5 pts, only for a job in 1 pt. Three pts aged more 75 years died from non arrhythmic cause; one of them had a defibrillator. Other pts are alive without VT and without drugs in half of them. One pt developed dilated cardiomyopathy; 3 pts with initially LBBB pattern and left axis VT have signs of ARVD at MRI; 2 pts had permanent atrial fibrillation. All events occurred after 70 years or in pts with LBBB pattern and left axis VT. Secondary diagnosis of ARVD in pts with VT and apparent normal heart was not associated with a higher risk of events. The prognosis was only dependent on the age and the pattern of ECG in VT. It was favourable in pts younger than 70 years and those with typical ECG in VT, LBBB and inferior axis, RBBB and inferior or superior axis. A non medical treatment was rarely required.