[Efficacy of the combination of low doses of beta-blockers and amiodarone in the treatment of refractory ventricular tachycardia].

Thirty one patients aged 56 +/- 16 years with chronic ventricular tachycardias (VT) refractory to 4.4 +/- 1.8 antiarrhythmic drugs, used alone or in combination, were managed by low doses of beta-blocker agents combined with oral amiodarone, either after loading (1.2 g for 7 days, n : 7) or reloading (1.2 g for 4 days, n : 24) of amiodarone. All patients proved refractory to amiodarone alone. Nine VT were also refractory to endocardial catheter fulguration in 8 patients. Twenty one patients had coronary artery disease, 4 had arrhythmogenic right ventricular dysplasia, 4 had dilated cardiomyopathy, 1 had valvular disease, and 1 had no structural heart disease. Twelve patients had an ejection fraction less than 30 p. 100. Ten patients were in NYHA functional class 3. VT was permanent in 3 patients, daily in 5, weekly in 7, paroxysmal in 16. In 14 patients, VT occurred both at day and night. Oral administration of a daily low dose of a beta-blocker agent (acebutolol 100 mg, betaxolol 5-10 mg, metoprolol 50-100 mg, nadolol 20-40 mg, pindolol 2.5 mg, propranolol 30 mg, sotalol 80-160 mg, tertatolol 2.5 mg) combined with 400 mg per day of amiodarone suppressed VT episodes in all patients. None presented heart failure or collapse. The mean reduction of the heart rate was about 17 p. 100. One patient need a definite pacemaker to correct sinus bradycardia. At discharge, exercise ECG (n: 20) induced non sustained VT in 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)