Pindolol for ventricular arrhythmia

The role of pindolol in treating ventricular arrhythmia was studied in 43 patients with this disorder. Of these patients, 23 had coronary heart disease, 5 had valvular disease, and 15 had no demonstrable heart disease. patients underwent acute drug testing with 20 mg pindolol (phase 1) followed by maintenance therapy (phase 2) for 3 days (20 to 80 mg daily). Efficacy during both phases was evaluated by ambulatory monitoring and treadmill exercise testing. During acute drug testing, 50% of te patients responded. A concordant response between acute drug testing and phase 2 monitoring was seen in 81% (p less than 0.005) of patients and between acute drug testing and phase 2 exercise testing in 88% (p less than 0.005). Arrhythmia was suppressed during the phase 2 exercise test in 53% of patients; these included 80% of the patients without heart disease and 50% of those with coronary heart disease (not significant). During phase 2 monitoring, 60% of patients without heart disease responded vs. 25% with coronary heart disease (not significant). Side effects occurred in 12 patients (28%). These included congestive heart failure (3 patients); fatigue, lightheadedness, and insomnia (2 patients each); nausea, tremor, urinary retention, and bronchospasm (1 patient each); and aggravation of arrhythmia (7 patients). It is concluded that although pindolol alone is marginally effective for treating ventricular arrhythmia in patients with coronary heart disease, it appears to be more valuable in those without heart disease, especially when arrhythmia is provided by exercise. Acute drug testing proved highly predictive of the results with maintenance therapy and is a valuable rapid-screening procedure for identifying potential responders to pindolol.