Cardiovascular Complications of Outpatient Cardiac Rehabilitation Programs’ Journal of the American Medical Association, September 5, 1986, Vol. 256, No. 9. Virginia Heart Institute data participation.

Sixty-four patients with reproducible exercise-induced ventricular arrhythmias were enrolled in an open-label, multicenter study to assess the efficacy and safety ot oral nadolol therapy. There were 53 men and 11 women ranging in age from 19 to 75 years (mean 53.9). The severity of arrhythmias varied from frequent ventricular premature beats to nonsustained and sustalned ventricular tachycardias. Using serial treadmill exercise tests, patients underwent dose titration for 1 month and were followed up for 3 tO 6 months. Depending on drug tolerance and response to treadmill exercise testing, the single daily required dose of oral nadolol ranged from 20 to 240 mg (average 66). Twenty-three (36 %) of the patients experienced a total of 30 adverse effects of nadolol therapy; however, only 9 (14%) patients had to be withdrawn from the study. The adverse effects observed were those commonly associated wlth ,B-adrenergic blocking agents, and all were dose-dependent and reversible.

At the last patient visit, the severity ot exercise-induced ventricular arrhythmias was signiticantly decreased compared wlth pretreatment in 36 (75%) of 48 evaluable patients. Elghteen (38%) ot the patients demonstrated total suppresslon of arrhythrnlas. This was accompanied by signincant increases from pretreatment in both the mean duration of symptom-limited exercise (+1.02 ±0.41 minutes, p <0.05) and the mean time of exercise required for arrhythmia inductlon (+1,80 ±0.66 minutes, p <0.01), a signficant decrease from pretreatment in the mean peak exercise double-product ( – 4,775, p <0.001) and a decrease in the incidence ot exercise-induced ST-segment depresslon ( – 33%). Oral nadoial in once-daily doses is beneficial and efficacious in suppressing exercise induced ventricular arrhythmias and adverse effects of oral nadoiol therapy are not uncommon but are cilinically manageable.