EFFECT OF PHYSICAL EXERCISE AND ISOPROTEN OL IN PATIENTS WITH CHROMICATRIAL TACHYCARDIA

Tolerance to exercise and effect of exercise ana isoproterenol infusio n on cardiac rhythm were studied in 58 patients with chronic atrial ta chycardia (in 49 with constantly recurrent and in 9 with permanent tac hycardia). Veloergometry was used in all patients and isoproterenol in fusion test - in 26 patients. During exercise 34% of patients were in sinus rhythm and 66% had atrial tachycardia. The former group of patie nts had higher exercise tolerance while In the latter ability to perfo rm exercise was offen limited by high initial heart rate and by excess ive acceleration of the ectopic focus discharge in response to physica l effort. Exercise tests end tests with isoproterenol infusion yielded similar results in 17 of 26 patients. Both test had poor sensitivity for diagnosis of chronic atrial tachycardia but results of exercise te st could be used in selection of proper tactics of management of patie nts with this arrhythmia.