Abstract

OBJECTIVE--To examine the effect of exercise on cycle length in atrial flutter. PATIENTS--15 patients with chronic atrial flutter. Seven patients were taking digoxin and six verapamil; two were not taking medication. METHODS--All patients underwent bicycle ergometry. Flutter cycle length was measured at rest and at peak exercise. RESULTS--Mean flutter cycle length increased from 245 ms to 256 ms (P = 0.002). Six patients developed 1:1 atrioventricular conduction. Significant increases in flutter cycle length were observed irrespective of development of 1:1 atrioventricular conduction and use of digoxin and verapamil. CONCLUSION--Exercise prolongs flutter cycle length. This effect would promote development of 1:1 atrioventricular conduction during exercise, causing inordinately high ventricular rates.