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.