Haemodynamic effect of intravenous verapamil in controlled atrial fibrillation.

The haemodynamic effect of intravenous verapamil was assessed in eight digitalised patients with atrial fibrillation, at rest and on exercise. The reported regularisation of the ventricular rate in atrial fibrillation with verapamil, was also examined. The only significant haemodynamic effect attributable to the drug was an increased stroke volume which was in accordance with significant heart rate slowing which occurred at rest and both during and after exercise. There was no significant change in cardiac output. Although the heart rate slowed in all studies, regularisation of the R-R interval did not occur.