Haemodynamic effects of intravenous disopyramide in heart failure

The haemodynamic effects of disopyramide have been studied in 11 patients with manifest or imminent heart failure. Disopyramide, 2 mg per kg body weight, was given intravenously during right and left heart catheterisation. The cardiac index decreased by an average of 28% (p less than 0.01); mean maximal left and right ventricular end-diastolic pressures were increased by 5.0+/-0.9 mm Hg (p less than 0.01) and 5.0+/-0.6 mm Hg (p less than 0.05), respectively; and left ventricular systolic pressure fell slightly but significantly (p less than 0.05). No significant change in right ventricular systolic pressure was seen. Pulmonary wedge pressure rose on average by 2.7 mm Hg (p less than 0.05). No significant change in heart rate was observed in 5 patients with sinus rhythm. In 6 patients with atrial fibrillation, there was a significant (p less than 0.01) increase in heart rate; the average increase in heart rate for the entire group was 19.6 beats per minute. The maximum effect on all the parameters occurred 7-11 minutes after the injection, and it gradually subsided during the following 10 minutes. It was concluded that disopyramide had a potentially serious myocardial depressant effect.