The effect of intravenous disopyramide phosphate on recurrent paroxysmal tachycardias.

Abstract

1 Recurrent paroxysmal atrial, atrioventricular and ventricular tachycardias in 50 patients without acute coronary insufficiency, heart failure or metabolic abnormality were treated with disopyramide phosphate in a dose of 2 mg/kg body weight infused over 5 min. 2 Conversion to sinus rhythm within 10 min of the completed infusion occurred in 10 of 14 (7 1%) patients with paroxysmal 'lone' atrial fibrillation, 3 of 7 (43%) patients with paroxysmal atrial flutter, 6 of 9 (67%) patients with paroxysmal atrial tachycardia, 5 of 9 (56%) patients with paroxysmal atrioventricular tachycardia associated with the Wolff-Parkinson-White syndrome and 8 of 11 (73%) patients with paroxysmal ventricular tachycardia. 3 Side effects: significant systemic hypotension in 3, high grade AV block in 1, an increased ventricular response producing symptoms in 4, post conversion asystole in 1 and sinus bradycardia in 2. 4 The anti-arrhythmic effect and arrhythmogenic side effects may be related to both the direct membrane stabilizing effect and the anticholinergic effect of disopyramide.

Effect of Bepridil in Atrial Fibrillation Inducibility Facilitated by Vagal Nerve Stimulation - Prevention of Vagal Nerve Activation-Induced Shortening of the Atrial Action Potential Duration -

“…26 A similar observation was made in this study, although the electrophysiological mechanism appeared different from that associated with anticholinergic drugs. In our previous study, using the same model of AF, the VNS-induced prolongation of sinus cycle length and increase in HF-amp were counteracted by disopyramide, which effectively blocked the activation of muscarinic M2 receptors in the atrium.…”