Effects of disopyramide on electrophysiological properties of specialized conduction system in man and on accessory atrioventricular pathway in Wolff-Parkinson-White syndrome.

These findings suggest that disopyramide would be a useful and safe drug in the management of certain atrial and ventricular arrhythmias and in the management of the Wolff-Parkinson-White syndrome with atrial fibrillation

R A Spurrell; C W Thorburn; J Camm; E Sowton; D C Deuchar

2007

Scholarcy highlights

  • Seven patients with normal specialized conduction system and three patients with the Wolff-Parkinson-White syndrome were studied using programmed stimulation of the feart before and after the administration of intravenous disopyramide
  • Using techniques of intracardiac recordings and programmed electrical stimulation of the heart, we have studied the effects of disopyramide on the electrophysiological properties of the specialized conduction system in man, and in addition its effect on the anomalous atrioventricular pathway in the Wolff-Parkinson-White syndrome
  • In 4 patients the HRA-LRA interval increased by io ms suggesting an increase in atrial conduction time
  • Cases 8 and I0 the effective refractory period of the anomalous pathway for antegrade conduction increased by 50 ms and 65 ms, respectively, and for retrograde conduction by 40 ms in both patients
  • In this study disopyramide has been shown to delay conduction and prolong the effective refractory period of the anomalous bypass in the WPW syndrome and so should be of value in the termination of the circus movement tachycardia, and the tachycardia was terminated in Cases 9 and io
  • The tachycardia was not terminated by the drug in Case 8 and this may be because disopyramide had prolonged the conduction times in both parts of the re-entry circuit, thereby allowing a balance of conduction time and refractoriness to remain between antegrade conduction in the atrioventricular node His pathway and retrograde conduction in the anomalous pathway such that the tachycardia could continue but with a longer cycle length
  • In this paper disopyramide has been shown to prolong the effective refractory period of the anomalous bypass and so should be a safe and useful drug to administer to patients with the WPW syndrome and atrial fibrillation

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