[Use of digitalis glycosides in severe disorders of intra-ventricular conduction].

The use of digitalis in severe disorders of intra-ventricular conduction is debatable, and some consider it contra-indicated. Once it had been shown that the latter attitude is at best based on contraversial theoretical arguments, two types of study were undertaken: 1. Nine patients with bilateral bundle branch block had intracavitary recordings made of the HV interval both before and for one hour after the administration of lanatoside C (0.8 to 1.6 mg). In no case was this interval found to be increased, indicating that there was no increase in the original conduction defect. 2. Thirty four patients with complete right bundle branch block and associated left antero-superior hemiblock were digitalised, and followed up for an average of 16 months; only 2 complete atrio-ventricular blocks occurred (5.9%). The risk of complete atrio-ventribular block occurring within a year (4.5% in our series) does not differ significantly from that in an identical control group of 38 patients with the same conduction defect, but who were not digitalised (6%). Three patients had a therapeutic overdose of digitalis with no observed increase in their atrio-ventricular block. The authors conclude that it is perfectly in order to digitalise a patient with a severe intra-ventricular conduction defect.