The diagnosis or ventricular tachycardia with ventriculo-atrial conduction.

A 57 year old man developed recurrent tachycardia with QRS complexes of 0.13 second in duration at a rate of 140 beats per minute. Inverted P waves appeared to follow each QRS complex in the electrocardiographic leads II, III and aVF. The differentiation between ventricular tachycardia with1 : 1 V-A conduction and supraventricular tachycardia with aberrant ventricular conduction was difficult to make from the surface electrocardiogram. This differentiation is important for selection of appropriate therapy. The diagnosis of ventricular tachycardia with 1 : 1 V-A conduction was clearly established in this case on simultaneous recording of surface electrocardiogram, His bundle electrogram and high right atrial electrogram.