Paroxysmal ventricular tachycardia with rhythmic alternation in direction of the ventricular complexes in the electrocardiogram: Report of two cases and review of the literature

Abstract

1. 1. Two cases of alternating bidirectional paroxysmal ventricular tachycardia are reported, with a review of the literature. The new cases reported alternate in cycle length as well as in direction. 2. 2. Etiologically alternating bidirectional paroxysmal ventricular tachycardia seems to be associated with severe heart disease and congestive or anginal failure, and in some cases with excessive administration of digitalis. 3. 3. Clinically these cases are of especial interest because of their bad prognosis. 4. 4. We have considered several possible mechanisms for this unusual tachycardia and on the basis of careful measurement of the electrocardiographic plates have ventured to suggest the possibility of a double ventricular circus movement as a likely mechanism.