Electrical and mechanical asynchronism in the cardiac cycle. A study of 100 ventricular premature beats by simultaneous right and left ventricular gatheterization

Electrical ventricular asynchronism may occur in man in bundle branch block, complete heart block with an idiovcntricular rhythm, ventricular premature beats and the Wolff-Parkinson-White syndrome. This paper is a study of the problem of whether mechanical ventricular asynchronism is a necessary consequence of electrical ventricular asynchronism such as occurs in the above situations. The data were obtained in intact man during the course of simultaneous right and left heart catheterization. The results indicate that mechanical ventricular asynchronism is infrequently seen in ventricular premature beats produced during the course of simultaneous combined heart cathetcrization. Mechanical asynchronism in onset of ventricular isometric contraction was absent in 72 of 100 ventricular premature beats with widened aberrant QRS complexes.