Clinical studyThe artificially paced human heart: I. Ballistocardiographic correlations with the changing P-R intervals☆

In 10 patients with complete heart block and an artificial ventricular pacemaker, there was a significant improvement in the form and amplitude of the ballistocardiographic complex when the P-R interval was 0.10 to 0.20 sec. Maximal ballistocardiographic improvement was associated with maximal increase in the brachial arterial systolic and pulse pressures. These findings suggest an improved efficiency of ventricular contraction in complete heart block when there is a normal sequence of atrioventricular activity. The hemodynamic consequences of the changing atrial systole-ventricular systole interval in complete heart block and their effect upon the ballistocardiogram are discussed.