Correlation between the duration of the cardiac cycle and the complex of impedance plethysmographic hemodynamic indices of the lung and aorta.

Rheographic studies of the lung and aorta have been performed on 20 patients with atrial fibrillation and on 30 normal individuals before and after Valsalva's manoever. The findings disclose a strongly expressed positive correlation between the duration of the cardiac cycle and the rheographic systolic index, a Vmax., a Vm and a negative correlation with the Q-a interval and the ab/RR of the lung and the aorta.