Analysis of cerebral echo-pulsation curves and plethysmograms in cases of cardiac arrhythmia

Cerebral echo-pulsations in 18 patients with atrial fibrillation of the heart were compared with finger and toe plethysmograms. A normalization technique was used to equalize curves recorded with different kinds of measurements. The average linear correlation coefficient between echo-pulsation and plethysmographic curves was 0.72 and indicates that a relationship exists between the RR-interval of the E.C.G. and the amplitude of echo movements in range and plethysmographic excursions.