Mechanically Induced Ventricular Systoles During External Cardiac Massage and Thumping of the Chest

Abstract

The correlation between cardiac compression, ECG potentials and the rise of intracardiac and arterial pressure was studied in dogs during external cardiac massage and thumping of the chest. The direct mechanical effect of the compressions was unsatisfactory. The compressions often elicited QRS complexes, particularly with thumping of the chest, which were frequently followed by a secondary rise of pressure equal to that associated with spontaneous heart beats. The time analysis indicated that the artificially elicited QRS complexes had evoked effective heart contractions. This indirect mechanical effect of compressions of the chest was much superior to the direct effect and is probably of major importance for resuscitation.