ELECTROKYMOGRAPHY OF THE HEART AND GREAT VESSELS: PRINCIPLES AND APPLICATION

Abstract

The electrokymograph (eky) is an instrument which permits the graphic registration of the movements of the heart and great vessels. It was designed as an attachment for use with the roentgenoscope and the ecg. When these 3 units are utilized together for the purposes of eky., the roentgenoscope provides means for observing the cardiac silhouette and positioning the eky. unit over a selected area; the eky. converts the motions and density changes of selected areas to current variations, which the ecg. records on bromide paper. Repeated eky''s. from 140 normal subjects gave characteristic ventricular atrial, and arterial curves susceptible of physiological interpretation on the basis of the phases of the cardiac cycle. Eky''s. on patients with premature contractions, auricular fibrillation, atrioventricular dissociation, myocardial infarction, bundle-branch block, and aortic regurgitation were found to be consistent with those conditions. The density type curve is discussed with respect to its possible application to cardiac output measurements.