Diaphragmatic juxtacardiac leads: Their value in the study of the spread of activation and the QRS complex of the heart's diaphragmatic surface

Abstract

In 12 patients who underwent gastric surgery, juxtacardiac diaphragmatic leads were recorded. In normal patients the recorded morphologies were: qRs, qRS, qR, and Rs in the left lateral portion of the cardiac impression of the diaphragm, and rS or double R and S in the right lateral portion. Thus, complexes without Q waves are recorded in zones corresponding to the left ventricle. This is not observed in the anterior and lateral surfaces of this ventricle. It is suggested that the diaphragmatic surface of the right ventricle, through its basal portions near the right border, interferes directly in the genesis of the delayed R waves of the RSR′ and RSR′S complexes. By the study of the S 1-S 2-S 3 pattern it was concluded that even in normal people this pattern is due to a special and uncommon type of ventricular activation. The data obtained in this study was related to data obtained previously with the direct epicardial leads, in an attempt to complete our knowledge of the sequence of cardiac activation. In both normal and pathologic cases the P wave is always positive. The T wave, except in few points near the right border of the heart, is always positive.