A Study on the Spread of Excitation in Human Right Ventricular Septum Using Newly Designed Multi-bipolar Electrode Catheter

Abstract

Since about 20 years ago, conduction pattern of the intraventricular activation has been studied and clarified electrophysiologically in animals. However the knowledge in human beings is still lacking, maybe due to technical difficulties: single bipolar electrode catheter has been used for that purpose. Therefore the author attempt-ed to analyse the right ventricular conduction pattern in detail and accurately with newly designed electrode catheter in normal QRS, atrial septal defect (ASD) with incomplete right bundle branch block and complete right bundle branch block (C-RBBB) of human beings. Materials and Methods: Thirty-eight subjects were studied. They were 24 cases with normal QRS, 4 cases with ASD (type of secundum) in which L-R shunt rate was 29 to 87.5 percent and 10 cases with C-RBBB. The author designed a new electrode cathter to which 5 pairs of electrode were atached, in order to record His bundle electrogram and intraventricular activation potentials simultaneously. The interelectrode distance between each electrode of each pairs is 1 mm and the distance between midpoints of two adjacent pairs is 13 mm. The catheter was inserted into the right femoral vein or right major saphenous vein and under fluoloscopy introduced into right ventricle, thereafter it was positioned at the site where proximal His potential was recorded most obviously with the most proximal pairs of electrode I -2. Right ventricular subendocardial activation waves (V1 to V5, respectively) were recorded with each pairs of electrode 3-4, 5-6, 7-8, 9-10 in turn from proximal to distal portion . Each V waves were recorded simultaneously at I 5 inches/sec on data recorder through amplifier with time constant of 0.003 sec and high filter setting of 300 Hz. After the study the tape was reviewed at 7.5 inches/sec through band pass filter settings of 120-500 Hz. The data was then photographed on paper at 200 mm/sec in electro-visigraph. Results: (1) Distribution of right ventricular subendocardial activation in normal QRS: The interval from proximal His to the earliest activation point of V4 was 52.5 ± 7.4 msec which was the shortest, then the activation point was progressively prolonged to V5, V3, V2 and