were usually recorded up to 25 mm from the plane of the tricuspid valve annulus and only rarely beyond this site, indicating that the electrical activity in the right bundle branch was isolated from right ventricular myocardium to a site 25 mm away from the tricuspid annulus in the patients studied. In one patient with right bundle branch block pattern on the electrocardiogram induced by a vent...

Multipoint 1 recording apparatus has been used to study the pattern of ventricular excitation in experimental bundle-branch block. After block, the wave of activation spreads uniformly from the contralateral ventricle across the septum to the free wall of the homolateral ventricle. Septal activation consumes more time than in the normal. Changes occur in the site and extent of early endocardia!...

was common (49%), and evidence is produced which suggests that it is probably the result of the ventriculotomy rather than direct trauma to the right bundle. Right bundle-branch block with left anterior hemiblock was less common (II%). Right bundle-branch block with left anterior hemiblock, especially if associated with a prolonged PR interval (trifascicular block), may predispose to complete a...

The electrocardiographic patterns encountered in 28 patients with pulmonary hypertension secondary to chronic lung disease have been studied. Thirteen had neither right ventricular hypertrophy nor right bundle-branch block; eight had either right ventricular hypertrophy alone or right ventricular hypertrophy and right bundle-branch block (complete or incomplete); and seven had incomplete right ...

Simultaneous tracings of right and left ventricular leads were taken in 6 dogs with experimentally produced left bundle-branch block, and in 30 clinical cases of left ventricular hypertrophy. In the experimental study it was found that the initial phase of the QRS complex in the right epicardial lead did not change its configuration or its duration after the production of left bundle-branch blo...

OBJECTIVE To compare the different effects of right ventricular pacing and classic left bundle branch block on left ventricular function. DESIGN Retrospective and prospective study of 48 patients by electrocardiography, and M mode, cross sectional, and Doppler echocardiography. SETTING A tertiary cardiac referral centre. PATIENTS 48 patients (age range 21 to 89 years, 15 women), 24 with a...

The effects of alternating cycle lengths (bigeminal rhythm) on His-Purkinje system refractoriness were studied in 14 patients using His bundle and right bundle recordings. Programmed atrial stimulation at constant cycle length (method I) was scanned using the atrial extrastimulus technique (A2) and compared with an atrial cycle length of identical duration coupled to A2 on alternate beats (meth...

Histopathological studies of the conduction system were related to His bundle electrogram recordings in seven patients with acute myocardial infarction and atrioventricular (A-V) conduction disturbances. The three patients with inferior infarctions had normal width QRS complexes and delay or block of the impulses above the His bundle. Recent ischemic changes were present in the A-V node in two ...

Ballstocad(liographic studies were done on 28 subjects with left bundle branch block and on 18 subjects with right bundle branch block. The influence of ventricular as nchronism, and the predominance of left or right ventricular disease, upon the derivation and interpretation of the ballistocar(liograsn, is discussed. The ballistocardiogram was found to be a valuable objective guide in the dete...