Because there is a paucity of information on the perioperative risk of developing complete heart block among patients with bifascicular block (either right bundle branch block and left anterior hemiblock or left bundle branch block) and a long PR interval on the surface electrocardiogram, we undertook an analysis of 76 such patients. Twenty-three patients had right bundle branch block and left ...

Vectorcardiograms of paced and unpaced beats were recorded from 18 patients with implanted pacemakers to investigate the characteristics of post-pacing T inversions. The intraventricular conduction during sinus rhythm of unpaced beats was normal in 13 of 18 patients and abnormal in the other 5 (RBBB in 3, LBBB in 2). The directions of the maximum QRS vector in paced beats (max QRSp.V) and maxim...

Three cases in which left anterior hemiblock (LAH) obscured the diagnosis of right bundle branch block (RBBB) are reported. The RBBB was incomplete in one case and complete or of high degree in the other two. The LAH was intermittent in two cases. In the three cases, the LAH abolished not only the S waves in leads I and aVL, but also the terminal R wave in Vl. The possibility that RBBB, complet...

Right bundle branch block (RBBB) is occasionally encountered in young persons who lack any other evidence of overt cardiac disease (Hiss and Lamb, 1962; Lancaster, Schechter, and Massing, 1972). The block may be complete or incomplete, the latter being more common. Right bundle branch block has been studied in relation to body weight, obesity, serum cholesterol and glucose levels, and blood pre...

This study concerns two cases of chronic 2 degrees atrioventricular (A-V) block with left bundle branch block (LBBB). Pathological studies included serial section of the conduction systems. Case 1 had type I 2 degrees block with LBBB. Electrophysiological studies revealed type I 2 degrees block proximal to the His bundle recording site and a prolonged H-V interval (60 msec). Pathologically ther...

BACKGROUND Facet joint disease plays a major role in axial low-back pain. Few diagnostic tests and imaging methods for identifying this condition exist. Single photon emission computed tomography (SPECT) is reported that it has a high sensitivity and specificity in diagnosing facet disease. We prospectively evaluated the use of bone scintigraphy with SPECT for the identification of patients wit...

Multiple-block prediction is emerging as a new and exciting research area. Highly accurate multiple-block predictors are essential for wide instruction fetch mechanisms, that will support future generations of microprocessors. The block-based trace cache is a recent proposal for wide instruction fetch. It aligns and stores instructions at the basic block level instead of at the trace level, thu...

The mechanism of origin of ventricular premature depolarizations (VPDs) is explained by automaticity or reentry. We studied three patients with intermittent left bundle branch block (LBBB) and unifocal VPDs of right bundle branch block (RBBB) morphology (assumed left ventricular origin). We examined the effect of different types of intraventricular conduction on the coupling intervals of the VP...

Premature ventricular contraction (PVC) is one of the most serious arrhythmias. Without early diagnosis and proper treatment, PVC can result in significant complications. In this paper, a novel feature extraction method based on a sparse auto-encoder (SAE) and softmax regression (SR) classifier was used to differentiate PVCs from other common Non-PVC rhythms, including normal sinus (N), left bu...

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 ...