Tilt testing is a commonly used diagnostic tool to evaluate syncope of undetermined etiology. We hereby describe a twelve year old male child who developed presyncope during provocative head up tilt testing along with ST segment elevation in cardiac monitor during presyncope. Patient underwent repeat head up tilt testing along with holter monitoring which showed a left bundle branch block escap...

Cardiac resynchronization therapy (CRT) typically is attempted with biventricular pacing (BiVP). One-third of patients are nonresponders. Left-bundle (LBP) an alternative means effective CRT because it can correct the left bundle branch block. We assessed feasibility and clinical response LBP as to BiVP in CRT-indicated patients.

Electrophysiological and histological correlation was documented in 2 cases of complete heart block (CHB). Case 1 (77 yrs. female): CHB continued for 1.5 years with normal QRS in axis and duration. The His bundle electrogram (HBE) showed A-H block with normal H-V interval (40 msec). Ten months later she died of bronchopneumonia and paralytic ileus. Histological study of the conduction system re...

A method of vectorcardiography, in which the projections of the spatial veetorcardiogrami in various planes of an equilateral tetrahedron reference system are recorded, has been applied to the study of left bundle branch block. Results suggest that the method employed may provide information relative to the state of the miyocar(liutim and the extent of myocardial lesions which is not evident fr...

Electrode catheter recordings of the bundle of His (H), the right bundle branch (RB) and the left bundle branch (LB) were obtained in 15 dogs without thoracotomy during sinus rhythm and digitalis-induced ventricular tachycardia. During sinus rhythm an H-RB-LB sequence was recorded. This sequence was unchanged during atrial stimulation at rapid rates or during cardiac slowing by vagal stimulatio...

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...

The tracings of two patients with acute myocardial infarction showing complete right bundle branch block and alternating block in the divisions of the left branch are presented. Both developed a type II (Mobitz) block which was attributed to a simultaneous interruption of conduction in the three main intraventricular tracts (trifascicular block). Left divisional blocks produced specific changes...

A clinical-pathologic study was made of 50 patients with complete left bundle branch block who had postmortem examinations performed at three Salt Lake City hospitals. Forty (80 percent) were found to have left ventricular hypertrophy as determined from measured left ventricular wall thickow but only 14 had electrocardiographic evidence of this while two of the ten patients without left ventric...

Synchronized left ventricular pacing (sLVP) via adaptive cardiac resynchronization therapy (aCRT) algorithm might enhance the efficacy of CRT. A 71-year-old female was admitted with the diagnosis of heart failure. Electrocardiograms revealed left bundle branch block with QRS width of 144 ms, and frequent premature ventricular complexes (PVCs). A CRT device was implanted, and sLVP via a CRT algo...

A patient with tricuspid atresia and characteristic electrocardiographic features of counterclockwise and superiorly oriented frontal plane QRS loop (left anterior hemiblock) is presented. Operative intervention resulted in a clockwise and inferior rotation of the frontal QRS loop (left posterior hemiblock) without the development of complete left bundle branch block. This observation suggests ...