Right ventricular (RV) pacing produces an iatrogenic form of left bundle branch block (LBBB). Intrinsic LBBB (I-LBBB) can cause adverse hemodynamic effects due to dyssynchrony, mainly in patients with heart failure and reduced ejection fraction (HFrEF). Although RV is thought create a similar activation pattern as LBBB, some studies suggest apical be harmful even I-LBBB. Currently, the mechanis...

A chronic hypertensive patient with electrocardiogram (ECG) showing left bundle branch block (LBBB) was given general anesthesia for right modified radical mastectomy. Her ECG reverted to normal sinus rhythm intermittently during peri-operative period. This intermittent ratedependent LBBB is a rare entity. Though hypertension is one significant co-morbid condition, the risk evalution of LBBB du...

BACKGROUND Left bundle branch block (LBBB) influences on regional left ventricular (LV) structure, perfusion, and metabolism have not yet been thoroughly investigated in dilated cardiomyopathy patients. METHODS AND RESULTS Eleven dilated cardiomyopathy patients with LBBB (mean+/-SD age, 62+/-11 years; LV ejection fraction, 35+/-8%) and 7 dilated cardiomyopathy patients without LBBB (mean+/-SD...

Background – Left bundle branch block (LBBB) influences upon regional left ventricular (LV) structure, perfusion and metabolism were not thoroughly investigated in dilated cardiomyopathy (DCM) patients. Methods and Results – Eleven DCM patients with LBBB (69±11 years, LV ejection fraction[EF]: 35±8%) and 7 DMC patients without LBBB (58±9 years, LV EF: 37±10%) were studied by cardiac magnetic re...

BACKGROUND Simple conceptual ideas about cardiac resynchronization therapy assume that biventricular (BiV) pacing results in collision of right and left ventricular (LV) pacing-derived wavefronts. However, this concept is contradicted by the minor reduction in QRS duration usually observed. We investigated the electric mechanisms of cardiac resynchronization therapy by performing detailed elect...

BACKGROUND A left bundle-branch block (LBBB)-like pattern with a dominant S-wave in V(1) is common in idiopathic ventricular arrhythmias (VA). Discrimination between idiopathic and scar-related LBBB pattern VA has important clinical implications. We hypothesized that the VA QRS morphology is influenced by the presence of ventricular scar, allowing ECG discrimination of VA arising from structura...

Left bundle branch block (LBBB) usually occurs as a postoperative complication from surgical correction of congenital heart disease and can be associated with hypertensive heart disease, coronary artery disease, myocarditis, and aortic valvular disease. Although isolated LBBB is a conduction abnormality found in some healthy adults, it has not been reported in pediatric population. We report a ...

A 53-year-old man with depressed ejection fraction (EF) of 35% and QRS width of 88 ms at rest was admitted to our institution with a complaint of exertional chest discomfort and dyspnea. During treadmill exercise, left bundle-branch block (LBBB) with a QRS width of 152 ms occurred at a heart rate of 100 bpm. During LBBB, the patient showed significant mechanical dyssynchrony as evidenced by a t...

SUMMARY A clinical, electrocardiographic, phonocardiographic, and arteriographic study was made of 20 normal subjects, 20 patients with right bundle-branch block (RBBB) and 20 patients with left bundle-branch block (LBBB). Ventricular asynchronism was documented in nearly all cases of bundle-branch block by the behavior of the arterial pulse and the heart sounds. The first heart sound was of no...

OBJECTIVES This study evaluated the predictive factors and prognostic value of new-onset persistent left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve implantation (TAVI) with a balloon-expandable valve. BACKGROUND The predictors of persistent (vs. transient or absent) LBBB after TAVI with a balloon-expandable valve and its clinical consequences are unknown. M...