►Implication for health policy/practice/research/medical education: This report demonstrates new criteria for patient selection in CRT era. We started diagnosing Bundle Branch Block about 100 years ago on dog models (1). However, about 40 years passed until we could diagnose Left Bundle Branch Block (LBBB) correctly on ECG (2). Today, we have conventional criteria for diagnosing LBBB, including...

AIMS Left bundle branch block (LBBB) often causes septal perfusion defects in radionuclide myocardial perfusion imaging using exercise (Ex) but rarely using vasodilator stress. We studied whether this is due to an underlying structural disease inherent to spontaneous LBBB or whether it is also found in temporary LBBB induced by right ventricular pacing (PM) indicating a functional rather than a...

Patients with a suspected acute coronary syndrome and left bundle branch block (LBBB) present a unique diagnostic and therapeutic challenge to the clinician. Although current guidelines recommend that patients with new or presumed new LBBB undergo early reperfusion therapy, data suggest that only a minority of patients with LBBB are ultimately diagnosed with acute myocardial infarction, regardl...

The effects of left bundle branch block (LBBB) on left ventricular myocardial metabolism have not been well investigated. This study evaluated these effects in patients with coronary artery disease (CAD).Sixty-five CAD patients with complete LBBB (mean age, 61.8 ± 9.7 years) and 65 without LBBB (mean age, 59.9 ± 8.4 years) underwent single photon emission computed tomography, positron emission ...

SUMMARY The direction of the initial 20 to 30 msec forces of multiple unipolar and transseptal bipolar intraventricular electrocardiograms was examined in five patients with and five without incomplete left bundle-branch block (LBBB) and in one patient with complete LBBB. The data obtained were consistent with preservation of the normal left-to-right and apex-to-base direction of septal depolar...

Positive responses to left (LV) and biventricular (BV) stimulation observed in heart failure patients with left bundle branch block (LBBB) suggest a possible mechanism of LV resynchronization. An anesthetized canine LBBB model was developed using radio frequency ablation. Before and after ablation, LV pressure derivative over time (dP/dt) and aortic pulse pressure (PP) were assessed during norm...

OBJECTIVES Recently published clinical guidelines recommend cardiac resynchronisation therapy (CRT) for patients with heart failure (HF) with reduced LVEF and non-left bundle branch block (non-LBBB) QRS morphology. We sought to define the potential benefit of CRT in these patients through meta-analysis of randomised controlled trials (RCTs) that have reported outcomes in patients with non-LBBB ...

BACKGROUND In patients with idiopathic dilated cardiomyopathy (IDCM) a prolongation of left ventricular (LV) systole at the expense of diastolic time was demonstrated. Our study was aimed to evaluate the effect of exercise on heart rate corrected diastolic time in controls, IDCM with and without LBBB, and patients with LBBB and normal LV function. METHODS 47 patients with IDCM, 30 without LBB...

Letter by Jackson et al Regarding, “PR Interval Identifies Clinical Response in Patients With Non-Left Bundle Branch Block: A Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy Substudy” by Kutyifa et al Kutyifa et al present an interesting post hoc analysis of the Multicenter Automatic Defibrillator Implantation Trial-cardiac resynchronization therapy data...

BACKGROUND We evaluated the risk of incident heart failure (HF) associated with bundle-branch blocks (BBBs) in postmenopausal women. METHODS AND RESULTS Cox's regression was used to evaluate hazard ratios with 95% confidence intervals for HF among 65975 participants of the Women's Health Initiative (WHI) study during an average follow-up of 14 years. BBBs observed in 1676 women at baseline we...