left bundle branch block


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left bundle branch block (LBBB)

the failure of the cardiac impulse to propagate down the left bundle branch from the bundle of His, resulting in early activation of the right side of the septum and the right ventricular myocardium. See also bundle branch block.

left bundle branch block

Cardiology A condition in which ventricular contraction is not completely synchronized due to a block in conduction of an electrical impulse to the ventricles; in LBBB, right ventricular endocardial activation begins before, and is often completed before, initiation of left ventricular endocardial activation; benign LBBB is rare; preexisting LBBB in absence of clinical evidence of heart disease is rare; newly acquired LBBB has a 10-fold ↑ in mortality Clinical Generally asymptomatic, or absent or diminished 1st heart sound–HS and reversed splitting of 2nd HS EKG Lead V1–QS or rS; lead V6–late intrinsicoid deflection, monophasic R; lead I–monophasic R Management Pacemaker, if syncope or significant arrhythmias Followup Telemetry PRN. See Bundle branch block. Cf Right bundle branch block.

left bundle branch block

Abbreviation: LBBB
A defect in the conduction system of the heart in which electrical conduction down the left bundle branch is delayed. On the 12-lead EKG, it gives the QRS complex a widened QS complex in lead V1 (0.12 sec.).
References in periodicals archive ?
Thirty Six patients with complete left bundle branch block and have coronary angiography done within past 4 months were included in our study.
Kumar V, Venkataraman R, Aljaroudi W, Osorio J, Heo J, Iskandrian AE, Hage FG (2013) Implications of left bundle branch block in patient treatment.
This approval allows heart failure patients with left bundle branch block to benefit from this therapy," said Jeffrey Shuren, MD, director of the FDA's Center for Devices and Radiological Health.
Intermediate pretest probability patients with left bundle branch block require myocardial perfusion imaging
There was no evidence for left bundle branch block, and the rapid and complete resolution of ECG changes make pericarditis unlikely.
An ECG can also be difficult to interpret in cardiac conditions, such as left bundle branch block, ventricular paced rhythm, and left ventriculary hypertrophy.
The guidelines, last revised in 1998, also expand the use of ICDs to patients whose hearts pump with too little force and are hindered by a sluggish electrical system--a common conduction disturbance called left bundle branch block, which accounts for about 25 percent of patients with heart failure.
The ECG showed a sinus rhythm with left bundle branch block.
An ECG was scored abnormal if there was an abnormal rhythm (but not isolated ventricular extrasystoles), atrioventricular block, left bundle branch block, abnormal QT interval, significant left axis deviation, pathological Q waves, abnormal ST segment or T waves.
The panel voted in favor of the overall risk-benefit profile (Yes: 3 votes and No: 2 votes) The FDA will consider the Panel's feedback as it reviews Medtronic's request to expand its CRT-D indication to include New York Heart Association (NYHA) Class II heart failure patients with a left ventricular ejection fraction (LVEF) of less than or equal to 30 percent, left bundle branch block (LBBB), and a QRS duration greater than or equal to 120 milliseconds.
Procedural success was based on three criteria: 1) class improvement in NYHA class, 2) [greater than or equal to] 5 % improvement in ejection fraction (EF) and 3) conversion of Left bundle branch block (LBBB) into normal QRS complexes.
045), and those with the presence of left bundle branch block (LBBB) ( P = 0.