left bundle branch block


Also found in: Dictionary, Acronyms, Wikipedia.

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.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

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.).
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Left bundle branch block (LBBB) is an abnormality of cardiac conduction system which causes delayed activation of left ventricle leading to delayed left ventricular contraction compared to the right ventricle.
Bramlage et al., "Clinical impact of a new left bundle branch block following TAVI implantation: 1-year results of the TAVIK cohort," Clinical Research in Cardiology, vol.
Ali M et al in their study conclude that the patients with left bundle branch block showing moderate to severe reversible perfusion defects on dipyridamole thallium cardiac SPECT have high likelihood of coronary artery disease16.
Based on results from randomized clinical trials, the international guidelines for treatment of patients with acute ST-elevation myocardial infarction (STEMI) recommend immediate reperfusion therapy, preferably primary percutaneous coronary intervention (PCI) in patients with chest pain and suspected new-onset left bundle branch block. (Kushner et al 2009)
13 hours after her injury, she developed a third-degree AV block along with left bundle branch block with the rate of 55bpm (see Figure 3).
"We gave the greatest strength of recommendation for patients with a wide QRS interval and left bundle branch block, a modest recommendation for patients with a less wide interval, and an equivocal recommendation for those without left bundle branch block.
Will this "left bundle branch block" kill me, or is there a cure?
Left bundle branch block (LBBB) and wide QRS complex are surrogates of left ventricular dyssynchrony that are commonly found in heart failure patients, and their presences associated with increased mortality [4-6].
The FDA will look at the panel's feedback as it considers 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%, left bundle branch block (LBBB), and a QRS duration greater than or equal to 120 milliseconds.
Abnormalities, noted in patients ECGs' were as follows: ST depression (Minnesota code 4.1.2: STJ depression [greater than or equal to] 1 mm but < 2 mm and ST segment horizontal or downward sloping in any of leads V1, V2, V3, V4, V5), T-wave changes (Minnesota code 5.2: T amplitude negative or diphasic with negative phase at least 1 mm but not as deep as 5 mm in lead I or V6, or in lead aVL when R amplitude is [greater than or equal to] 5 mm), early QRS transition zone (Minnesota code 9.4.1: QRS transition zone at V3 or to the right of V3 on the chest), complete right bundle branch block (RBBB) (Minnesota code 7.2.1), complete left bundle branch block (LBBB) (Minnesota code 7.1.1).