LBBB


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Related to LBBB: Left bundle branch block

LBBB

left bundle branch block; see bundle branch block, under block.

LBBB

abbreviation for left bundle branch block.

LBBB

Left bundle-branch block

bundle branch block

,

BBB

A defect in the electrical conduction system of the heart in which there is failure of conduction down one of the main branches of the bundle of His. On the surface electrocardiogram, the QRS complex is > 0.12 sec. and its shape is altered. Synonym: bundle branch heart block; interventricularheart 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.).

right bundle branch block

Abbreviation: RBBB
A defect in the conductive system of the heart in which electrical conduction down the right bundle branch is delayed. On the 12-lead EKG, it gives the widened QRS complex an RSR appearance in leads V1 and V2.

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 ?
If only a minority of patients with LBBB ultimately are diagnosed with AMI, false-positive cardiac catheterization laboratory activation is frequent.
Even tne substantial gap between recent evidence and current recommendations, new diagnostic strategies are needed to guide the selection of appropriate patients with suspected AMI and LBBB for urgent reperfusion therapy.
However, as a substantial proportion of LBBB patients do not have a STEMI-equivalent AMI but have an overall higher risk of bleeding (more likely female, older, and with pre-existing cardiovascular disease, hypertension, and congestive heart failure), transfer for primary PCI may be the preferred strategy, with judicious use of on-site fibrinolysis reserved for the patients who are highly likely to have a STEMI-equivalent AMI when PCI is not available.
Although few data are available, it is becoming increasingly more feasible to accelerate the timing of serial biomarker assessment, so that measurements are performed every 15 minutes, rather than every 60 to 90 minutes, in patients with LBBB and suspected AMI.
Bedside echocardiography may also be used as an adjunctive measure in clinically complex situations to gain additional insight as to whether a new or presumably new LBBB is the result of a STEMI-equivalent ACS presentation.
An algorithm was proposed for the diagnosis and management of LBBB patients with suspected myocardial infarction that includes a rapid clinical and ECG assessment (Neeland et al 2012).
Given the significant advancements in the efficacy and safety of AMI treatments and the lack of contemporary evidence for the existing approach to LBBB, more research encompassing additional diagnostic and therapeutic strategies is needed.
LBBB may induce abnormalities in the left ventricular performance due to abnormal asynchronous contraction patterns.
LBBB results in an altered pattern of LV activation and subsequent contraction.
QRS prolongation in LBBB has for long been known to cause abnormal ventricular contraction patterns with the depressed ejection fraction, and to be inversely related to the hemodynamic performance.