right bundle branch block
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right bundle branch block (RBBB)
impaired transmission or absence of transmission of electric impulses from the atrioventricular (AV) bundle of His to the right ventricle. The block may be complete or incomplete and may be caused by a lesion in the right bundle branch or a small, focal lesion in the AV bundle. RBBB is often associated with right ventricular hypertrophy, especially in athletes and individuals under 40 years of age. In older individuals RBBB is commonly caused by coronary artery disease. A complete RBBB commonly occurs after surgical closure of a ventricular septal defect.
right bundle branch blockCardiology A condition in which the electrical impulse from the bundle of His to the ventricles is delayed or fails to conduct along the right bundle branch, resulting in right ventricular depolarization by cell-to-cell conduction spreading from the interventricular septum and left ventricle to the right ventricle–ie, slow and uncoordinated Natural history Surgically induced RBBB has few acute hemodynamic consequences and a generally benign course long term; rarely, progression to complete heart block and sudden death occur, especially if accompanied by major His-Purkinje system–eg, left anterior hemiblock, first-degree AV block–injury; tetralogy of Fallot repair with an RBBB and a markedly prolonged QRS duration >180 ms have an ↑ risk for ventricular arrhythmias and sudden death; familial RBBB may be benign or, if it occurs in Kearns-Sayre syndrome or Brugada syndrome, potentially fatal Clinical Children with RBBB may have Hx of congenital heart disease, heart surgery–eg, VSD, palpitations, ↓ energy/activity/exercise tolerance, dizziness, syncope, familial Hx of arrhythmias–eg, BBB, complete heart block, pacemaker/defibrillator, premature or sudden unexplained death, acute MI under age 45; persistently split 2nd HS EKG Lead V1–late intrisicoid deflection, M-shaped QRS, wide R or occasionally qR; lead V6–early intinsicoid deflection, wide S; lead I–wide S Management Pacemaker, if syncope or significant arrhythmias Followup Telemetry prn; annual EKG. See Bundle branch block. Cf Left bundle branch block.
right bundle branch blockAbbreviation: 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.
See also: bundle branch block