Right bundle branch block - wikipedia Right bundle branch block Right bundle branch block ECG characteristics of a typical RBBB showing wide QRS complexes with a terminal R wave in lead V1 and slurred S wave in lead V6. Classification and external resources Specialty Cardiology ICD - 10 I45. 1 ICD - 9 - CM 426.4 DiseasesDB 11620 eMedicine ped / 2500 ( edit on Wikidata ) A right bundle branch block ( RBBB ) is a heart block in the electrical conduction system. During a right bundle branch block, the right ventricle is not directly activated by impulses travelling through the right bundle branch. The left ventricle however, is still normally activated by the left bundle branch. These impulses are then able to travel through the myocardium of the left ventricle to the right ventricle and depolarize the right ventricle this way. As conduction through the myocardium is slower than conduction through the Bundle of His - Purkinje fibres, the QRS complex is seen to be widened. The QRS complex often shows an extra deflection which reflects the rapid depolarisation of the left ventricle followed by the slower depolarisation of the right ventricle. In most cases right bundle branch block has a pathological cause though it is also seen in healthy individuals in about 1.5 - 3 %. Contents 1 Diagnosis 2 Causes 3 Epidemiology 4 Treatment 5 See also 6 References Diagnosis Normal electrical conduction system of the heart ( Schematic ). All myocardial segments are excited almost simultaneously ( purple staining ). Sinoatrial node Atrioventricular node Conduction in RBBB ( Schematic ) : With a blockage in the right bundle branch ( red ), the left ventricle is excited in time ( purple ), while the excitation of the right ventricle takes a detour via the left bundle branch ( blue arrows ). The criteria to diagnose a right bundle branch block on the electrocardiogram : The heart rhythm must originate above the ventricles ( i.e. sinoatrial node, atria or atrioventricular node ) to activate the conduction system at the correct point. The QRS duration must be more than 100 ms ( incomplete block ) or more than 120 ms ( complete block ) There should be a terminal R wave in lead V1 ( e.g. R, rR ', rsR ', rSR ' or qR ) There should be a slurred S wave in leads I and V6. The T wave should be deflected opposite the terminal deflection of the QRS complex. This is known as appropriate T wave discordance with bundle branch block. A concordant T wave may suggest ischemia or myocardial infarction. A mnemonic to distinguish between ECG signatures of left bundle branch block ( LBBB ) and right, is WiLLiaM MaRRoW ; i.e., with LBBB, there is a W in lead V1 and an M in lead V6, whereas, with RBBB, there is an M in V1 and a W in V6. RBBB with associated first degree AV block RBBB with associated tachycardia RBBB Causes An atrial septal defect is one possible cause of a right bundle branch block. In addition, a right bundle branch block may also result from Brugada syndrome, right ventricular hypertrophy, pulmonary embolism, ischaemic heart disease, rheumatic heart disease, myocarditis, cardiomyopathy or hypertension. Epidemiology Prevalence of RBBB increases with age. Treatment The underlying condition may be treated by medications to control hypertension or diabetes, if they are the primary underlying cause. If coronary arteries are blocked, an invasive coronary angioplasty may relieve the impending RBBB. See also Bundle branch block Left bundle branch block References Jump up ^ `` Conduction Blocks 2006 KCUMB ''. Retrieved 2009 - 01 - 20. Jump up ^ Da Costa D, Brady WJ, Edhouse J ( March 2002 ). `` Bradycardias and atrioventricular conduction block ''. BMJ. 324 ( 7336 ) : 535 -- 8. doi : 10.1136 / bmj. 324.7336. 535. PMC 1122450. PMID 11872557. Jump up ^ `` Lesson VI - ECG Conduction Abnormalities ''. Retrieved 2009 - 01 - 07. Jump up ^ Goldman, Lee ( 2011 ). Goldman 's Cecil Medicine ( 24th ed. ). Philadelphia : Elsevier Saunders. pp. 400 -- 401. ISBN 1437727883. Jump up ^ `` Right Bundle Branch Block ''. www.symptoma.com. Retrieved 2015 - 08 - 13. Cardiovascular disease ( heart ) ( I00 -- I52, 390 -- 429 ) Ischaemic Coronary disease Coronary artery disease ( CAD ) Coronary artery aneurysm Spontaneous coronary artery dissection ( SCAD ) Coronary thrombosis Coronary vasospasm Myocardial bridge Active ischemia Angina pectoris Prinzmetal 's angina Stable angina Acute coronary syndrome Myocardial infarction Unstable angina Sequelae hours Hibernating myocardium Myocardial stunning days Myocardial rupture weeks Aneurysm of heart / Ventricular aneurysm Dressler syndrome Layers Pericardium Pericarditis Acute Chronic / Constrictive Pericardial effusion Cardiac tamponade Hemopericardium Myocardium Myocarditis Chagas disease Cardiomyopathy Dilated Alcoholic Hypertrophic Restrictive Loeffler endocarditis Cardiac amyloidosis Endocardial fibroelastosis Arrhythmogenic right ventricular dysplasia Endocardium / valves Endocarditis infective endocarditis Subacute bacterial endocarditis non-infective endocarditis Libman -- Sacks endocarditis Nonbacterial thrombotic endocarditis Valves mitral regurgitation prolapse stenosis aortic stenosis insufficiency tricuspid stenosis insufficiency pulmonary stenosis insufficiency Conduction / arrhythmia Bradycardia Sinus bradycardia Sick sinus syndrome Heart block : Sinoatrial AV 1 ° 2 ° 3 ° Intraventricular Bundle branch block Right Left Left anterior fascicle Left posterior fascicle Bifascicular Trifascicular Adams -- Stokes syndrome Tachycardia ( paroxysmal and sinus ) Supraventricular Atrial Multifocal Junctional AV nodal reentrant Junctional ectopic Ventricular Accelerated idioventricular rhythm Catecholaminergic polymorphic Torsades de pointes Premature contraction Atrial Junctional Ventricular Pre-excitation syndrome Lown -- Ganong -- Levine Wolff -- Parkinson -- White Flutter / fibrillation Atrial flutter Ventricular flutter Atrial fibrillation Familial Ventricular fibrillation Pacemaker Ectopic pacemaker / Ectopic beat Multifocal atrial tachycardia Pacemaker syndrome Parasystole Wandering pacemaker Long QT syndrome Andersen -- Tawil Jervell and Lange - Nielsen Romano -- Ward Cardiac arrest Sudden cardiac death Asystole Pulseless electrical activity Sinoatrial arrest Other / ungrouped hexaxial reference system Right axis deviation Left axis deviation QT Short QT syndrome T wave alternans ST Osborn wave ST elevation ST depression Strain pattern Cardiomegaly Ventricular hypertrophy Left Right / Cor pulmonale Atrial enlargement Left Right Other Cardiac fibrosis Heart failure Diastolic heart failure Cardiac asthma Rheumatic fever Retrieved from `` https://en.wikipedia.org/w/index.php?title=Right_bundle_branch_block&oldid=813071526 '' Categories : Cardiac arrhythmia Hidden categories : Infobox medical condition Talk Contents About Wikipedia Azərbaycanca Deutsch Español Français Bahasa Indonesia Italiano עברית 日本 語 Polski Português Українська 中文 Edit links This page was last edited on 1 December 2017, at 16 : 05. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what is a right bundle branch block in the heart
Answer: a heart block in the electrical conduction system