right bundle branch block

An incomplete right bundle branch block (IRBBB) is a conduction abnormality in the right bundle branch block. While a complete RBBB has a QRS duration of 120 ms or more, an incomplete RBBB has a wave duration between 100 and 120 ms. It has a relatively high prevalence, a study conducted on young Swiss military conscripts with a mean age of 19 years found a prevalence of 13.5%.{{cite journal | vauthors = Kobza R, Cuculi F, Abächerli R, Toggweiler S, Suter Y, Frey F, Schmid JJ, Erne P | title = Twelve-lead electrocardiography in the young: physiologic and pathologic abnormalities | journal = Heart Rhythm | volume = 9 | issue = 12 | pages = 2018–2022 | date = December 2012 | pmid = 23102624 | doi = 10.1016/j.hrthm.2012.08.034 }} It affects patients of all ages, more commonly males and athletes, however it is not always a benign finding. Therefore, if abnormalities are detected on the physical exam, further testing should be done to exclude heart disease.{{cite journal | vauthors = Floria M, Parteni N, Neagu AI, Sascau RA, Statescu C, Tanase DM | title = Incomplete right bundle branch block: Challenges in electrocardiogram diagnosis | journal = Anatolian Journal of Cardiology | volume = 25 | issue = 6 | pages = 380–384 | date = June 2021 | pmid = 34100724 | pmc = 8210929 | doi = 10.5152/AnatolJCardiol.2021.84375 | s2cid = 235368614 }}

There is no consensus in the literature regarding criteria for diagnosis. However, according to the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society (AHA/ACCF/HRS) it is defined by the following finding in adults:

1. QRS wave duration between 100 and 120 ms.
2. rsr, rsR, or rSR in leads V1 or V2.
3. S wave of longer duration than R wave or greater than 40 ms in leads I and V6.
4. Normal R wave peak time in both V5 and V6, but greater than 50 ms in V1.

The first three criteria are needed for diagnosis. The fourth is needed when a pure dominant R waver is present on V1.

Common causes include normal variation, changes in bundle branch structure - such as mechanical stretching, chest trauma, right ventricular hypertrophy or strain, congenital heart disease such as atrial septal defect, and ischemic heart disease. {{cite book| vauthors = Goldman L |title=Goldman's Cecil Medicine|url=https://archive.org/details/goldmanscecilmed00mdle|url-access=limited|publisher=Elsevier Saunders|location=Philadelphia|year=2011|isbn=978-1-4377-2788-3|pages=[https://archive.org/details/goldmanscecilmed00mdle/page/n2559 400]–401|edition=24th}} In addition, a right bundle branch block may also result from Brugada syndrome, Chagas disease,{{cite web |title=Chagas Disease: What U.S. Clinicians Need to Know |url=https://www.cdc.gov/parasites/cme/chagas/lesson_2/8.html |website=Centers for Disease Control and Prevention |publisher=CDC |access-date=3 October 2023}}{{cite journal | vauthors = Rojas LZ, Glisic M, Pletsch-Borba L, Echeverría LE, Bramer WM, Bano A, Stringa N, Zaciragic A, Kraja B, Asllanaj E, Chowdhury R, Morillo CA, Rueda-Ochoa OL, Franco OH, Muka T | title = Electrocardiographic abnormalities in Chagas disease in the general population: A systematic review and meta-analysis | journal = PLoS Neglected Tropical Diseases | volume = 12 | issue = 6 | pages = e0006567 | date = June 2018 | pmid = 29897909 | pmc = 5999094 | doi = 10.1371/journal.pntd.0006567 | doi-access = free }} pulmonary embolism, rheumatic heart disease, myocarditis, cardiomyopathy, or hypertension.{{cite journal | vauthors = Ikeda T | title = Right Bundle Branch Block: Current Considerations | journal = Current Cardiology Reviews | volume = 17 | issue = 1 | pages = 24–30 | date = January 2021 | pmid = 32640959 | pmc = 8142372 | doi = 10.2174/1573403X16666200708111553 }}

Causes for incomplete right bundle branch block (IRBBB) often involve exercise-induced right ventricular remodeling, increased right ventricular (RV) free wall thickness, especially in athletes due to prolonged endurance exercise.{{cite journal | vauthors = Floria M, Parteni N, Neagu AI, Sascau RA, Statescu C, Tanase DM | title = Incomplete right bundle branch block: Challenges in electrocardiogram diagnosis | journal = Anatolian Journal of Cardiology | volume = 25 | issue = 6 | pages = 380–384 | date = June 2021 | pmid = 34100724 | pmc = 8210929 | doi = 10.5152/AnatolJCardiol.2021.84375 | s2cid = 235368614 }}

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| image1 = Reizleitungssystem 12.png

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| caption1 = Normal electrical conduction system of the heart (Schematic). All myocardial segments are excited almost simultaneously (purple staining). {{ordered list |Sinoatrial node |Atrioventricular node}}

| image2 = Reizleitungssystem RSB.png

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| caption2 = 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).

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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).{{cite web | vauthors = Yanowitz FG | date = | publisher = University of Utah School of Medicine |url= http://library.med.utah.edu/kw/ecg/ecg_outline/Lesson6/index.html#RBBB | archive-url = https://web.archive.org/web/20080126080609/http://library.med.utah.edu/kw/ecg/ecg_outline/Lesson6/index.html | archive-date = 26 January 2008 |title= Lesson VI - ECG Conduction Abnormalities |access-date=2009-01-07}}
• There should be a terminal R wave in lead V₁ (often called "R prime," and denoted by R, rR', rsR', rSR', or qR).
• There must be a prolonged S wave in leads I and V₆ (sometimes referred to as a "slurred" S wave).

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.{{cn|date=February 2021}}

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.{{Cite web|title = Right Bundle Branch Block|url = https://www.symptoma.com/en/info/right-bundle-branch-block |website = Symptoma |access-date = 2015-08-13}}

Prevalence of RBBB increases with age due to changes in the heart's conduction system. It's estimated up to 11.3% of the population by the age of 80 have RBBB.{{cite book | vauthors = Harkness WT, Hicks M | chapter = Right Bundle Branch Block |date=2022 | chapter-url= http://www.ncbi.nlm.nih.gov/books/NBK507872/| title = StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=29939649|access-date=2022-02-24}}

File:RBBB with first degree AV block.jpg|RBBB with associated first degree AV block

File:Cardiogram indicating right bundle branch block with tachycardia.jpg|RBBB with associated tachycardia

File:Cardiogram indicating right bundle branch block.jpg|RBBB

• Bundle branch block
• Intraventricular block
• Left bundle branch block

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{{Medical resources

| DiseasesDB = 11620

| ICD10 = {{ICD10|I|45|1|i|30}}

| ICD9 = {{ICD9|426.4}}

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| eMedicineSubj = ped

| eMedicineTopic = 2500

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{{Circulatory system pathology}}

Category:Cardiac arrhythmia

fr:Bloc de branche#Bloc de branche droit