Edit concept Create issue ticket

Right Bundle Branch Block


Presentation

In the majority of cases, right bundle branch block produces no symptoms of the heart condition. The more common sign and symptoms encountered in RBBB includes:

Acute Abdomen
  • After urgent surgery according to the acute abdomen, she was referred to intensive care unit (ICU) of the emergency unit as she was intubated.[ncbi.nlm.nih.gov]
Heart Disease
  • Any of the components of the left bundle can be involved, and this complex interventricular conduction abnormality has previously been described in patients with underlying heart disease.[ncbi.nlm.nih.gov]
  • In the absence of structural heart disease, ventricular tachycardia is known as idiopathic ventricular tachycardia and carries a good prognosis.[ncbi.nlm.nih.gov]
  • Right bundle branch block is associated with an increased risk of mortality in general population and patients with heart disease.[ncbi.nlm.nih.gov]
  • […] conducting system (Lenegre disease) Hyperkalaemia Digoxin toxicity Ischaemic heart disease Rheumatic heart disease Right ventricular hypertrophy (cor pulmonale) Pulmonary embolus Cardiomyopathy Myocarditis Congenital heart disease (e.g.[medicalexamprep.co.uk]
  • Isolated right bundle branch block is generally regarded as a benign finding in the absence of underlying structural heart disease.[ncbi.nlm.nih.gov]

Workup

The following tests and diagnostic modalities are implored in the diagnosis of right bundle branch blocks:

  • Electrocardiography (ECG): This makes use of multiple electrodes place on the chest of the patient to record the cardiac electrical activities. Often times, RBBB is an incidental ECG finding while another cardiac disease is being worked up.
  • Echocardiogram: The use of a two dimensional echocardiograph can elucidate a detailed view of the cardiac structures. This can demonstrate the actual movement of the heart wall, muscles and valves. The discovery of an atrial septal defect (ASD) or ventricular septal defect (VSD) can be facilitated by the echocardiogram. 
  • Holter monitoring: A continuous ambulatory monitoring of the cardiac electrical activity may be indicated in post-operative cases who undergone VSD or tetralogy of Fallot cardiac repair [9].
Wide QRS Complex
  • In a type I block with wide QRS complex ( 0.12sec), the block can be in the His-Purkinje system in 60-70% of the cases.[ncbi.nlm.nih.gov]
  • These are the criteria for multifocal atrial tachycardia MAT, also known as chaotic atrial rhythm,1 chaotic atrial tachycardia,2 and chaotic atrial mechanism.3 The wide QRS complexes 0.12 s with broad S waves in leads I, aVL, and the lateral precordial[ncbi.nlm.nih.gov]
  • Right bundle branch block As illustrated in the electrocardiogram below, right bundle branch block presents with delayed activation of the right ventricle, leading to a wide QRS complex lasting greater than 0.12 seconds.[meds.queensu.ca]
  • So we have a supraventricular rhythm with wide QRS complexes. Once you have determined that a supraventricular rhythm is wide you should go to lead V1 and see if you can classify it as a right or left bundle branch block.[ems12lead.com]
  • In both cases, there is a wide QRS complex. Management Generally, you can just leave it but if the bundle branch block is severe, a pacemaker will need to be fitted.[medrevise.co.uk]
T Wave Inversion
  • Delayed activation of the right ventricle also gives rise to secondary repolarization abnormalities, with ST depression and T wave inversion in the right precordial leads.[lifeinthefastlane.com]
  • wave inversion in the anterior leads - There may be an extra R wave in the anterior leads ( R'), or there may just be a broad slurred QRS. - The depolarization of the right ventricle is delayed - The left ventricle activates normally: the early part of[derangedphysiology.com]
  • wave inversions and ST segment depression are normal in leads V1 to V3 in the presence of a right bundle branch block; thus, myocardial ischemia technically cannot be easily determined in these leads.[healio.com]
  • It also causes secondary repolarisation abnormalities, with T wave inversion and ST depression being seen in the right praecordial leads. Secondary T wave changes are also a normal finding in RBBB.[medicalexamprep.co.uk]
  • As shown in Figure 1, the positive QRS complex in V1 is followed by negative ST-T segment with ST-segment depression and T-wave inversion. Similar changes are typically seen in V2.[ecgwaves.com]
Electrocardiogram Change
  • Electrocardiogram changes are common and precede the development of hypotension and neurological deterioration, therefore close watch on ECG monitoring is strongly recommended in the patients of TCAs poisoning. References 1.[mjdrdypu.org]

Treatment

Patients presenting with asymptomatic heart block or a first degree heart block do not require any treatment. However, in RBBB presenting with an underlying condition, treatment may be necessary to control the disorder.

These may require the intake of medications to control hypertension or diabetes as the primary underlying cause. An invasive coronary angioplasty may be done to repair the blocked coronary arteries to relieve the impending RBBB.

In patients presenting with recurrent fainting, the implantation of an internal pacemaker may prevent further fainting spells. The pacemaker will generate regular electric impulses to regulate heart rhythm and ensure an optimal cardiac pumping.

Prognosis

Some forms of naturally occurring right bundle branch block like familial bundle branch block has a good prognostic outcome. Post VSD repair scarring of heart tissues may present eminently of electrophysiologic studies but may prove to be benign in the long run. However, cardiac scarring due to the tetralogy of Fallot repair have increases risk of cardiac arrhythmia and sudden cardiac death.

ECG finding of right bundle branch block associated with the Brugada syndrome [6], arrhythmogenic right ventricular cardiomyopathy (ARVC) [7], and Kearne-Sayre syndrome are also at high risk with sudden cardiac death and arrhythmia; thus, carry a grim prognosis in patients [8].

Complications

The following cardiac conditions are common complications associated with the right bundle branch block:

  • Symptomatic bradycardia: The right bundle branch block may consequently slow down the rate of conduction and heart rate causing significant symptoms requiring pacemaker installation in most patients.
  • Sudden cardiac death occurs when the bundle branch completely fails to transmit electrical impulses and results to cardiac arrest.
  • Misdiagnosis of cardiac diseases: The ongoing RBBB may distort or complicate ECG readings of other heart disorders like myocardial infarction causing a delay in management and an increase in the mortality and morbidity rate in patients.

Etiology

The following medical conditions can directly cause right bundle branch block in patients:

Epidemiology

In the United States, the most common cause of right bundle branch block among children is post-surgical repair scarring of ventricular septal defect (VSD). The incidence rate for RBBB in the surgical repair of VSD alone is 25-81% and up to 60-100% after surgical cardiac repair in tetralogy of Fallot.

The long term effect of surgically induced RBBB in VSD repair has no major hemodynamic significance on the patient. However, in patients who underwent repair of the tetralogy of Fallot may consequently have QRS prolongation of up to 180 milliseconds and may carry some risk for arrhythmia and sudden cardiac death.

A number of trained athletes my present with complete and incomplete RBBB by voltage that points to an innocent physiologic cardiac remodeling phenomenon of the right atrium [4].

Sex distribution
Age distribution

Pathophysiology

The basic pathophysiological defect in right bundle branch block is primarily due to the non-conduction of electrical impulses from the bundle of His to right bundle branch tracks.

In the advent that the left bundle branch conducts normally, right ventricular depolarization becomes significantly discordant with the left ventricle. This ventricular depolarization mismatch gives out the characteristic electrocardiograph (ECG) reading. There are rare cases of exercise induced right bundle branch block which are presenting similarly but are clinically benign [5].

Prevention

Not all right bundle branch block conditions are preventable. However, RBBB can effectively be prevented by keeping the heart healthy to avert cardiac conditions that results to RBBB. The following useful tips can reduce the risk for coronary artery disease that can lead to RBBB:

  • A regular healthy diet that is low on cholesterols and fats.
  • Regular cardio exercise in up to 30 minutes minimum per week.
  • Maintaining an ideal body weight.
  • Quitting cigarette smoking.
  • Control of hypertension with maintenance antihypertensive medications.
  • Active control of diabetes.
  • Prompt treatment of hypercholesterolemia and triclyceridemia.
  • Regular follow-up with cardiologist for post-operative cardiac patients [10].

Summary

Right bundle branch block (RBBB) refers to a clinical condition wherein the transmission of impulses  towards the right ventricle is significantly delayed. The blockage of the right sided electrical pathway can make it difficult for the heart to pump efficiently. There are no specific treatment for RBBB and all management is geared towards the resolution of the underlying cardiac disease.

Patient Information

Definition

Right bundle branch block (RBBB) is clinically defined as a significant delay in the transmission of electrical impulse from the AV node to the right bundle branch of the heart.

Cause

Atrial septal defect, myocardial infarction, recent cardiac surgery, infectious myocarditis, pulmonary embolism, and familial bundle branch block may lead to this disorder.

Symptoms

Fainting, near fainting, chronic fatigue, and palpitations are common symptoms of RBBB.

Diagnosis

Electrocardiography, echocardiography, and Holter monitoring may be necessary to diagnose the condition.

Treatment and follow-up

Management of underlying cardiac cause and pacemaker installation are common treatment options.

References

Article

  1. Stephan E, Chedid R, Loiselet J, Bouvagnet P. Clinical and molecular genetics of familial bundle branch block related to chromosome 19 [in French]. Arch Mal Coeur Vaiss. Dec 1998; 91(12):1465-74.
  2. Finnish Medical Society Duodecim. Myocardial infarction. In: EBM Guidelines. Evidence-Based Medicine. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2008 Apr 2.
  3. Diogenes MS, Succi RC, Machado DM, et al. Cardiac longitudinal study of children perinatally exposed to human immunodeficiency virus type 1 [in Portuguese]. Arq Bras Cardiol. Oct 2005; 85(4):233-40.
  4. Kim JH, Noseworthy PA, McCarty D, Yared K, Weiner R. Significance of electrocardiographic right bundle branch block in trained athletes. Am J Cardiol. 2011; 107(7):1083-9 
  5. Stein R, Nguyen P, Abella J, Olson H, Myers J, Froelicher V. Prevalence and prognostic significance of exercise-induced right bundle branch block. Am J Cardiol. Mar 1 2010; 105(5):677-80.
  6. Deschenes I, Baroudi G, Berthet M, et al. Electrophysiological characterization of SCN5A mutations causing long QT (E1784K) and Brugada (R1512W and R1432G) syndromes. Cardiovasc Res. Apr 2000; 46(1):55-65.
  7. Marcus FI, McKenna WJ, Sherrill D, Basso C, Bauce B, Bluemke DA, et al. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia: proposed modification of the Task Force Criteria. Eur Heart J. Apr 2010; 31(7):806-14.
  8. van Beynum I, Morava E, Taher M, Rodenburg RJ, Karteszi J, Toth K, et al. Cardiac arrest in kearns-sayre syndrome. JIMD Rep. 2012; 2:7-10.
  9. Jain R, Dalal D, Daly A, et al. Electrocardiographic features of arrhythmogenic right ventricular dysplasia.Circulation. Aug 11 2009; 120(6):477-87.
  10. Hui W, Slorach C, Dragulescu A, Mertens L, Bijnens B, Friedberg MK. Mechanisms of Right Ventricular Electromechanical Dyssynchrony and Mechanical Inefficiency in Children After Repair of Tetralogy of Fallot.Circ Cardiovasc Imaging. May 1 2014

Ask Question

5000 Characters left Format the text using: # Heading, **bold**, _italic_. HTML code is not allowed.
By publishing this question you agree to the TOS and Privacy policy.
• Use a precise title for your question.
• Ask a specific question and provide age, sex, symptoms, type and duration of treatment.
• Respect your own and other people's privacy, never post full names or contact information.
• Inappropriate questions will be deleted.
• In urgent cases contact a physician, visit a hospital or call an emergency service!
Last updated: 2018-06-21 22:02