Management of New-Onset Right Bundle Branch Block

Evaluation and Diagnosis

An electrocardiogram is recommended as the first step to exclude structural heart disease in patients with newly detected right bundle branch block (RBBB) 1
Ambulatory electrocardiographic monitoring is useful in symptomatic patients to detect intermittent atrioventricular block and establish a symptom-rhythm correlation 1
A stress test with imaging may be considered in asymptomatic patients when coronary artery disease is suspected 1
The American College of Cardiology recommends an initial evaluation to exclude underlying cardiac disease in patients with RBBB 1

RBBB associated with first-degree atrioventricular block is considered a risk factor requiring closer monitoring 2, 3
RBBB associated with left anterior or posterior hemiblock (bifascicular block) is considered a risk factor requiring closer monitoring 2, 3
RBBB occurring after a procedure such as TAVI (transcatheter aortic valve implantation) is considered a risk factor requiring closer monitoring 4, 5
RBBB associated with symptoms such as syncope or presyncope is considered a risk factor requiring closer monitoring 4
The American College of Cardiology recommends closer monitoring for patients with RBBB and associated risk factors 2, 3

For asymptomatic patients with RBBB and no underlying cardiac disease, simple clinical surveillance without specific intervention is recommended (Class IIb according to ACC/AHA) 2, 3
For patients with RBBB and bifascicular block, close monitoring is recommended due to the increased risk of progression to complete heart block 2
For patients with RBBB and first-degree atrioventricular block, close monitoring is recommended (Class IIa) 2, 3
For patients with RBBB in the context of acute coronary syndrome, close monitoring is recommended as more than 50% of patients with acute chest pain and RBBB will eventually have a diagnosis other than myocardial infarction 6
For patients with RBBB after TAVI, close monitoring is recommended due to the increased risk of needing a permanent pacemaker and increased late mortality 4, 5
The American College of Cardiology recommends a permanent pacemaker for patients with advanced atrioventricular block documented 4

For patients with RBBB and additional conduction abnormalities, closer cardiological follow-up with regular evaluation of conduction disorder progression is recommended 2, 3
For patients with RBBB after TAVI, close monitoring during hospitalization and close follow-up after discharge is recommended 4, 5

The American College of Cardiology recommends echocardiography as the first step to identify structural cardiac abnormalities, including cardiomyopathy, valvular disease, congenital anomalies, or infiltrative processes that may underlie the conduction disturbance, in patients with RBBB who have increased risk of left ventricular systolic dysfunction compared to those with normal ECGs 7

The American College of Cardiology recommends permanent pacing for syncope with RBBB and HV interval ≥70 ms or infranodal block at EPS, as well as for alternating bundle branch block, which carries high risk of rapid progression to complete AV block 7

The American College of Cardiology suggests recording duration may vary from 24-72 hours to event monitors or implantable loop recorders depending on symptom frequency, and electrophysiology study (EPS) is reasonable when symptoms suggest intermittent bradycardia, as a prolonged HV interval ≥70 ms predicts higher risk for complete heart block 7