Initial Management of Right Ventricular Conduction Delay
The initial approach to managing right ventricular conduction delay (RBBB) is to obtain a 12-lead ECG to confirm the diagnosis, assess for symptoms that temporally correlate with the conduction abnormality, and avoid permanent pacing in asymptomatic patients—which is considered harmful. 1
Diagnostic Confirmation
Obtain a 12-lead ECG to document the conduction pattern using the following diagnostic criteria: QRS duration ≥120 ms, rsr', rsR', rSR, or rarely qR pattern in leads V1 or V2, S wave duration greater than R wave or >40 ms in leads I and V6, and normal R peak time in leads V5 and V6 but >50 ms in lead V1. 1
Screen for structural heart disease on the ECG, though RBBB itself does not markedly increase the likelihood of underlying structural heart disease or left ventricular systolic dysfunction (unlike left bundle branch block). 1
Symptom Assessment and Risk Stratification
The critical decision point is whether the patient is symptomatic or asymptomatic:
Asymptomatic Patients with Isolated RBBB
Do NOT implant a permanent pacemaker in asymptomatic patients with isolated RBBB and 1:1 atrioventricular conduction—this is a Class III: Harm recommendation. 1
Avoid the pitfall of implanting pacemakers based solely on QRS duration, as this constitutes inappropriate therapy. 1
Symptomatic Patients (Syncope)
Proceed to electrophysiology study (EPS) to measure the HV interval in symptomatic patients with syncope and RBBB. 1
Implant a permanent pacemaker if the HV interval is ≥70 ms or if there is evidence of infranodal block (Class I recommendation). 1
Ensure symptoms temporally correlate with documented bradycardia before attributing them to the conduction delay—this is a common pitfall to avoid. 1
Screening for Structural Heart Disease
Order echocardiography selectively, not routinely:
Obtain echocardiography in patients with new onset RBBB in the setting of acute symptoms, associated symptoms suggesting heart failure, or concern for specific cardiomyopathies. 1
Remember that RBBB carries a much lower risk of structural heart disease compared to left bundle branch block, so routine echocardiography in asymptomatic patients is not indicated. 1
Special Populations
- Consider permanent pacing with defibrillator capability in patients with Kearns-Sayre syndrome and any conduction disorder, including RBBB, if meaningful survival >1 year is expected (Class IIa recommendation). 1
Key Clinical Pitfalls
Never assume RBBB indicates the same structural heart disease risk as left bundle branch block—the latter has a much stronger association with cardiomyopathy. 1
Do not pursue cardiac resynchronization therapy (CRT) in patients with RBBB, as this conduction pattern does not benefit from CRT even with QRS ≥150 ms, unlike left bundle branch block or intraventricular conduction delay. 2
Avoid attributing symptoms to RBBB without objective documentation of temporal correlation between symptoms and bradycardia or conduction abnormalities. 1