Interpreting the ECG in patients with chest pain and right bundle branch block: A case report

Area of Science:

• Cardiology
• Electrocardiography
• Emergency Medicine

Background:

• Right bundle branch block (RBBB) can alter electrocardiogram (ECG) morphology, potentially obscuring signs of acute myocardial infarction.
• Accurate and timely diagnosis of ST-elevation myocardial infarction (STEMI) is critical for initiating reperfusion therapy and improving patient survival.

Observation:

• A patient with RBBB presented with chest pain and ECG findings suggestive of, but not meeting criteria for, anterior STEMI.
• Initial ECG interpretation failed to identify STEMI due to the RBBB confounding standard voltage criteria.

Findings:

• Despite initial misinterpretation, subsequent angiography revealed severe left anterior descending artery stenosis.
• The patient experienced cardiac arrest, requiring resuscitation and pacemaker implantation with left bundle branch pacing.

Implications:

• This case underscores the limitations of current ECG voltage criteria for diagnosing anterior STEMI in the presence of RBBB.
• Highlights the need for revised diagnostic approaches or increased clinical suspicion in RBBB patients with ischemic symptoms.
• Emphasizes the importance of considering clinical presentation alongside ECG findings, especially in complex cases.