Electrocardiographic Predictors of Mortality in Acute Anterior Wall Myocardial Infarction With Right Bundle Branch Block and Right Precordial Q-Waves (qRBBB)

Abstract

Background: Published data on the clinical, electrocardiographic, and angiographic profile of acute anterior-wall ST-elevation myocardial infarction (STEMI) with right bundle branch block with q in leads V1, V2 (qRBBB) are scarce. The aim of this study was to estimate the incidence of short-term mortality and in-hospital complications in acute qRBBB STEMI and identify the electrocardiographic (ECG) predictors of a poor outcome.

Methods: We conducted a single-centre retrospective study among the patients with acute anterior-wall STEMI and qRBBB pattern on ECG. All relevant clinical and treatment data were collected from the electronic medical records. All the ECGs taken during the index hospitalization were subjected to detailed analysis.

Results: Among the 272 qRBBB patients included in the study, 64% had thrombolysis in myocardial infarction (TIMI) risk score of ≥6, and 41% were in Killip class III or IV at the time of presentation. The in-hospital mortality rate was 42.6%. There was a high incidence of ventricular tachyarrhythmias (12%), complete heart block (13%), heart failure (69%), and cardiogenic shock (52%). Extreme deviation of mean QRS axis to the right (180 to 269 degrees) in the baseline ECG was associated with high in-hospital mortality (odds ratio: 13.43; 95% confidence interval: 1.48-122.03; P = 0.021).

Conclusions: Acute qRBBB myocardial infarction is a sinister form of acute coronary syndrome that entails high in-hospital mortality and morbidity, necessitating early recognition and prompt institution of reperfusion therapy. Extreme deviation of QRS axis to the right (180 to 269 degrees) is a significant electrocardiographic predictor of in-hospital mortality.