ECG evaluation in patients with pacemaker and suspected acute coronary syndrome: Which score should we apply?

BACKGROUND/PURPOSE: In patients with right ventricular pacing, the ECG shows a left bundle branch block (LBBB) pattern. There are several criteria to diagnose ST-elevation myocardial infarction (STEMI) in patients with LBBB. The aim of this study was to validate and compare Sgarbossa's with two new scores - Selvester's and Smith's - in this context.

METHODS: We identified pacemaker patients submitted to coronary angiography due to acute coronary syndrome. ECGs were analyzed by 2 blinded cardiologists. STEMI was defined according to angiographic and biochemical criteria. Sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS: Forty-three patients with ventricular pacing were included for analysis. STEMI was diagnosed in 26 patients (60%). The most sensitive score was Selvester's (38.5%; 95% CI: 20.2-59.4) while the most specific was Sgarbossa's (100%; 95% CI: 80.5-100).

CONCLUSIONS: The sequential application of these scores proved to be clinically useful in the context of STEMI.