Acute anterior myocardial infarction and appearance of a left bundle branch block

Patient

67-year-old man, smoker with no significant cardiovascular history, hospitalized for chest pain since the past 6 hours;

Trace

Sinus rhythm, normal PR interval; complete left bundle branch block pattern with wide QRS, delayed intrinsicoid deflection in V6, exclusive positive deflection in V6, QS pattern in V1, V2 with no delay in intrinsicoid deflection, left axis; repolarization disorders are substantial with elevation from V1 to V4; positive Sgarbossa and Smith criteria in V2-V3 (ST elevation of 5 or 6 mm and S wave of 8 or 10 mm; ratio > 0.25);

Trace

The combination of typical chest pain and ECG pattern led to an emergency coronary angiography which showed proximal LAD thrombosis treated with thromboaspiration, angioplasty and stent placement; an ultrasound performed the next day revealed a left ventricular ejection fraction of 30%; the ECG on lead II showed a regression of the elevation with T-wave inversion in the anteroseptoapical territory; negative Sgarbossa and Smith criteria;

Exergue

The management of a patient with chest pain and left bundle branch block is problematic given the frequent difficulty in determining the age of the conduction disorder.