Wide QRS Complex Tachycardia

A 71-year-old man with a history of previous myocardial infarction was referred to our hospital for recurrent symptoms of palpitation and syncope. During an episode of palpitations, a 12-lead ECG (Figure 1) was obtained in the emergency room. The ECG shows a wide-QRS complex tachycardia at a rate of 167 bpm. The P waves are positive in lead II (↑) before each QRS complex, and the PR interval is 80 milliseconds. The QRS duration is prolonged with apparent slurring of the QRS upstoke, suggesting the possible presence of a delta wave. Are these features consistent with a diagnosis of atrial tachycardia with pre-excitation? However, the possibility of ventricular tachycardia (VT) also should be considered in our patient because of the old myocardial infarction. Therefore, the ECG diagnosis is challenging. What are the diagnosis and best management strategy for this patient? Gaopin Wang Renguang Liu Qinghua Chang, MD Wide QRS Complex Tachycardia