A 62-year-old man presented to the emergency room with palpitations and dyspnea. The patient had a history of kidney disease and bicuspid aortic valve disease, with class III/IV heart failure and left ventricular dilatation and dysfunction (ejection fraction, 40%) but no history of palpitations, dizziness, or syncope. Physical examination on admission revealed blood pressure of 130/80 mmHg and no overt signs of heart failure. The admission ECG showed regular, wide-QRS tachycardia (Figure 1). Sinus rhythm was restored with electrical cardioversion (Figure 2).What is the most mechanism in this patient?

• 1.

  Monomorphic ventricular tachycardia due to myocardial reentry.

• 2.

  Monomorphic ventricular tachycardia due to bundle branch reentry.

• 3.

  Nodal reentrant tachycardia with right bundle branch block.

• 4.

  Preexcited tachycardia.

Figure 1

(0.26MB).

Figure 2

(0.24MB).

Suggest a solution to this ECG Contest at http://www.revespcardiol.org/es/electroreto/70/4. The answer will be published in the next issue (May 2017). #RetoECG.