A 76-year-old woman with documented non-ischemic cardiomyopathy is brought to the Emergency Department with palpitation, severe dyspnea and weakness of 1 1/2 hour duration:

• Wide QRS tachycardia, 150/min 
• Most likely VENTRICULAR TACHYCARDIA

In favour of the diagnosis of ventricular tachycardia:

• Onset of a wide QRS tachycardia and severe symptoms in a   patient with known cardiomyopathy
• QRS duration =175 msec (>140 msec)
• RBBB pattern with broad monophasic R waves in V1

DC cardioversion is carried out successfully. The symptoms of the patient quickly improve:

• Sinus rhythm with sinus arrhythmia – Heart rate 64/min
• First degree AV block
• Nonspecific intraventricular block