This rhythm strip was taken from a 41-year-old male with lymphoma. He had a 5-day history of substernal chest pain, which was increased by lying down and decreased by sitting up and leaning forward.

Is there a simple way to differentiate a supraventricular tachycardia from a ventricular, wide QRS tachycardia on a rhythm strip? The simplest initial approach is to look at the lead with the most ...