This is a narrow complex tachycardia with a rate of 124 beats/min. The QRS morphology and axis are normal. The QTc is prolonged, at 529 ms (normal, 390-450 ms for men). The underlying P waves appear ...

This is a narrow QRS complex tachycardia with a very fast heart rate (about 250 beats per minute). It is quite difficult to indentify any P wave activity to determine the exact etiology. Most commonly ...

A 35-year-old woman presents to the emergency department with palpitations for 2 hours. She states that she has intermittently had palpitations for years, but always lasting for minutes only. These ...