Answer

Pacemaker-mediated tachycardia (PMT) with ventricular pacing at a rate of 110 bpm (programmed maximal track rate): A cardiologist was consulted, and the PMT was terminated by applying a magnet. The pacemaker was reprogrammed to extend the postventricular atrial refractory rate (PVARP) to prevent further episodes of PMT.

The ECG is from Image 6 of the eMedicine article Pacemaker Failure. Available at: http://www.emedicine.com/med/topic1704.htm.

BACKGROUND

A 78-year-old man presents to the emergency department with a sudden onset of palpitations and dizziness. He has a history of well-controlled hypertension. He denies any chest pain; a pacemaker was inserted 2 weeks ago to treat a complete heart block.

Hint

His pulse is 110 beats per minute (bpm), and his blood pressure is 150/95 mm Hg. See the pacemaker spikes before QRS complex.

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