At times it is difficult to distinguish atrial fibrillation from atrial flutter on the ECG. This example shows coarse "fibrillatory waves" in the setting of atrial fibrillation. This are of varying ...

A 76-year-old woman with known ischemic cardiomyopathy, a left ventricular ejection fraction of 25%, and a previously inserted pacemaker presents to her cardiologist concerned that there is a problem ...

A 78-year-old man with a history of heart failure presents for routine follow-up 1 week after insertion of a pacemaker. As part of the evaluation, a 12-lead ECG is obtained. The correct diagnosis is ...

This ECG shows ventricular pacing. Note the pacer spike prior to each QRS complex, most apparent in leads V5 and V6. The P waves appear sinus in origin and have no association with the QRS complexes ...

(F) ECG rhythm strip reveals the initiation of electrical stimulation in the nonbeating heart at 60 bpm as evidenced by the consistent pacing spikes, followed by QRS for myocardial activation and T ...