Single-lead electrocardiogram (ECG) showing atrial fibrillation with minimally apparent atrial activity

F waves are not apparent in this lead, as the only finding suggestive of AF is the irregularly irrregular ventricular response.

AF: atrial fibrillation.

Courtesy of Morton Arnsdorf, MD.

Graphic 53988 Version 4.0

Normal rhythm strip

Normal rhythm strip in lead II. The PR interval is 0.15 sec and the QRS duration is 0.08 sec. Both the P and T waves are upright.

Courtesy of Morton F Arnsdorf, MD.

Graphic 59022 Version 3.0