Atrial flutter RA recording

Atrial flutter which is inapparent in lead I (upper panel); suggested by prominent negativity in lead II (arrows, middle panel), which could also represent biphasic T waves; and documented by right atrial recording, which shows prominent negative deflections (arrows, lower panel).

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.