The ECG shows normal sinus rhythm with prominent P waves in II-III-AVF. The QRS duration is about 0.1 sec with a frontal plane axis of about –60° and small R waves in the inferior leads. The QRS ...

The correct diagnosis is atrial flutter with 2:1 atrioventricular (AV) block (Figure 2). Figure 2. Courtesy of Philip J. Podrid, MD. The rhythm is regular at a rate of 150 beats/min. The QRS complex ...