ECG changes in atrial fibrillation do not include: March 2007

Ans. C: Tall P waves A conclusive indication of AF is the absence of P waves on an electrocardiogram (ECG). It can be distinguished from atrial flutter, which is a more organized electrical circuit usually in the right atrium that produces characteristic saw-toothed p-waves on the ECG; in atrial flutter, the discharges circulate rapidly at a rate of 260300 beats per minute (bpm) around the atrium; in AF, there is no regularity of this kind at all. Characteristic findings are the absence of P waves, with unorganized electrical activity in their place, and irregularity of R-R interval due to irregular conduction of impulses to the ventricle