The rhythm in Figure 1 has a subtle pattern—a narrow QRS complex with alternating short and long R-R intervals, resulting in paired QRS complexes. Careful observation of V1 in Figure 2 reveals tiny ...

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 ...

When atrial flutter is seen with such a slow ventricular response (in this case, 9:1 conduction), there is concern for underlying complete heart block should the patient be restored to normal sinus ...

Narrow QRS complexes occur regularly. This tracing suggests either atrial flutter or ventricular tachycardia. It is not atrial flutter, however. If it were, the QRS complexes occurring regularly would ...

Among the 77 patients assigned to undergo circumferential pulmonary-vein ablation, ablation was repeated because of recurrent atrial fibrillation in 26 percent of patients and atypical atrial flutter ...