Pacemaker‐Mediated Bigeminy: What Is the Mechanism?

Ventricular Pacing in Pacemaker Bigeminy to Rule in/out Truncated Pacemaker-mediated Tachycardia

“…Differential diagnoses of such bigeminy have been attributed to various causes such as premature atrial contractions, oversensing the T wave or the QRS complex, dual AV nodal physiology, and retrograde atrial depolarization. 1, 2 T wave oversensing was ruled out as there was no continuation of further ventricular events following the second T wave in the bigeminy complex. R wave oversensing was also not possible because the R wave to the next R was 400 ms, which was far more than the set sensed AV delay of 135 ms (Figure 2(b)).…”