Deceptive intracardiac electrograms during an ICD interrogation. A clinical challenge.

We present a case of a patient with significant structural heart disease from previous cardiac surgeries who presented for an electrophysiology study and radiofrequency ablation. The case highlights the significance of intra-atrial conduction delays in such patients and potential pitfalls it can present while interpreting intra-cardiac electrograms especially during implantable cardioverter defibrillator (ICD) interrogations.