Flecainide induced ST segment changes can mimic pathological ECG changes in patients undergoing exercise testing: A case report.

BACKGROUND: Flecainide, a class IC antiarrhythmic drug, is used frequently in patients with supraventricular arrhythmias, mostly atrial fibrillation, and less commonly for ventricular arrhythmias. With its strong affinity to sodium channels the cardiac cells it affects phase 0 of action potential leading conduction slowing, which reflected widening QRS, can also prolong PR interval. These unspecific electrocardiogram (ECG) changes may mimic myocardial ischaemia undergoing stress testing. The current case report reflects diagnostic difficulties arising from this phenomenon.