Slow right atrial appendage tachycardia mimicking sinus rhythm

A 57-year-old man was referred for treatment of incessant regular palpitations. The 12-lead electrocardiogram (ECG) revealed a slow narrow QRS complex tachycardia with a cycle length of 680  ms (Panel A) and P-wave morphology similar to that recorded during sinus rhythm (Panel B). Electroanatomical mapping of the right atrium defined the earliest endocardial activation (white colour) to the apex of the right atrial appendage, where radiofrequency catheter ablation successfully terminated the focal arrhythmia (Panel C, right anterior oblique view, yellow dot). The activation map during sinus rhythm is shown inPanel D. Careful ECG analysis revealed negative P waves in leads V1 –V2 during tachycardia (Panel C, arrows), allowing electrocardiographic differentiation from sinus rhythm.
Source: Europace - Category: Cardiology Source Type: research