Left Atrial Tachycardia After Atrial Fibrillation Ablation: Can Magnetic Resonance Imaging Assist the Ablation?

Abstract We present a case of a magnetic resonance imaging-assisted ablation of an atrial tachycardia in a patient with previous atrial fibrillation ablation. A 3-D reconstruction of the delayed-enhanced cardiac magnetic resonance (CMR; CMR model) was created to identify previous ablation lesions and gaps. Multiple gaps around right-sided pulmonary veins were observed. The activation map identified a dual-loop re-entry around both right-sided pulmonary veins, confirming that the substrate identified using delayed-enhanced CMR was critical to sustain the tachycardia. Ablation at this site converted to sinus rhythm. The present case shows the usefulness of delayed-enhanced CMR substrate characterization to complement activation mapping of the tachycardia and more accurately define the anatomical circuit.