Two hearts beating out of time: Mapping and ablation of concurrent atrial fibrillation and macroreentrant left atrial flutter in a transplanted heart

Figures

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  Figure 1. A: Preprocedure 12-lead electrocardiogram showing atrial flutter with 4:1 ventricular conduction and atypical atrial flutter waves seen maximally in leads V1 and V2. B: Intracardiac signal recording in atrial flutter with a distal-to-proximal coronary sinus (CS) activation pattern and cycle length of 216 ms (right-hand side of panel). We entrained the tachycardia by pacing from distal CS at 200 ms and demonstrated that we were driving the atrium with 1:1 conduction. CS activation was similar during pacing and tachycardia. The postpacing interval minus tachycardia cycle length was 8 ms. Similar findings were seen from the proximal CS, suggesting a macroreentrant circuit.

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  Figure 2. A 3D map of the left atrium (LA) in a left lateral orientation showing activation and voltage maps. The activation map shows a clockwise mitral isthmus–dependent atrial flutter in the anterior LA and disorganized signals in the posterior LA, representing atrial fibrillation. The dark blue area represents the left upper and lower pulmonary veins. The voltage map reveals a clear distinction in signal anterior to the pulmonary veins, representing the anastomosis between donor and recipient portions of the LA. Signals from the surface electrocardiogram, coronary sinus catheter, PentaRay catheter (Biosense Webster, CA) positioned in the posterior LA, and ablation catheter (positioned in the LA appendage) are shown.

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  Figure 3. A: A 3D map of the left atrium (LA) in left anterior oblique orientation showing a mitral isthmus–dependent flutter activation pattern displaying a mitral isthmus ablation lesion set (red dots marking impedance drop with range of 5–10 ohms). B: Activation map while pacing from left atrial appendage via the ablation catheter demonstrating mitral isthmus block at the site of ablation. C: Voltage map demonstrating attenuated signals following ablation (red) previously seen as normal (pink) in Figure 2 before ablation (range 0.2–0.5 mV). D: Intracardiac signals after ablation showing sinus rhythm restored in the donor heart (P wave visible on surface electrocardiogram, coronary sinus showing proximal-to-distal activation). PentaRay signals from the posterior native LA demonstrate that this area remained in atrial fibrillation in isolation from the donor heart.