An epicardial approach for ablation of relapsing atypical atrial flutter: Thinking outside the box

Figures

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  Figure 1. Tridimensional endocardial color-coded map characterization of the clinical atypical atrial flutter. A: Endocardial electrophysiological mapping using the CARTO3V 7.2 system portraying a macroreentrant tachycardia with an isthmus located in the anterior wall of the left atrium. B: Activation map after extensive endocardial ablation. C: Voltage map denoting extensive endocardial ablation.

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  Figure 2. CO2-mediated epicardial puncture. A: Catheterization of the coronary sinus (CS) and microcatheter puncture of a distal vein, providing access for CO2 delivery. B: Separation of parietal and visceral pleural leaflets of the pericardium by CO2. C: Sub-xiphoid puncture and guidewire progression to the pericardial cavity.

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  Figure 3. Anterior and lateral approach to epicardial atrial flutter ablation. A: Superior view of a tridimensional reconstruction of the left atrium with wall thickness distribution using the ADAS 3D system. An initial anterior approach targeting the maximum thickness zone—compatible with the passage of fibers belonging to the Bachmann bundle—was attempted (dark-gray arrows, dark-gray area). Because of the presence of reflections of the pericardium that precluded posterior catheter progression, the target line could not be completed. A lateral approach targeting the transverse sinus passing between the left atrial appendage (LAA) and the left superior pulmonary vein (LSPV) was performed (light red arrows, light red area). B: Schematic posterior view of the heart. Pericardial reflections of interest are depicted by the dotted lines. The transverse sinus is accessible laterally between the LPA, the LAA, and the LSVP. This structure is limited anteriorly by the PA and pericardial reflections and posteriorly by the pericardial reflections that cover the LSVP and the RSVP (which constitute the boundary between the transverse sinus and the oblique sinus). The lateral approach depicted in this…