Incessant atrial tachycardia associated to atrial septal aneurysm treated by pulsed field ablation

Figures

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  Figure 1. Transesophageal echocardiogram images of the patient, in short-axis view (A) and bicaval view (B), obtained at different times, demonstrating a significant atrial septal aneurysm (arrows) with motion directed toward both the right atrium (A) and the left atrium (B).

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  Figure 2. A: Twelve-lead electrocardiogram recorded during the tachycardia episode. B: Intracardiac electrograms of the tachycardia recorded using a decapolar catheter positioned in the coronary sinus. CS5 corresponds to the proximal bipole of the catheter, while CS1 corresponds to the distal bipole. The CS4 bipole is positioned at the ostium of the coronary sinus. These recordings demonstrate a 2:1 atrial tachycardia with a right to left atrial activation sequence. C: Tachycardia activation mapping demonstrating a centrifugal (focal) activation pattern, originating from the region corresponding to the atrial septal aneurysm.

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  Figure 3. Tachycardia interruption by traumatic local nonpropagated ectopies during Orion catheter placement inside the atrial septal aneurysm (ASA). A to G correspond to the Orion catheter leads. SC identifies coronary sinus electrograms from proximal (SCp) to distal (SCd) leads. The final 4 cycles of the tachycardia, as demonstrated in the electrograms of the coronary sinus, are shown to have a cycle length of 240 ms. The sequence of events displayed by the Orion catheter electrograms, best observed by the spline H (purple), is distinct and recorded at the moment the catheter is placed into the ASA. It is noteworthy that the fifth and sixth electrograms represent local electrical depolarizations within the ASA caused by mechanical trauma, resulting in regional cycle length shortening and termination of the tachycardia without affecting the corresponding atrial cycle. These findings confirm the regional nature of the tachycardia.

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  Figure 4. High-definition voltage maps of the atrial septal aneurysm (ASA) obtained with the Orion catheter before (A) and after pulsed field ablation (B) under proximal coronary sinus stimulation. The gray tags in (A) represent the shortest observed distance between the anterior border of the ASA and the first atrioventricular junction site where His potential was identified. Panels (C) and (D) show images acquired in the left anterior oblique projection during contrast injection with the pulsed field ablation catheter positioned inside the ASA.