Tachyarrhythmias in Congenital Heart Diseases: From Ion Channels to Catheter Ablation

Figures

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  Figure 1. Cardiac remodeling and arrhythmia burden in congenital heart diseases. CHD, congenital heart disease; CV, cardiovascular.

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  Figure 2. Catheter ablation in congenital heart diseases, technological advances for challenging cases.

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  Figure 3. Transbaffle puncture in patients with D-TGA and atrial switch. (A) CT-scan images of a patient with Senning surgery in right anterior oblique 30° (left) and posteroanterior view (right) showing that the systemic venous atrium is surrounded by the pulmonary venous atrium. In another patient with Mustard surgery, after the merging of electroanatomical and CT-scan images, the optimal site for transbaffle puncture is located (white circle, (B)) and the transseptal needle is connected to be visualized (C) (anteroposterior views).

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  Figure 4. Ventricular tachycardia catheter ablation in a patient with tetralogy of Fallot with transcatheter pulmonary valve. The clinical ventricular tachycardia (cycle length 301 ms, 198 bpm) was easily inducible. Very-high density mapping (Rhythmia system, Boston Scientific, USA) revealed that circuit rotated around the pulmonary valve with the critical isthmus identified between the right ventricle to pulmonary artery conduit and the ventricular septal defect patch (A). A linear ablation by irrigated radiofrequency (50 W) slowed and then terminated the arrhythmia. Despite complementary applications including with retrograde aortic approach, a complete bidirectional block was not achieved as the superior part of the isthmus was covered by the transcatheter pulmonary valve (B). Reproduced with permission from Combes et al. [60].

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  Figure 5. Critical isthmus between ventricular septal defect patch and pulmonary artery in a patient with repaired tetralogy of Fallot. Voltage maps in anteroposterior (left Panel) and posteroanterior (right Panel) views. Healthy tissue is depicted in purple, scar tissue in red. The isthmus n°3 (curved arrow), between the ventricular septal defect patch and the pulmonary artery, is the critical isthmus most commonly involved in ventricular tachycardias in patients with tetralogy of Fallot. Fragmented potential with slow electrical conduction velocity (<0.5 m/s) are associated with an increased risk of ventricular arrhythmias.