Nueva técnica para prevenir las macrorreentradas auriculares tras cirugía cardiaca en pacientes con cardiopatías congénitas

Laburpena

1. Objective: To present and test a simple method that may prevent one of the commonest long-term complications of surgery for congenital heart disease: atrial reentrant tachycardia. This arrhythmia may occur many years (even decades) after the operation. It is most commonly explained as a late consequence of right atriotomy, which is an inherent component of many operations for congenital heart disease. Right atriotomy results in a long scar on the right atrial myocardium. This scar, as any scar, is a barrier to electrical conduction, and macro-reentrant circuits may form around it causing reentrant tachycardia. This mechanism is the target of our proposed preventive antiarrhythmic method, i.e. to prevent the formation of reentrant circuits around right atriotomy scars. 2. Methods: The proposed method is implemented after termination of cardiopulmonary bypass and tying the venous purse-strings. It consists of constructing a full-thickness suture line on the intact right atrial wall from the IVC (a natural conduction barrier) to the atriotomy incision. This suture line is made to cross the venous cannulation sites if these are on the atrial myocardium (rather than being directly on the venae cavae). Thus, the IVC, atriotomy and cannulation sites are connected to each other in series by a full-thickness suture line on the atrial wall. If this suture line becomes a conduction barrier, it would prevent reentrant circuits around right atrial scars. This was tested in 13 adults by electroanatomical mapping. All 13 had previously undergone right atriotomy for ASD closure: 8 of them with the addition of the proposed preventive suture line (treatment group) and 5 without (control group). 3. Results: In all 13 cases, the atriotomy scar was identified as a barrier to electrical conduction with electrophysiological evidence of fibrosis (scarring). In all 8 patients with the proposed suture line, this had also become a scar and a complete conduction barrier. In the 5 patients without this suture line, there was free electrical conduction between the IVC and atriotomy scar. 4. Conclusions: The proposed suture line becomes a scar and conduction barrier. Therefore, it would prevent reentrant circuits around atrial scars and their consequent arrhythmias.