Prevalence of intra-atrial reentrant tachycardia following mitral valve surgery: Relationship to surgical approach.

BACKGROUND AND AIM

Mitral valve (MV) surgeries create electrophysiological substrates that give rise to postoperative arrhythmias. MV surgical procedures have been associated with macro- and microreentrant arrhythmogenic circuits, as well as circuits involving the atrial roof. It is not well understood why such arrhythmias develop; therefore, the aim of this study was to describe clinical and procedure characteristics associated with atrial arrhythmias in patients with prior MV surgery.

METHODS

This retrospective chart review evaluated patients who had prior MV surgery and ablation procedures for atrial tachycardia between 2014 and 2018 (n = 20). Patients were classified into those exhibiting typical atrial flutter or another atrial tachyarrhythmia.

RESULTS

Within the 20 patient cases reviewed, 30 arrhythmias were documented. Two-thirds of arrhythmias were typical atrial flutter; the percent incidence of arrhythmias originating in the right atrial (RA) roof, around the right atriotomy scar, in the left atrium, and at the crista terminalis was 20%, 3%, 7%, and 7%, respectively. Nearly every case of RA roof flutter (n = 5/6) and most arrhythmias (n = 20/30) occurred in patients who had a transseptal approach during MV surgery. Voltage maps did not show clear differences in scarring between groups.

CONCLUSION

Results from this study suggest that an arrhythmogenic substrate for RA roof tachycardias is generated by transseptal approaches for MV surgery. This substrate is not clearly related to a surgical scar. These data suggest that other approaches should be considered for MV surgeries. Additionally, more research is needed to determine the mechanism for this nonscar-related arrhythmia substrate.