Treatment of atrial tachycardia arising after superior transseptal approach mitral valve surgery: Insights from ultra‐high‐density mapping to prevent atrioventricular block

Abstract

Mitral valve surgery employing a superior transseptal approach (STA) is associated with arrhythmogenicity and intra-atrial conduction delay, despite being optimal for visualization of the surgical field. It is sometimes difficult to treat atrial tachycardias (AT) that arise after STA. To investigate AT circuits that arise after STA in detail in order to identify the optimal ablation line, using ultra high-resolution mapping (UHRM). We retrospectively analyzed 12 AT from 10 patients (median age 70 years, 9 males) who had undergone STA surgery. The tachycardias were mapped using the Rhythmia mapping system (Boston Scientific, Natick, Massachusetts). The 12 STA-related AT (STA-AT) circuits were classifiable as follows according to location of the optimal ablation line: (1) peri-septal incision STA-AT (n = 3), (2) cavotricuspid isthmus dependent STA-AT (n = 7) and (3) biatrial tachycardia (n = 2). Radiofrequency (RF) application terminated 11 of the 12 STA-AT. We found that difference in STA-AT circuit type was due to characteristics of the septal incision line made for STA. UHRM was important in identifying optimal ablation sites that did not create additional conduction disturbances in the right atrium. ATs after STA involve complex arrhythmia circuits due to multiple and long incision lines in the right atrium. Accurate understanding of the arrhythmia circuit and sinus conduction in the right atrium after STA is recommended for treating post-surgical tachycardia in a minimally invasive manner. This article is protected by copyright. All rights reserved.