Macro-reentrant atrial tachycardia after tricuspid or mitral valve surgery: is there difference in electrophysiological characteristics and effectiveness of catheter ablation?

Abstract

Background: Macro-reentrant atrial tachycardias (MATs) are a common complication after cardiac valve surgery. The MAT types and the effectiveness of MAT ablation might differ after different valve surgery. Data comparing the electrophysiological characteristics and the ablation results of MAT post-tricuspid or mitral valve surgery are limited.

Methods: Forty-eight patients (29 males, age 56.1 ± 13.3 years) with MAT after valve surgery were assigned to tricuspid valve (TV) group (n = 18) and mitral valve (MV) group (n = 30). MATs were mapped and ablated guided by a three-dimensional navigation system. The one-year clinical effectiveness was compared in two groups.

Results: Nineteen MATs were documented in TV group, including 16 cavo-tricuspid isthmus (CTI)-dependent AFL and 3 other MATs at right atrial (RA) free wall, RA septum and left atrial (LA) roof. Thirty-nine MATs were identified in MV group, including15 CTI-dependent AFL, 8 RA free wall scar-related, 2 RA septum scar-related, 8 peri-mitral flutter, 3 LA roof-dependent, 2 LA anterior scar-related, and 1 right pulmonary vein-related MAT. Compared with TV group, MV group had significantly lower prevalence of CTI-dependent AFL (38.5% vs. 84.2%), higher prevalence of left atrial MAT (35.9 vs.5.3%) and higher proportion of patients with left atrial MAT (40 vs. 5.6%), P = 0.02, 0.01 and 0.01, respectively. The acute success rate of MAT ablation (100 vs. 93.3%) and the one-year freedom from atrial tachy-arrhythmias (72.2 vs. 76.5%) was comparable in TV and MV group. No predictor for recurrence was identified.

Conclusion: Although the types of MATs differed significantly in patients with prior TV or MV surgery, the acute and mid-term effectiveness of MAT ablation was comparable in two groups.

Trial registration: This study was registered as a part of EARLY-MYO-AF clinical trial at the website ClinicalTrials. gov (NCT04512222).

Keywords: Atrial flutter; Catheter ablation; Macro-reentrant atrial tachycardia; Mitral valve surgery; Tricuspid valve surgery.

Conflict of interest statement

The authors declare no competing interests.

© 2021. The Author(s).

Figures

Fig. 1

Right atrial MAT ablation. In A the flutter wave of counterclockwise CTI-dependent AFL was negative in inferior limb leads (II, III and aVF), positive in precordial lead V1, and progressively became shallow negative from precordial lead V2 to V6. In B the flutter wave of clockwise CTI-dependent AFL was positive in inferior limb leads, negative in precordial lead V1, and progressively became positive in precordial lead V2 to V6. In C counterclockwise AFL was terminated by CTI linear ablation after tricuspid valve bio-prosthesis implantation. Of note, two pouches were found in proximity to the tricuspid annulus (TA) and at the mid-portion of the CTI area (white arrows). Extensive and prolonged RF energy delivery was needed to interrupt AFL and achieve CTI block. The dotted circle represented the tricuspid annulus (TA). In D right atriotomy-related macro-reentry was identified to around the scar line (gray dots line), entrainment pacing at either side of the scar line produced a matched PPI. The critical isthmus was found between the inferior border of the scar and the inferior vena cava, where short linear RF ablation terminated the tachycardia and rendered it non-inducible. Of note, the mid-diastolic, low-voltage and fractionated bipolar potentials were recorded at the critical isthmus (red arrows). In E the ATa-free survival probability was compared in MV group (solid line) and TV group (dotted line), P = 0.70 by Log-Rank test. RAO right anterior oblique view, LAO left anterior obliqueview, PA posterior-anterior view, ATa atrial tachyarrhythmia, PPI post-pacing interval, LA the left atrium, CS coronary sinus

Fig. 2

“Figure-of-eight” right atrial MAT ablation after mitral valve prosthesis replacement. A–J showed the activation sequence of the “figure-of-eight” macro-reentry using a common isthmus, which was localized in a low voltage area, bounded by bilateral lines of block K at the postero-lateral wall of the RA. The white solid lines represented lines of block defined by the system algorithm. White arrows indicated the activation direction from the earliest to the latest area. In L, M the MAT was terminated by a short linear ablation across the common isthmus (LL and PA view). Note the small diastolic potentials at the site of MAT termination. In N a prophylactic short line was added to prevent other possible macro-reentries. Abbreviations referred to Fig. 1