Spectrum of arrhythmogenic substrate post minimally invasive maze surgery in patients with recurrent

• Published in: Pacing and clinical electrophysiology 2021-06, Vol.44 (6), p.1054-1061
• Main Authors: Larsen, Timothy R., Koneru, Jayanthi N., Padala, Santosh K., Kasirajan, Vigneshwar, Ellenbogen, Kenneth A.
• Format: Article
• Language: English
• Subjects: Ablation; Aged; Arrhythmia; Atrial Fibrillation - surgery; atrial fibrillation ablation; Atrial Flutter - surgery; Cardiac arrhythmia; Catheter Ablation - methods; Electrophysiologic Techniques, Cardiac; Electrophysiology; Female; Fibrillation; Humans; Male; Middle Aged; minimally invasive surgical maze; Minimally Invasive Surgical Procedures; posterior wall isolation; Pulmonary Veins - surgery; Recurrence; recurrent arrhythmias; Surgery; surgical ablation; Tachycardia
• ISSN: 0147-8389; 1540-8159
• DOI: 10.1111/pace.14242

Background Advancements in minimally invasive surgical ablation (MISA) have focused on improving pulmonary vein isolation. Additional ablation targets have been developed (such as posterior wall isolation). The mid‐ and long‐term effects of current techniques (including electrophysiologic findings and recurrent arrhythmia mechanisms) have not previously been reported. Methods Twenty eight patients with recurrent atrial arrhythmias after bipolar clamp ablation of the pulmonary vein antrum, ganglionated plexi, posterior wall isolation (roof and floor lines to create a posterior box), and ligament of Marshall ligation/cauterization and left atrial appendage clipping underwent follow up electrophysiology study including left atrial mapping an average of 2.3 years postoperatively. Results Atrial fibrillation was the most common recurrent arrhythmia (n = 18) followed by micro‐reentrant atrial tachycardia (n = 5), macro‐reentry left atrial flutter (n = 3), and typical cavo‐tricuspid isthmus atrial flutter (n = 2). Eighty six of 112 (77%) PVs mapped were electrically isolated, 16 (57%) patients had all four pulmonary veins (PVs) isolated. The posterior wall (PW) was completely isolated in only four (14%) patients, seven (25%) patients had normal PW voltage, while 17 (61%) patients had abnormal delayed or fractionated electrograms in the posterior wall (incomplete isolation). Abnormal PW electrograms were more frequently found in patients with complex recurrent left atrial arrhythmia (micro‐reentry or left atrial macro‐reentry flutter). Conclusion With current surgical techniques PV isolation has improved, but PW isolation remains challenging. Incomplete PW isolation may produce arrhythmogenic substrate.