Impact of left atrial volume reduction concomitant with atrial fibrillation surgery on left atrial geometry and mechanical function

• Published in: The Journal of thoracic and cardiovascular surgery Vol. 135; no. 6; pp. 1297 - 1305
• Main Authors: Marui, Akira, MD, PhD, Saji, Yoshiaki, MD, Nishina, Takeshi, MD, PhD, Tadamura, Eiji, MD, PhD, Kanao, Shotaro, MD, Shimamoto, Takeshi, MD, Sasahashi, Nozomu, MD, Ikeda, Tadashi, MD, PhD, Komeda, Masashi, MD, PhD
• Format: Journal Article
• Language: English
• Published: United States Mosby, Inc 01-06-2008; AATS/WTSA
• Subjects: Aged; Atrial Fibrillation - complications; Atrial Fibrillation - diagnosis; Atrial Fibrillation - surgery; Cardiac Surgical Procedures - methods; Cardiac Surgical Procedures - mortality; Cardiothoracic Surgery; Catheter Ablation - methods; Cohort Studies; Combined Modality Therapy; Electrocardiography; Female; Follow-Up Studies; Heart Atria - pathology; Heart Atria - surgery; Heart Valve Prosthesis Implantation - methods; Heart Valve Prosthesis Implantation - mortality; Humans; Hypertrophy - complications; Hypertrophy - pathology; Hypertrophy - surgery; Magnetic Resonance Imaging; Male; Middle Aged; Mitral Valve Insufficiency - complications; Mitral Valve Insufficiency - diagnostic imaging; Mitral Valve Insufficiency - surgery; Multivariate Analysis; Myocardial Contraction - physiology; Regression Analysis; Retrospective Studies; Stroke Volume; Survival Analysis; Treatment Outcome; Ultrasonography; magnetic resonance imaging; 24; 35; CF; AF; MRI; reservoir function; left atrial; LV; atrial fibrillation; conduit function; RF; LA; booster pump function; BPF; left ventricular
• ISSN: 0022-5223; 1097-685X
• DOI: 10.1016/j.jtcvs.2008.02.026

Objective Left atrial geometry and mechanical functions exert a profound effect on left ventricular filling and overall cardiovascular performance. We sought to investigate the perioperative factors that influence left atrial geometry and mechanical functions after the Maze procedure in patients with refractory atrial fibrillation and left atrial enlargement. Methods Seventy-four patients with atrial fibrillation and left atrial enlargement (diameter ≥ 60 mm) underwent the Maze procedure in association with mitral valve surgery. The maximum left atrial volume and left atrial mechanical functions (booster pump, reservoir, and conduit function [%]) were calculated from the left atrial volume-cardiac cycle curves obtained by magnetic resonance imaging. A stepwise multiple regression analysis was performed to determine the independent variables that influenced the postoperative left atrial geometry and function. Results The multivariate analysis showed that left atrial reduction surgery concomitant with the Maze procedure and the postoperative maintenance of sinus rhythm were predominant independent variables for postoperative left atrial geometry and mechanical functions. Among the 58 patients who recovered sinus rhythm, the postoperative left atrial geometry and function were compared between patients with (VR group) and without (control group) left atrial volume reduction. At a mean follow-up period of 13.8 months, sinus rhythm recovery rate was better (85% vs 68%, P < .05) in the VR group and maximum left atrial volume was less (116 ± 25 mL vs 287 ± 73 mL, P < .001) than in the control group. The maximum left atrial volume reduced with time only in the VR group (reverse remodeling). Postoperative booster pump and reservoir function in the VR group were better than in the control group (25% ± 6% vs 11% ± 4% and 34% ± 7% vs 16% ± 4%, respectively, P < .001), whereas the conduit function in the VR group was lower than in the control group, indicating that the improvement of the booster pump and reservoir function compensated for the conduit function to left ventricular filling. Conclusion Left atrial reduction concomitant with the Maze procedure helped restore both contraction (booster pump) and compliance (reservoir) of the left atrium and facilitated left atrial reverse remolding. Left atrial volume reduction and postoperative maintenance of sinus rhythm may be desirable in patients with refractory AF and left atrial enlargement.