Left ventricular dysfunction in atrial fibrillation: restoration of sinus rhythm by the Cox-maze procedure significantly improves systolic function and functional status.
BACKGROUND
Atrial flutter or fibrillation with rapid, uncontrolled ventricular response may lead to left ventricular dysfunction, and conversion to sinus rhythm with control of heart rate can improve left ventricular ejection fraction. Little is known about the effects of the Cox-maze procedure on this form of tachycardia-induced cardiomyopathy.


METHODS
Four hundred forty-three patients underwent the Cox-maze procedure from 1993 to 2002. Ninety-nine had atrial flutter or fibrillation without associated valvular or congenital heart disease, and 37 (37%) had decreased left ventricular function (ejection fraction < 0.35 in 11 [severe], ejection fraction 0.36 to 0.45 in 8 [moderate], and ejection fraction 0.46 to 0.55 in 18 [mild]). Ages of these 37 patients (34 male) ranged from 35 to 74 years (median, 55 years).


RESULTS
Atrial flutter or fibrillation was present for 3 months to 19 years (median, 48 months) preoperatively, and 24 patients (65%) exhibited symptoms of heart failure. Preoperative ejection fraction ranged from 0.25 to 0.55 (median, 0.45). At last follow-up (median, 63 months), the Cox-maze procedure eliminated atrial flutter or fibrillation in all but 1 patient, and the greatest improvement was observed in patients with severe preoperative impairment (0.31 to 0.53; p = 0.01, preoperative versus follow-up), and patients with preoperative chronic atrial flutter or fibrillation (0.43 to 0.55; p < 0.05 preoperative versus follow-up). This improvement was observed immediately postoperatively and was sustained at last follow-up. Further, improvement in left ventricular function correlated with enhancement of functional status.


CONCLUSIONS
In some patients, atrial flutter or fibrillation may be the cause rather than the consequence of left ventricular dysfunction. Importantly, systolic function and functional status can be significantly improved with the restoration of sinus rhythm by the Cox-maze procedure.
Stulak
John M
JM
Division of Cardiovascular Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Dearani
Joseph A
JA
Daly
Richard C
RC
Zehr
Kenton J
KJ
Sundt
Thoralf M
TM
Schaff
Hartzell V
HV
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D006348:Cardiac Surgical Procedures / Q000379:methods*; D001026:Coronary Artery Bypass; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D014859:Warfarin / Q000627:therapeutic use
D014859:Warfarin