title: Association of heart rhythm with exercise capacity after operation for chronic mitral regurgitation.
abstract: BACKGROUND
  Although atrial fibrillation (AF) and decreased exercise capacity are common in chronic mitral regurgitation patients, the relationship between rhythm status and exercise capacity after corrective surgery is largely unknown.
  
  
  METHODS
  Seventy-one patients undergoing repair or replacement of mitral valve for chronic severe mitral regurgitation were examined with preoperative and 6 months' postoperative cardiopulmonary exercise test and two-dimensional echocardiography. Patients were divided into three groups according to preoperative versus postoperative rhythm (sinus/sinus, SS [n=42]; AF/sinus, AS [n=17]; AF/AF, AA group [n=12]).
  
  
  RESULTS
  Preoperative maximal oxygen consumption was lower and ventilatory efficiency was higher in the AS and AA groups compared with the SS group. However, maximal oxygen consumption improved only in the AS group at 6 months' postoperative cardiopulmonary exercise test (24.0±6.9 versus 24.6±6.1 mL·kg(-1)·min(-1) in the SS group, 19.3±5.9 versus 23.2±6.4 mL·kg(-1)·min(-1) in the AS group, 19.8±5.4 versus 18.8±5.1 mL·kg(-1)·min(-1) in the AA group; p=0.016 for maximal oxygen consumption by analysis of covariance) as well as ventilatory efficiency. Echocardiography verified more significant reduction of left atrial volume in the SS and AS groups than in the AA group (172.2±68.0 versus 96.7±31.0 mL in the SS group, 247.5±77.8 versus 129.2±25.7 mL in the AS group, 316.7±210.0 versus 192.0±95.0 mL in the AA group; p=0.001 for left atrial volume by analysis of covariance) as well as pulmonary artery systolic pressure. When analyzed for significant predictors of postoperative maximal oxygen consumption, being in the AS group but not the SS group was a significant positive predictor when compared with the AA group (β=5.475; p=0.006).
  
  
  CONCLUSIONS
  Successful sinus conversion of AF, preferably by maze operation, in patients undergoing surgical correction of chronic severe mitral regurgitation confers improved exercise capacity. Reduction of left atrial volume and pulmonary artery pressure may contribute to this improvement.
authors.affiliation: Cardiovascular Center, Seoul National University Hospital, Seoul, Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Seung-Pyo
authors.initials: SP
authors.lastname: Lee
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Joo Myung
authors.initials: JM
authors.lastname: Lee
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Hwang
authors.forename: Hyung-Kwan
authors.initials: HK
authors.lastname: Kim
authors.forename: Kyung-Hwan
authors.initials: KH
authors.lastname: Kim
authors.forename: Ki-Bong
authors.initials: KB
authors.lastname: Kim
authors.forename: Dae-Won
authors.initials: DW
authors.lastname: Sohn
authors.forename: Hyuk
authors.initials: H
authors.lastname: Ahn
authors.forename: Byung-Hee
authors.initials: BH
authors.lastname: Oh
authors.forename: Young-Bae
authors.initials: YB
authors.lastname: Park
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D019560:Echocardiography, Three-Dimensional; D017548:Echocardiography, Transesophageal; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D058386:Mitral Valve Annuloplasty; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000601:surgery*; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011474:Prosthesis Design