Risk factors, morbidity, and mortality associated with atrial fibrillation in the postoperative period of cardiac surgery.
OBJECTIVE
To determine the incidence of atrial fibrillation in the postoperative period of cardiac surgery, its impact on morbidity, mortality, and hospital stay, and to analyze the risk factors in the pre, trans, and postoperative periods.


METHODS
Contemporary cohort study with 158 adult patients undergoing cardiac surgery, of whom those with atrial fibrillation in the preoperative period were excluded. The patients were assessed with continuous cardiac monitoring and daily electrocardiograms. Any episode of irregular rhythm with the presence of f waves of variable morphology and amplitude was considered atrial fibrillation.


RESULTS
The general incidence of atrial fibrillation was 28.5%, being 21.6% for revascularized patients and 44.3% for those undergoing valvular repair. Factors independently associated with atrial fibrillation were left heart failure in the preoperative period (p=0.05; RC=2.2), total fluid balance (p=0.01; RC=1.0), duration of surgery (p=0.03; RC=1.01) [and other associated factors, age > 70 years, aortic valvular disease, psychomotor agitation, length of installation of the drains, pulmonary congestion and respiratory insufficiency in the postoperative period]. The use of beta-blockers (p=0.01; RC=0.3) was a protective factor. Atrial fibrillation in the postoperative period was associated with an increase in the length of hospital stay (16.9+/-12.3 days versus 9.2+/-4.0 days, p<0.001) and a greater incidence of stroke or postoperative death (p=0.02).


CONCLUSIONS
The incidence of atrial fibrillation in the postoperative period of cardiac surgery was high and caused a significant increase in morbidity, mortality, and the length of hospital stay. Among the independent risk factors, excessive fluid balance is significant. The use of beta-blockers was identified as a protective factor.
Instituto de Cardiologia do Rio Grande do Sul, Fundação Univeresitária de Cardiologia, Porto Alegre, RS, Brazil. gglima.pesquisa@cardiologia.org.br
Rogério Gomes da
RG
Silva
Gustavo Glotz de
GG
Lima
Andréia
A
Laranjeira
Altamiro Reis da
AR
Costa
Edemar
E
Pereira
Rubem
R
Rodrigues
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000401:mortality; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000401:mortality