Introduction and objectives. The MAZE procedure was developed as a sur
gical approach to the management of patients with atrial fibrillation
refractory to medical treatment. This study seeks to identify the risk
and benefits of adding the MAZE procedure in patients with atrial fib
rillation undergoing surgery for underlying organic cardiac disorders.
Material and methods. Since november 1993, we have performed 10 inter
ventions with the MAZE procedure, for the treatment of refractory atri
al fibrillation. The indication to perform the technique,vas systemic
embolism in 5 patients, contraindication for the anticoagulant treatme
nt in two cases and no response to antiarrhythmic treatment in 5 cases
. Two patients had more than one indication. In all the cases another
surgical procedure was performed, 5 replacements of mitral valve, a mi
tral repair, one tricuspid repair and tree repairs of an atrial septal
defect. Results. Soon after surgery 9 patients were in sinus rhythm,
and one in atrial fibrillation. Four patients needed atrial pacing dur
ing the first days. One patient required a pacemaker due to symptomati
c sinus bradycardia. During the first 3 months, 4 patients had episode
s of paroxysmal atrial fibrillation and flutter. One patient died sudd
enly one month after surgery. Seven patients have completed two years
of follow-up, and are in stable sinus rhythm, in functional class I an
d free of antiarrhythmic drugs. AU of them have echocardiographic evid
ence of mechanical activity in both atria. Left atrium had been reduce
d from 5.3 +/- 0.7 cm to 4.5 +/- 0.7 cm (p < 0.05). No patient has pre
sented new embolic events. Conclusions. The MAZE procedure is a good c
hoice in selected patients with atrial fibrillation refractory to medi
cal treatment, or a precedent of systemic embolism. However, several p
roblems can complicate the patient's course.