European Journal of Cardio-Thoracic Surgery, Vol 10, 490-497, Copyright © 1996 by European Association for Cardio-thoracic Surgery
Surgery for atrial fibrillation
M Vigano, A Graffigna, L Ressia, G Minzioni, F Pagani, M Aiello and F Gazzoli
Institute of Cardiac Surgery, University of Pavia, I.R.C.C.S. Policlinico S. Matteo, Italy.
OBJECTIVE: The mechanisms of atrial fibrillation arc multiple reentry
circuits spinning around the atrial surface, and these baffle any attempt
to direct surgical interruption. The purpose of this article is to report
the surgical experience in the treatment of isolated and concomitant atrial
fibrillation at the Cardiac Surgical Institute of the University of Pavia.
METHODS: In cases of atrial fibrillation secondary to mitral/valve disease,
surgical isolation of the left atrium at the time of mitral valve surgery
can prevent atrial fibrillation from involving the right atrium, which can
exert its diastolic pump function on the right ventricle. Left atrial
isolation was performed on 205 patients at the time of mitral valve
surgery. Atrial partitioning ("maze operation") creates straight and blind
atrial alleys so that non-recentry circuits can take place. Five patients
underwent this procedure. In eight-cases of atrial fibrillation secondary
to atrial septal defect, the adult patients with atrial septal defect and
chronic or paroxysmal atrial fibrillation underwent surgical isolation of
the right atrium associated which surgical correction of the defect, in
order to let sinus rhythm govern the left atrium and the ventricles. "Lone"
atrial fibrillation occurs in hearts with no detectable organic disease.
Bi-atrial isolation with creation of an atrial septal internodal "corridor"
was performed on 14 patients. RESULTS: In cases of atrial fibrillation
secondary to mitral valve disease, left atrial isolation was performed on
205 patients at the time of mitral valve surgery with an overall sinus
rhythm recovery of 44%. In the same period, sinus rhythm was recovered and
persisted in only 19% of 252 patients who underwent mitral valve
replacement along (P < 0.001). Sinus rhythm was less likely to recover
in patients with right atriomegaly requiring tricuspid valve annuloplasty:
59% vs 84% (P < 0.001). Restoration of the right atrial function raised
the cardiac index from 2.25 +/- 0.55 1/min per m2 during atrial
fibrillation to 2.54 +/- 0.58 1/min per m2, with a mean percentage increase
in cardiac index of 13.5% (P < 0.00018). Atrial partitioning ("maze
operation") was performed on five patients with an immediate sinus rhythm
recovery of 100%, but with two patients requiring pacemaker implant. Seven
out of eight patients (87.5%), with atrial fibrillation secondary to atrial
septal defect, who underwent surgical isolation of the right atrium at the
time of surgery were free from atrial fibrillation and without medications.
2-52 months after operation. Thirteen of 14 patients with "lone" atrial
fibrillation who underwent corridor procedure remained in sinus rhythm with
a sinus rhythm recovery rate of 92%. CONCLUSIONS: Different surgical
options can be chosen for different cases of atrial fibrillation, according
to the underlying cardiac disease.
