Clinical impact of atrial electric stabilization in patients with chronic atrial fibrillation undergoing cardiac surgery
© BioMed Central Ltd 2005
Published: 9 June 2005
Atrial fibrillation (AF) is frequent in patients undergoing cardiac surgery (CS). Despite the high prevalence of chronic AF in patients with valvular heart disease, few studies have assessed the clinical evolution of these patients when undergoing CS.
To assess the clinical outcome of patients with chronic AF undergoing CS who evolved with electric atrial stabilization in the immediate postoperative period (IPO).
A prospective and observational study of patients undergoing CS with extracorporeal circulation (ECC) divided into two groups: Group 1 (G1), patients who maintained AF; and Group 2 (G2), patients who reverted to AF in the IPO. The following preoperative (PRE) parameters were assessed: left ventricular (LV) and right ventricular function; functional class; left atrium (LA) size (>5 mm); LV hypertrophy (>12 mm); presence of SAH, DM, COPD, CAD; use of AA drugs; and LBBB. The following perioperative (PER) parameters were assessed: atrial thrombus; plication of the atrial auricle; time of ECC and of anoxia; and chemical and/or electric CV. The following variables influenced the clinical outcome: mechanical ventilation time (MVT), ICU length of stay (ICULOS), hospital length of stay (HLOS), and maintenance of AF. The statistical analysis involved the following tests: Student t test, Fisher exact test, and Mann–Whitney test.
G1 comprised 21 patients (14 women, 66.6%) with a mean age of 52.6 years, and G2 comprised 33 patients (15 women, 45%) with a mean age of 49.8 years (P = not significant). No statistical difference was observed in regard to the PRE and PER variables, except for the LA size >5 mm (G1 85.7%, G2 45%, P = 0.0031), MVT, ICULOS, and HLOS. Of G1 patients, only one (4.7%) reverted his rhythm to sinus rhythm, while 24 patients (72.7%) in G2 maintained their sinus rhythm until ICU discharge (P = 0.000022).
In this sample, LA size was the major predictor of maintenance of AF, which did not determine greater morbidity. Once AF is reverted, however, one should not restrain efforts to maintain atrial electric stability.