Atrial flutter after coronary artery bypass grafting: proposed mechanism as illuminated by independent predictors

The aim of this study was to evaluate the cause and treatment of atrial flutter after coronary artery bypass grafting (CABG).

Between July 1999 and July 2000, 96 CABGs were performed at the Cardiovascular Center of Aichi Prefectural Owari Hospital. We compared two groups of patients: those with atrial flutter after CABG (group A) and those without atrial flutter (group B).

We treated the atrial flutter group with medication, electrical defibrillation, and overdrive pacing. Six of these cases later required radiofrequency catheter ablation (RFCA). These were all with common-type atrial flutter, treated by RFCA for the posterior isthmus, without difficulty. The frequency of direct cannulation to the coronary sinus for retrograde cardioplegia was significantly higher in group A.

Incidence of atrial flutter after CABG was influenced by surgical damage arising from direct cannulation to the coronary sinus for retrograde cardioplegia. Preoperative viability of the myocardium (in addition to good myocardial protection during surgery) also seems to be associated with an increased likelihood of postoperative atrial flutter.