Late Atrial Arrhythmias as a Complication After Valvular Heart Surgery: Is There A Place for Prevention?

Abstract

Atrial arrhythmias, mostly atrial fibrillation (AF), are the most frequent complication after cardiac surgery. The incidence of postoperative AF (pAF) is 11–40% after coronary artery bypass grafting (CABG) [1–10] and over 50% after valve surgery [11, 12]. Technical advances in surgery and anesthesia and changing methods of myocardial protection have not decreased the incidence of postoperative atrial tachyarrhythmias. While the consequences of this arrhythmia are generally not life threatening (pAF), it can result in stroke, ventricular arrhythmia, pneumonia, and hemodynamic deterioration, especially in patients with depressed cardiac function. In addition, increased length and cost of hospital stay are observed. The underlying mechanism of recurrent AF in patients who are not undergoing surgery appears to be multiple, simultaneously propagating reentrant electrical impulses, or wavefronts, that circulate inside the atria. Less is known about the cause of pAF, for which other arrhythmogenic factors exist. Many factors have been tested as independent variables predictive of pAF, from systemic hypertension to postoperative bleeding, atrial manipulation, myocardial protection, cross-clamping time, excessive production of catecholamines, and respiratory or renal parameters [4, 7, 13, 14], but most have proved to be poorly correlated with the onset of pAF.