Pathophysiological Insights into Atrial Fibrillation Following Cardiac Surgery: Implications for Current Pharmaceutical Design

Abstract

Atrial fibrillation (AF) following cardiac surgery is a common complication, which increases incidence of other complications, hospital and healthcare costs. The reported rate of the occurrence of postoperative AF varies with different studies, depending on population profile, type of surgery, arrhythmia definition and detection methods, design of study. Nonetheless, the precise mechanisms of AF related to cardiac surgery are poorly understood. A diverse variety of reasons have been proposed for the pathogenesis of this common cardiac arrhythmia. The aim of this review article is to provide an overview of pathophysiological processes that lead to the development of AF post-cardiac surgery. These processes are closely inter-related but the most important ones that have bearing on drug design include the RAAS, ion channels, connexins, fibrosis and extracellular matrix turnover, inflammation and oxidative stress. The autonomic nervous system and structural remodeling all influence all these pathophysiological processes, which should not be viewed in isolation. Understanding such processes would have major implications for the approach to current pharmaceutical design, to improve our approach to drug management strategies.

Age as a Risk Factor for Stroke in Atrial Fibrillation Patients

“…We appreciate that perioperative AF is also an important predictor of post-operative stroke, thromboembolism, and mortality, as highlighted in various reviews (7)(8)(9), but the focus of this paper will be thromboprophylaxis in the nonsurgical setting, and more on the outpatient nonacute clinical setting.…”

Effect of bronchodilator treatment on the incidence of postoperative atrial fibrillation after cardiac surgery

“…2,6,[23][24][25] Understanding the conditions that are related and more likely to precipitate this arrhythmia are an important step toward managing POAF in cardiac surgery patients. 10,24,26 Patients with advanced age and combined operative procedures developed more POAF.…”

Evaluation of an Evidence-Based Practice Implementation

“…1 Surgical manipulation and cross-clamping can increase tissue stress with a resultant inflammatory response. 6 Electrolyte imbalance and elevated circulating catecholamines affect the stability of the conduction system. The Figure represents factors associated with POAF.…”

“…3,4 The occurrence of POAF is likely generated in the presence of an electrophysiological or structural change that triggers either a focal source or dispersion of atrial refractoriness resulting in multiple reentry waves. 6,7 Premature atrial contractions triggered near or at the pulmonary veins, left atrial junction, inferior vena cava, or coronary sinus can initiate atrial fibrillation. 7 Impaired contraction, reduced refractory time, and repeated triggering may also contribute to atrial remodeling, maintaining atrial fibrillation once it occurs.…”