Why is Postoperative Atrial Fibrillation Difficult to Prevent and Treat: Potential Roles of Unrecognized Magnesium Deficiency and Release of Ceramide and Platelet-Activating Factor

Abstract

Post-operative atrial fibrillation (POAF) is the most prevalent complication after cardiac or lung surgery, occurring in about 20-50 percent of these patients [1-5]. This event often leads to increased morbidity, thromboembolisms, strokes and long-term mortality resulting in recurring hospitalizations and increased costs. Often the cause(s) of POAF is not known. Age, previous history of atrial fibrillation (AF), hypertension, diabetes, myocardial infarction, valvular heart disease, left ventricular hypertrophy, obesity, excessive drinking of alcohol and excessive smoking present great risk factors for development of POAF [15]. According to a number of reports, the incidence of cerebral infarction and heart failure can increase two-four fold after PAOF [1-5]. Added to this, are a number of growing autopsy studies which demonstrate that many of the PAOF patients, who have died, have considerable atherosclerotic plaques on the walls of the coronary vessels leading to the idea that inflammatory events probably play an important role in the PAOF syndrome [5]. POAF is usually managed by digoxin, calcium channel blockers, betablockers, quinidine, amiodarone, direct current cardioversion, catheter ablation inside the heart, or appropriate rate control techniques to restore rhythm to normal [1-5]. Although digoxin is often utilized, it can present direct risks for POAF patients and has been associated with increased hospitalizations and mortalities [6, 7]. Such data has raised serious concerns about use of digoxin, one of our oldest and most controversial drugs . Ever since 1935 [8], digoxin and cardiac glycosides have been known to deplete the human body and heart of magnesium (Mg) [for review, see [9]]. Several studies have suggested that use of intravenous magnesium sulfate may be better than either betablockers, calcium channel blockers, or amiodarone [1, 5, 10-12]. This concept is currently under investigation by several groups in the USA and Europe. Abstract