The fast and irregular flow of the blood reduces the efficiency of the heart . The incidence of atrial fibrillation after cardiac surgery is 18.8 % of 49 264 patients , from the database between 2001 until 2012 in The Virginia Cardiac Surgery Quality Initiative . It is the cause of one in five strokes , and it reduces the quality of life . When it occurs after heart surgery , the risk of symptomatic hypotension , thromboembolism and heart failure is increased .
The European Society of Cardiology published guidelines for the control of the ventricular rate . There are five types of clinical symptoms for atrial fibrillation ( AF ), based on the time length : newly diagnosed , paroxysmal ( 2 days ) , persistent ( 7 days ) , long - standing persistent and permanent ( 1 year ) . The AF is associated with alterations of the extracellular matrix ( amyloid deposition , inflammatory behaviour , interstitial fibrosis ) , of the myocyte ( apoptosis , hypertrophy , intracellular accumulation of substrate ) , at microvascular level , and with remodelling of the endocardium .
Prolonged hospitalization may be required as the postoperative AF develops in the first three days after heart surgery . The systemic inflammation , triggered by the extracorporeal blood circulation during surgery , and the reactive oxygen species ( ROS ) in the atria are the causes for the postoperative AF .
Monoamine oxidase ( MAO ) is an enzyme on the outer membrane of the mithocondrion in the cardiac cell . It is a major factor in the balance between the reduction and the oxidation reactions in the atrial myocardium . The emission of mitochondrial H2O2 was measured in samples of myocardial tissue from 244 patients for cardiopulmonary bypass . Figure 1 outlines the incidence quartiles of postoperative AF in the cohort based on the enzymatic activity .
Figure 1 . The activity of the MAO and the incidence of the postoperative AF . Copyright ( 2014 ) Journal of The American Heart Association .
There are gaps in the clinical evidence that need to be understood :
- the increase in the electrocardiogram ( ECG ) screening
- the benefit of multimodal therapy
- effective biomarkers for antithrombotic therapy
- increase the cohort with undiagnosed AF
- the atrioventricular node ablation
References :
Anderson E . J . , Efird J . T . , Davies S . W . , O ‘ Neal W . T . , Darden T . M . , Thayne K . A . , Katunga L . A . , Kindell L . C . , Ferguson B . , Anderson C . A . , Chitwood W . R . , Koutlas T . C . , Williams J . M . , Rodriguez E . , Kypson A . P . ( 2014 ) “ Monoamine oxidase is a major determinant of redox balance in human atrial myocardium and is associated with postoperative atrial fibrillation ” , Journal of the American Heart Association , 3 .
Camm A . J . , Kirchhof P . , Lip G . Y . H . , Schotten U . , Savelieva I . , Ernst S . , Van Gelder I . C. , Al – Attar N . , Hindricks G . , Prendergast B . , Heidbuchel H . , Alfieri O . , Angelini A . , Atar D . , Colonna P . , De Caterina R . , De Sutter J . , Goette A . , Gorenek B . , Heldal M . , Hohloser S . H . , Kolh P . , Le Heuzey J . - Y . , Ponikowski P . , Rutten F . H . ( 2010 ) “ Guidelines for the management of atrial fibrillation ” , European Heart Journal , 31 , 2369 - 2429 .
LaPar D . J . , Speir A . M . , Crosby I . K . , Fonner E . , Brown M . , Rich J . B . , Quader M . , Kern J . A . , Kron I . L . , Ailawadi G . ( 2014 ) “ Postoperative atrial fibrillation significantly increases mortality , hospital readmission , and hospital costs ” , The Annals of Thoracic Surgery , 98 ( 2 ) , 527 – 533 .
