| Left atrial endocardial damage |
| Activation of coagulation system within the left atrium |
| High levels of biochemical markers |
| Fibrinopeptide A Thrombin-antithrombin III complex Von Willebrand factor antigen [62] [63] |
| Paraneoplastic (due to altered intravascular coagulation related to carcinoma breast [64] or lung [65] ) |
| Rhythm changes (atrial fibrillation or atrial flutter) |