Distribution of thromboembolism in valvular versus non-valvular atrial fibrillation

The most feared consequence of atrial fibrillation (AF) is thromboembolism, either to the brain causing stroke or to the non-cerebral circulation. Valvular atrial fibrillation (VAF) and non-valvular atrial fibrillation (NVAF) differ not only by morphological substrate of arrhythmia but also by the rate of thromboembolic complications, predisposing factors and destination of embolism. In the setting of VAF, there is a higher risk of thromboembolism and a higher prevalence of thrombus location within the body of the left atrium compared to NVAF. VAF is also associated with a proportionally higher propensity for non-cerebral thromboemboli than in NVAF. The distribution of non-cerebral thromboemboli appears to be similar in VAF and NVAF; however, more research needs to be done in this area, particularly with regard to VAF.