Atrial fibrillation

Atrial fibrillation, supraventricular arrhythmia in the heart a supraventricular arrhythmia. In the design of a heart seen in section, the stasis of the flow induced by the anarchic contractions of the atria led to the formation of a clot (thrombus) in the left auricle. At the top of the image a normal ECG (electrocardiogram) shows the different colors corresponding to the electrical conduction on the heart. Venous and arterial blood flow is represented in transparency. (Photo by: BSIP/Education Images/Universal Images Group via Getty Images)