One of the more commonly seen irregular heart rhythms at the FAA is atrial fibrillation, or AFib. Your normal electrical heart beat originates in the upper chamber in the heart known as the atrium. It starts in an area known as the sinus node and spreads from there. In atrial fibrillation the electrical impulse begins from many areas, at least 250 in a minute! Fortunately, all these impulses do not make the heart contract (or beat). The problem this irregular heart rhythm causes is that the blood in the atria cannot be adequately pumped out. The turbulence of blood as the atria are "fibrillating" also results in the formation of clots. If a clot breaks loose, it can result in a stroke. AOPA Online.
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