cardiovascular disorders
Atrial Fibrillation
Complications of atrial fibrillation
The absent atrial contractions predispose to thrombus formation; annual risk of cerebrovascular embolic events is about 7%. Risk of Overview of Stroke is higher in older patients and in patients with a rheumatic valvular disorder, mechanical heart valve, hyperthyroidism, hypertension, diabetes, left ventricular systolic dysfunction, or previous thromboembolic events. Systemic emboli can also cause malfunction or necrosis of other organs (eg, heart, kidneys, gastrointestinal tract, eyes) or a limb. Atrial fibrillation also may impair cardiac output; loss of atrial contraction can lower cardiac output at normal heart rate by about 10%. Such a decrease is usually well tolerated except when the ventricular rate becomes too fast (eg, > 140 beats/minute), or when patients have borderline or low cardiac output to begin with. In such cases, Heart Failure (HF) may develop. 