heart and blood vessel disorders
Atrial Fibrillation and Atrial Flutter
Causes of Atrial Fibrillation and Atrial Flutter
Atrial fibrillation or atrial flutter may occur even when there is no other heart disorder. More often, these arrhythmias are caused by such conditions as High Blood Pressure None Overview of Coronary Artery Disease (CAD) None Overview of Heart Valve Disorders affecting the mitral and/or tricuspid valves Alcohol Use None An Hyperthyroidism (hyperthyroidism) A Overview of Heart Defects None Heart valve disorders and high blood pressure cause the atria to enlarge, making atrial fibrillation or atrial flutter more likely. The main complications include the following: Blood clots in the atria Rapid heart rate, causing decreased heart output In atrial fibrillation or atrial flutter, the atria do not empty completely into the ventricles with each beat. Over time, some blood inside the atria may stagnate, and blood clots may form. Pieces of the clot may break off, often shortly after atrial fibrillation converts back to normal rhythm—whether spontaneously or because of treatment. These pieces of clot may pass into the left ventricle, travel through the bloodstream (becoming emboli), and block a smaller artery. If pieces of a clot block an artery in the brain, a Overview of Stroke results. Rarely, a stroke is the first sign of atrial fibrillation or atrial flutter. When atrial fibrillation or atrial flutter causes the heart to beat too rapidly, the ventricles do not have enough time to fill completely with blood. Because they do not fill completely, the amount of blood pumped by the heart decreases. This decrease may cause the blood pressure to fall, and Heart Failure (HF) may occur. Because blood can pool inside the heart's atria and form clots, which can then travel from the heart to the brain, atrial fibrillation is a strong risk factor for stroke. 