| Atrial Fibrillation (AF or AFib) Atrial fibrillation occurs when the four chambers of the heart beat in an irregular rhythm. The two upper chambers of the heart are the atria and the two lower chambers are the ventricles. The sequence and timing of the contractions of these four chambers is usually tightly controlled by electrical impulses originating from an area located in the upper part of the right atrium known as the sinoatrial (SA) node. Electrical impulses from the SA node signal the two atria to contract and empty the blood within the atria into the ventricles. The electrical impulse then reaches and stimulates another area known as the atrioventricular (AV) node located in between the atria and the ventricles. The AV node relays the signal down to the ventricles and causes the ventricles to contract. The right ventricle functions to pump blood into the lung tissues for oxygenation and the left ventricle functions to supply oxygenated blood to the rest of the body. During AF, many electrical impulses are sent out from the SA node simultaneously to stimulate the AV node. As a result of these rapid irregular impulses, the heartbeat becomes irregular and disorganized. The irregular heartbeat also causes the blood to become relatively stagnant in the left atrium and increases the risk of blood clot formation which may lead to stroke. The symptoms of AF include shortness of breath, heart palpitations, dizziness, and chest pain. AF can lead to heart failure and stroke. AF can be treated with antiarrhythmic drug. Another option is heart rate control medication, such as beta-blockers and calcium channel blockers. Antithrombotic drugs (blood thinner) are usually prescribed at the same time to reduce the risk of blood clot formation. |
Atrial Fibrillation
Cardiovascularweb
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