Atrial Fibrillation (AFib)

Atrial Fibrillation (AFib) is a common heart rhythm disorder that affects the heart's upper chambers, called the atria. In this condition, the atria beat irregularly and often very fast, which can cause poor blood flow to the rest of the body. This irregular heartbeat can lead to symptoms like palpitations, fatigue, and sometimes shortness of breath. Because the heart does not pump efficiently, blood can pool and form clots, increasing the risk of a stroke. The condition involves the cardiovascular system and can affect overall health by reducing the heart's ability to supply oxygen-rich blood to organs and tissues. It is more common in older adults and those with other heart conditions.

Atrial Fibrillation (AFib) is defined as a supraventricular tachyarrhythmia characterized by disorganized atrial electrical activity leading to ineffective atrial contraction. The core pathology involves multiple reentrant wavelets causing rapid, irregular atrial depolarizations, typically with an atrial rate of 350-600 beats per minute. This results in an irregularly irregular ventricular response due to variable conduction through the atrioventricular node. Common causes include hypertension, ischemic heart disease, valvular heart disease, and hyperthyroidism. The major clinical significance of AFib lies in its association with thromboembolism, particularly ischemic stroke, and its contribution to heart failure due to loss of atrial kick and rapid ventricular rates. Diagnosis and management focus on rate or rhythm control and stroke prevention.