Category: At-At

An entry chamber. On both sides of the heart, the atrium is the chamber that leads to the ventricle.

The electrical relay station between the upper and lower chambers of the heart. Abbreviated AV node. Electrical signals from the atria must pass through the AV node to reach the ventricles. The AV node, which controls the heart rate, is one of the major elements in the cardiac conduction system. The AV node serves as an electrical relay station, slowing…

Pertaining to the atria (the upper chambers of the heart) and the ventricles (the lower chambers of the heart). The AV node is an electrical relay station between the atria and the ventricles. Electrical signals from the atria must pass through the AV node to reach the ventricles. The AV node is a major element in the cardiac…

A genetic syndrome characterized by the combination of heart disease and malformations of the upper limb. The heart defect is usually an atrial septal defect (ASD) and, less often, a ventricular septal defect (VSD), although other cardiovascular malformations have been reported. The upper limb malformations most often affect the forearm and thumb. The thumb may be absent or it may be…

The wall between the right and left atria of the heart.

A hole in the septum, the wall, between the atria, the upper chambers of the heart. Commonly called an ASD. ASDs constitute a major class of heart formation abnormalities present at birth (congenital cardiac malformations). Normally, when clots in veins break off, they travel first to the right side of the heart and, then to the lungs where…

Well-organized but overly rapid contractions of the atrium of the heart (usually at a rate of 250-350 contractions per minute). Flutter refers to a rapid vibration or pulsation. The difference between flutter and fibrillation is that flutter is well organized while fibrillation is not. Atrial flutter is a serious and potentially unstable rhythm of the heart.

An abnormal and irregular heart rhythm in which electrical signals are generated chaotically throughout the upper chambers (atria) of the heart. Many people with atrial fibrillation have no symptoms. Among those who do, the most common symptom is an uncomfortable awareness of the rapid and irregular heartbeat (palpitations). Atrial fibrillation can promote the formation of blood clots that travel from the heart to…

Atrial fibrillation.

Abnormal heart rhythm due to electrical disturbances in the atria (the upper chambers of the heart) or the AV node “relay station”, leading to fast heart beats. Examples of atrial arrhythmias includes atrial fibrillation, atrial flutter, and paroxysmal atrial tachycardia (PAT).