Atrioventricular Node Conduction Block

Chest | Cardiology | Atrioventricular Node Conduction Block (Disease)


Description

Atrioventricular (AV) block is a condition that happens when atrial depolarizations fail to reach the ventricles or is conducted with a delay. There are known three degrees of AV block.

Causes and Risk factors

The causes of pathological AV block are varied and include ischaemia, infarction, fibrosis or drugs. Certain AV blocks can also be found as normal variants, such as in athletes or children, and are benign.

Diagnosis and Treatment

Systemic diseases, such as ankylosing spondylitis and Reiter syndrome, may affect the AV nodal conducting tissue. Surgical procedures like aortic valve replacement and congenital defect repair may cause AV block. The incidence of AV block increases with age. First-degree heart block generally requires no treatment. When the cause are medication, the dosage must be reevaluate.

Type I second-degree heart block is generally treated by addressing any underlying conditions. A permanent pacemaker is generally not necessary unless the condition worsens, but temporary pacing and/or medication may be required if the heartbeat is too slow.

Type II second-degree heart block often produces noticeable symptoms and carries a significant risk of potentially life-threatening complications. Medications and implantation of a permanent pacemaker are recommend.

Third-degree heart block patients almost always require an artificial pacemaker to better regulate the electrical activity of the heart. ...