what is av block
Atrioventricular (AV) block is a type of abnormal heart rhythm, or arrhythmia. The heartâs rhythm (heartbeat) is regulated by natural electrical impulses that travel through the heart muscle.These impulses tell the heartâs chambers when to contract.trioventricular (AV) block is a type of abnormal heart rhythm, or arrhythmia. The heartâs rhythm (heartbeat) is regulated by natural electrical impulses that travel through the heart muscle.