Atrioventricular Block (AV block) is a condition where the electrical signals between the heart's upper chambers (atria) and lower chambers (ventricles) are delayed or blocked. This disruption can lead to a slower heart rate and may cause symptoms like fatigue, dizziness, or fainting. There are three degrees of AV block, with the first degree being mild and often asymptomatic, while the third degree is more severe and can be life-threatening. Treatment options vary depending on the severity and may include medications or the implantation of a pacemaker to help regulate the heart's rhythm.