First degree AV block is an abnormality in the conduction of electrical excitation between the atria and ventricles, which prevents the heart from contracting and pumping blood properly, and the ECG shows a prolonged PR interval of more than 0.20s. Atrioventricular block is also known as delayed atrioventricular conduction and is generally classified as first degree, second degree or third degree, with three different degrees of severity. First-degree AV block is the mildest form of block and is often asymptomatic, with only abnormalities on the electrocardiogram.
First degree AV block is often caused by vagal excitation and has a mild effect on the body, sometimes in healthy people. Some patients affected by flu, fever, myocarditis, ischaemia, etc. may also develop this pathology. If the pathology is caused by a disease, intervention for the primary disease is sufficient.