AV Block occurs when the signal from the heart's upper to lower chambers does not get transmitted  or is impaired. When this occurs it is considered an impairment - blood vessels and blood flow are not blocked.

First degreee AV block occurs when the electrical impulse that travels through the AV node travels at slower speeds than normal. If it takes the electrical impulse longer than 0.2 seconds to transmit, it is considered first degree AV block. If you have first degree AV block it does not mean that your heart is damaged. This depends of your heart rate and heart rhythm and whether they are normal or abnormal.

Under normal circumstances, no treatment is generally required for first degree AV block.