Second-degree AV block is not usually directly inherited, but some of the primary causes of second-degree AV block can be inherited. Most cases of second-degree AV block are associated with a combination of primary causes, including certain preexisting conditions and certain cardiomyopathies, both of which have a genetic component to their cause. There are also many other factors that contribute to second-degree AV block such as medications and viral infections that are not related to heredity. Second-degree AV block is a common clinical arrhythmia caused by damage to the cardiac conduction system due to various organic heart diseases such as coronary artery disease, rheumatoid artery disease, or viral infections, as well as adverse reactions to medications, and abnormalities of electrophysiologic conduction of the heart, which cause rhythmic changes in the heart. Patients with mild symptoms usually only need regular ECG examination and clinical observation. However, patients with severe disease should pay close attention to the problem and take active measures for clinical intervention to avoid serious adverse consequences. Patients with second-degree AV block should avoid strenuous exercise and overexertion, and seek prompt medical attention if symptoms occur.