Most cases of first-degree AV block do not get worse without treatment. This is because in many cases it is caused by a physiologic cause. If it is caused by pathologic reasons, with the progression of the primary disease, there may be second or even third-degree AV block, which will lead to progression and aggravation of the disease. Normal people can develop first degree AV block, which can be seen in healthy adults, children and athletes. Most of them do not have clinical symptoms and do not require special treatment, and the condition usually does not progress. However, some cases may be caused by pathologic diseases, such as digitalis toxicity, hyperkalemia, coronary artery disease, myocarditis and so on. These conditions need to be treated for the primary disease. If the primary disease persists, it may further lead to second or even third degree AV block, resulting in progression and aggravation of the condition. If ECG abnormalities are found, prompt medical attention is recommended to avoid delays.