First-degree atrioventricular block with fast heart rate should go to the hospital, complete the relevant examinations, such as electrocardiogram, cardiac ultrasound, laboratory tests, etc., to clarify what causes, and then carry out targeted treatment, you can consider oral ivabradine to control the heart rate. Atrioventricular block of degree I refers to the prolonged conduction of excitation from the atria to the ventricles, which can be clearly diagnosed through electrocardiography. If the diagnosis is first-degree AV block, it is recommended to have further examination, such as 24-hour dynamic electrocardiogram, cardiac ultrasound, etc., to clarify whether there is any accompanying other diseases, and then carry out symptomatic treatment for the primary disease. If it is only the first degree AV block, no special treatment is needed. Common physiological causes of rapid heart rate can be seen after strenuous exercise, after drinking a lot of alcohol, emotional excitement, etc. Pathological causes can be seen in valvular disease, rheumatoid artery disease, myocarditis, etc., but also for other reasons, such as hyperthyroidism, anemia and so on. If it is clear that the heart rate is increasing, we should further improve other examinations to clarify whether it is caused by pathological reasons, and then carry out symptomatic treatment for the cause. If the cause is physiologic, it will recover on its own after the cause is removed. If the conduction block is combined with a fast heart rate, consider taking ivabradine to reduce sinus rhythm in the sinus node, which does not affect atrioventricular block. If there is any abnormality in the examination or if you feel unwell, it is recommended that you consult a doctor in time to avoid delaying your condition.