A prolonged PR interval is a clinical diagnosis on the electrocardiogram that refers to a slowing of the electrical impulses of the heart during conduction, or even a block in conduction, and once this occurs, it should be combined with other ancillary tests, such as cardiac ultrasound, coronary CTA, nuclear myocardiography, or even coronary angiography, to clarify what is causing the prolonged PR interval. If the patient has other diseases, like myocardial ischemia or heart valve disease, they can also cause a prolonged PR interval. Therefore, once this condition occurs, the cause of the prolonged PR interval should be clarified through various ancillary tests, and timely symptomatic treatment should be given in order to restore the patient to a healthy state more quickly.