The clinical manifestations of thyroid heart disease include symptoms and signs. First, looking at the symptoms, patients often present with tachycardia, palpitation sensation, and arrhythmias, mainly atrial arrhythmias, including paroxysmal and persistent atrial fibrillation. A small number of patients may have atrioventricular block, and in severe atrioventricular block, As syndrome may occur. Patients often feel mild but heavy pain in the precordial region and may present with right heart failure. Second, look at the physical signs. There is often sinus tachycardia, the heart rate remains significantly higher than normal during sleep, the precordial pulsation is enhanced with elevated beats, the first heart sound is hyperactive, a systolic murmur is present in the apical region, and a few may have a mild diastolic murmur. The second heart sound of the pulmonary valve is enhanced and a third heart sound may be present. Occasionally, a systolic scraping sound, similar to a pericardial rub, may be heard between the 2nd and 3rd ribs at the left sternal border. Signs similar to aortic valve insufficiency are also present, and cardiac enlargement may be present.