A sudden extraordinarily fast heartbeat may be associated with paroxysmal tachyarrhythmias, such as paroxysmal atrial fibrillation, paroxysmal supraventricular tachycardia, and paroxysmal ventricular tachycardia. Suddenly rapid heartbeat may be paroxysmal atrial fibrillation, some patients have idiopathic atrial fibrillation, there may also be heart valve disease or hyperthyroidism, changes in the structure of the heart, increased levels of thyroid hormones may be contributing factors. A sudden increase in heart rate may also be due to paroxysmal supraventricular tachycardia, in which the patient has an abnormal bypass tract in the heart, and cardiac conduction through the abnormal bypass tract may trigger an episode of supraventricular tachycardia. Paroxysmal ventricular tachycardia can also occur in patients with a hereditary family history or a history of acute myocardial infarction, which can lead to episodes of ventricular tachycardia. The sudden acceleration of the heart, to improve the timely examination of the electrocardiogram, to clarify the specific causes of the disease, under the guidance of the physician can be treated.