I. What is paroxysmal supraventricular tachycardia? Paroxysmal supraventricular tachycardia is often referred to as supraventricular tachycardia, which is also a kind of tachycardia. The main manifestations are panic, anxiety, dizziness, syncope, angina pectoris, and in severe cases, heart failure and shock. Patients usually have no organic heart disease and can occur in different genders and ages. What are the characteristics of paroxysmal supraventricular tachycardia? People with this disease have the same discomfort as normal people when they do not have the disease. The electrocardiogram is abnormal in some patients and can be completely normal in others, depending on the cause of the tachycardia. The onset of the disease is without any aura and the heartbeat suddenly accelerates, the pulse is mostly above 160 beats/min, and this heartbeat also returns to normal suddenly. The duration of the attack varies from a few seconds to a few days. Most patients can stop on their own after the onset of the attack and a few patients must be medicated before the symptoms can be stopped. What to do in case of a tachycardia attack? People without heart disease can use the method of stimulating the pharynx, such as using tongue depressor or fingers to stimulate the pharynx to produce nausea and vomiting, so that some patients can stop tachycardia. Massage of the carotid sinus and compression of the eye can also be used under professional guidance. In the event of an attack, if the above methods do not work, the patient should go to the hospital and be treated with medication. Electrical cardioversion is required when severe angina pectoris hypotensive heart failure occurs. 4. What is the preexcitation syndrome? Pre-excitation syndrome is one of the causes of supraventricular tachycardia. It is an abnormal phenomenon of atrioventricular conduction in which the electrical conduction line is faulty and is transmitted down through an additional channel that excites part or all of the ventricle early, causing early excitation of part of the ventricular muscle, and pre-excitation itself does not cause symptoms. However, when combined with supraventricular paroxysmal tachycardia, there will be panic (palpitations), anxiety, dizziness, syncope and even sudden death. The diagnosis of preexcitation syndrome is mainly based on the electrocardiogram. The causes of supraventricular tachycardia include atrioventricular junctional tachycardia in addition to preexcitation, and atrial tachycardia belongs to this category. How is supraventricular tachycardia treated? If the patient has never had an episode of tachycardia, no treatment is necessary. In patients with tachycardia, in addition to emergency treatment in case of tachycardia, catheter radiofrequency ablation can cure supraventricular tachycardia. For patients with preexcited syndrome combined with supraventricular tachycardia who are unable or unwilling to undergo ablation, pharmacological treatments such as propafenone (cardioplegia), verapamil (isoptin) and amiodarone are available. Catheter radiofrequency ablation is well established, safe, effective and can cure tachycardia, and should be considered as a priority.