When children come to the hospital with their parents, they often complain of rapid heartbeat, irregular heartbeat, palpitations, and panic. Are these diseases: are they serious? Do they need to be treated? What is the best treatment? Some of them are normal, such as sinus arrhythmia, while others need active treatment, otherwise they may lead to cardiac insufficiency or even life-threatening. In fact, arrhythmias are very common in adolescents, such as atrioventricular node folding tachycardia, preexcitation syndrome, idiopathic ventricular tachycardia, ventricular tachycardia after congenital heart disease repair, premature ventricular beats, congenital AV block, long QT syndrome, Brugada syndrome, etc. Some episodes are frequent and cause significant symptoms, even leading to arrhythmogenic heart disease. Advances in pharmacological and interventional treatment of arrhythmias. In recent years, clinical and basic research on antiarrhythmic drugs has made great progress, further improving the status of antiarrhythmic drug therapy; radiofrequency catheter ablation, the only treatment technique that can cure tachyarrhythmias today, has achieved good results in pediatrics, and the indications have been expanded accordingly. With the rapid development of pediatric cardiac surgery, the effectiveness of congenital heart disease repair surgery has been greatly improved, and the recognition and proper treatment of postoperative congenital heart disease, especially late postoperative arrhythmias, has led to improved postoperative productivity. Currently, the pediatric cardiology department of the National Cardiovascular Center – Fu Wai Cardiovascular Hospital performs radiofrequency surgical treatment of pediatric arrhythmias involving: I. Atrial arrhythmias: (1) Paroxysmal supraventricular tachycardia (1) AVNRT (atrioventricular nodal foldback tachycardia): about 16-20% of pediatric supraventricular tachycardia. Due to the presence of dual pathways in the AV node, abnormal conduction of excitation can form in the heart, triggering tachycardia. The success of radiofrequency ablation surgical treatment is over 95%. (2) W-P-W preexcitation syndrome: It is the most common pediatric supraventricular tachycardia accounting for more than 50% of the cases. It is due to the abnormal development of the fetal heart and the presence of a bypass with conduction function across the atrioventricular valve annulus. The heart rate can be as high as 200-300 beats per minute during tachycardia attacks, and in severe cases, continued attacks can lead to cardiac insufficiency or even sudden death. The success rate of radiofrequency ablation surgery for this type of disease is greater than 96%. (3), AT atrial tachycardia: about 10% of supraventricular tachycardia, milder cases are short-onset episodes, severe cases can last for several years, which can lead to heart enlargement and cardiac insufficiency. The success rate of radiofrequency ablation for pediatric atrial tachycardia is 70-90%, but the success rate is related to the location of the origin of atrial tachycardia and there is a certain recurrence rate. (b) Atrial flutter Pediatric atrial flutter can develop from fetal period to all age groups. According to the clinical electrocardiographic characteristics, atrial flutter is divided into typical atrial flutter and atypical atrial flutter, and according to the characteristics of electrophysiological examination, atrial flutter can be divided into type I atrial flutter and type II atrial flutter. Atrial flutter caused by scarring after surgery for congenital heart disease and atrial flutter caused by intracardiac electrophysiological stimulation also belong to type I atrial flutter. The results of typical atrial flutter are good with isthmus ablation by radiofrequency ablation. Ventricular arrhythmias: (a) Ventricular premature beats Ventricular premature beats are very common arrhythmias in childhood. Although these premature beats are benign, they need to restrict children’s physical activities due to their long-term presence, which seriously affects the quality of life of the children. Long-term frequent ventricular premature beats may lead to cardiac enlargement and cardiac insufficiency in children, which can also be treated by radiofrequency ablation. The success rate of radiofrequency ablation is more than 90% for children with frequent monogenic ventricular premature beats originating from the right ventricular outflow tract and without organic heart disease. (2) Paroxysmal ventricular tachycardia is usually combined with serious organic heart disease, such as cardiomyopathy, congenital heart disease, especially in postoperative children, and in severe cases, heart failure, cardiogenic shock, syncope or even sudden death can occur. The prognosis depends mainly on the severity and clinical manifestations of the underlying heart disease. Catheter radiofrequency ablation can treat the life-threatening effects of ventricular arrhythmias. (iii) Idiopathic ventricular tachycardia accounts for about 10-15% of paroxysmal tachycardia. Organic heart disease must be excluded from the diagnosis. Clinically, there are two categories (1) idiopathic right ventricular tachycardia originating in the right ventricular outflow tract; (2) idiopathic tachycardia originating in the left ventricular septum. The former is easily resolved and has a better prognosis than the latter. Those with severe symptoms, ineffective drug therapy, and cardiomyopathy due to tachycardia should be considered for treatment with radiofrequency ablation surgery with 90% or more success. The rapid development of pediatric cardiac surgery has saved the lives of children with severe cardiovascular malformations, yet those who survive the procedure can become at high risk for severe arrhythmias. Due to surgical trauma, scar tissue and electrophysiological abnormalities caused by implantation of artificial foreign bodies, 75% of survivors develop sinus node dysfunction and or tachyarrhythmias; for example, 3-7% of survivors of the common tetralogy of Fallot die suddenly due to severe ventricular arrhythmias in the later stages. The widespread availability of transcatheter radiofrequency ablation procedures and the expansion of the indications have brought hope and benefit to these children.