What is cardiac radiofrequency ablation? Cardiac radiofrequency ablation is an interventional technique to block the abnormal conduction bundle and origin of rapid arrhythmias by delivering an electrode catheter through a vein or arterial vessel into a specific part of the heart cavity and releasing radiofrequency current to cause local endocardial and subendocardial myocardial coagulative necrosis. Radiofrequency current introduced through the catheter into the cardiac cavity can cause damage in the range of 1-3 mm and is not harmful to the organism. Radiofrequency ablation has become the most effective method for the treatment of paroxysmal tachycardia. The basic equipment includes X-ray machine, radiofrequency ablation instrument and intracardiac electrophysiological examination instrument. Radiofrequency ablation indications 1, atrioventricular foldback tachycardia: there is a congenital “bypass” between atria and ventricles, the catheter radiofrequency will “cut off” the bypass, the tachycardia or preexcitation wave will no longer exist. 2.Atrioventricular node foldback tachycardia: Atrioventricular node forms a “double pathway”, and the current runs fast in the foldback loop formed by the two pathways under suitable conditions, causing tachycardia; catheter radiofrequency ablates the slow pathway and retains only the fast pathway, and the tachycardia will no longer have conditions for attack. 3, atrial flutter: atrial flutter is the presence of large loops in the atria, the current in the loop non-stop circle, atrial beats 250-350 times / min, the ventricle is generally at 150 times / min; catheter radiofrequency can destroy the loop, resulting in two-way current block, thereby eradicating atrial flutter. 4, atrial tachycardia: atrial tachycardia is a local “excitation point” in the left atrium or right atrium with abnormally fast issuing current or small folding movement in the atrium; electrophysiological examination is marked to detect the ectopic “excitation point” or folding loop, and ablation is performed to get radical treatment. 5.Ventricular premature contraction: mainly used for monogenic frequent ventricular premature with obvious clinical symptoms; often caused by ventricular “excitation foci”; ablation of ectopic excitation foci can be detected and ventricular premature can disappear. 6, ventricular tachycardia: including idiopathic, bundle branch folding and scarring ventricular tachycardia. Idiopathic ventricular tachycardia is common in people with normal heart structure and function and no evidence of organic heart disease, but frequent episodes of tachycardia can cause tachycardia cardiomyopathy; it occurs when an “excitation focus” in the right or left ventricular outflow tract and the left ventricular septum sends a rapid current, resulting in tachycardia. Ventricular tachycardia can be cured by locating the “foci of excitation” through a catheter and delivering radiofrequency current for ablation. Bundle-branch folding ventricular tachycardia and scarring ventricular tachycardia are most commonly seen in patients with organic heart disease such as dilated heart disease, coronary artery disease and post-surgical precordial disease, where patients may experience syncope and convulsions and often require emergency resuscitation. Bundle branch regression ventricular tachycardia is a regression loop between the left and right conduction bundle branches of the heart and the left and right ventricles, and the catheter electrode finds and distributes radiofrequency current to block the loop; scar ventricular tachycardia is a regression loop generated by the surviving cardiomyocytes between the cardiac fibrous scar tissue, and the tachycardia is also cured by distributing radiofrequency current to block the loop. Catheter radiofrequency ablation can cure ventricular tachycardia but not heart disease; when ablation is unsuccessful or when ventricular tachycardia attacks are life-threatening, a cardiac buried defibrillator needs to be implanted to prevent sudden death. 7, atrial fibrillation: atrial fibrillation is the most common persistent arrhythmia, research has found that atrial fibrillation is triggered by the “myocardial sleeve” on the large vein connected to the atria to issue rapid electrical impulses, in addition to the persistence of atrial fibrillation and atrial remodeling is also related. The use of catheter electrodes to ablate at the mouth of the circumferential pulmonary vein, forming an “electrical isolation” between the large vein and the atrium, or coupled with some linear ablation in the atrium, can achieve radical treatment of atrial fibrillation. Pediatric radiofrequency ablation has the characteristics of fine blood vessels and small heart, so it is difficult and risky to perform radiofrequency ablation, so it needs to be chosen carefully. For children with tachyarrhythmia under 3 years old, try to take drug treatment first, and consider radiofrequency ablation surgery for children over 3 years old. For arrhythmias such as premature beats, drugs cannot shorten the course of the disease, but only relieve the symptoms, and drug therapy should be highly alert to its toxic side effects; only when tachycardia affects the quality of life and physical development of the child should anti-arrhythmic drug therapy be actively used, and radiofrequency ablation therapy should be adopted in suitable cases. IV. Procedure of electrophysiological examination and radiofrequency ablation Electrophysiological examination and radiofrequency ablation are performed in a procedure room with special equipment. The catheterization room staff usually includes electrophysiologists, assistants, nurses and technicians. The patient lies on an X-ray bed and the medical staff will connect various monitoring devices to the patient’s body and cover your body with a sterile sheet while the medical staff puts on sterile gowns and gloves. The skin of the catheter insertion site (groin, arm, shoulder or neck) is first disinfected and local anesthesia is administered with local anesthetic; then the venous/arterial vessels are punctured with a puncture needle and the electrophysiology catheter is inserted into the heart chambers through the vessels; the electrode catheter used for cardiac electrophysiology is a long, bendable catheter that transmits electrical signals into and out of the heart. The electrode catheter records the electrical activity in different parts of the heart and issues weak electrical stimulation to stimulate the heart in order to induce arrhythmias and clarify the diagnosis of tachycardia; then the doctor finds the exact site of abnormal electrical activity in the heart through the catheter and then sends radiofrequency current ablation treatment through the ablation instrument to cure the tachycardia. V. Electrophysiological examination and radiofrequency ablation process patient feeling The whole process patient is generally in the awake state, sometimes the doctor will use sedatives to relieve the patient’s tension, the patient will be monitored throughout; electrophysiological examination generally does not cause pain, the patient will not feel when the catheter travels through the blood vessels and heart chambers; examination doctor may stimulate the heart with a weak electric current, the patient will not feel these electrical impulses, often induce the Tachycardia, feeling the same as in previous episodes, inform the doctor can; these operations have very little risk and are relatively safe. Six, radiofrequency ablation precautions 1, electrophysiological examination and radiofrequency ablation generally need to be hospitalized, need routine laboratory tests. 2, dietary precautions: do not eat and drink within 6-8 hours before surgery. 3.Tell the doctor the name and dosage of the drugs used. Discontinue all antiarrhythmic drugs 3-5 days before electrophysiological examination and radiofrequency ablation, as antiarrhythmic drugs may affect the examination results. 4. Tell the doctor about the allergy to the drug. The success rate of radiofrequency ablation can reach over 98% for atrioventricular node folding tachycardia, preexcitation syndrome and other arrhythmias, and over 90% for atrial tachycardia, atrial flutter, ventricular premature, idiopathic ventricular tachycardia and other complex arrhythmias. The success rate of ablation will be further improved. Possible complications of radiofrequency ablation Vascular puncture complications include local bleeding, hematoma, infection, pneumothorax, thrombosis, embolism, etc. Catheter operation complications include aortic regurgitation, myocardial perforation, pericardial tamponade, etc. Discharge ablation complications include atrioventricular block, myocardial infarction, etc. 9.Post-radiofrequency ablation precautions After radiofrequency ablation, patients must be bed-rested according to medical advice, sandbag compression at the venous puncture for 6 hours, sandbag compression at the arterial puncture for 8-12 hours, and braking of the affected limbs, pay attention to observe whether bleeding, and give an easily digestible diet during bed-rest. Early after radiofrequency ablation, closely observe the heart rate and rhythm, report to the doctor if there is discomfort, and if necessary, electrocardiogram, cardiac ultrasound and chest X-ray; if there is a feeling of tachycardia again after the operation, but not a real attack, there is no need to be nervous and do not need special treatment, and normal activities can be resumed after 1 week after the operation; if there is a recurrence after discharge, the electrocardiogram should be recorded in the nearest place in time, and contact with the surgeon to decide the next treatment plan. Decide the next treatment plan. Anticoagulation therapy is required after radiofrequency ablation, generally requiring 1-3 months of anticoagulants, depending on the patient’s heart rhythm, age and systemic condition. Other adjuvant medications, mainly amiodarone after AF ablation, should be administered as prescribed to achieve the desired outcome.