Why do things like supraventricular tachycardia, for example, recur after radiofrequency ablation? Overall, supraventricular tachycardia is curable, and for most patients a successful ablation is all that is needed. However, in a few cases, supraventricular tachycardia can recur. This is because the heart muscle is alive. The abnormal pathway that triggers the arrhythmia is like a branch on a large tree; if it is broken off, in most cases it dies, but in very rare cases the branch survives, and that can cause a recurrence of tachycardia. There are intraoperative indicators to determine whether the electrical activity of the abnormal pathway has been successfully blocked, and usually there is a re-evaluation after 30 minutes of observation, and even then there are still very few cases where the electrical conduction of the abnormal pathway may be restored postoperatively. Intraoperatively, after the electrical activity of the abnormal pathway has been successfully blocked, continued ablation of the abnormal pathway can reduce the postoperative recurrence rate, but excessive ablation also increases the risk of myocardial perforation, so the benefits and risks should be weighed. Why is the success rate of radiofrequency ablation of atrial fibrillation low? Most patients with atrial fibrillation tachycardia have only one abnormal bypass connection between the atria and ventricles, and the risk of recurrence after successful ablation is 1-2%. The most important lesion in atrial fibrillation is located in the pulmonary veins, which have many electrical connections to the left atrium, and the chance of recurrence is elevated. Another difference from supraventricular tachycardia is that atrial fibrillation is a progressive disease, with a low incidence of atrial fibrillation at a young age and a predisposition to atrial fibrillation at an older age if combined with diseases such as hypertension. After successful ablation of atrial fibrillation, the main cause of early recurrence is the restoration of the electrical connection between the pulmonary veins and the atria, while late recurrence is due to the development of new ectopic foci of excitation that induce atrial fibrillation. Atrial fibrillation is somewhat like coronary heart disease, which may be a problem with multiple vessels one after another; this vessel is cleared by putting a stent in it, but another vessel may still be blocked. What happens when an arrhythmia recurs? Different arrhythmias are defined as recurrence after ablation. More specifically, recurrence of atrial tachycardia, atrial flutter and atrial fibrillation within 3 months after atrial fibrillation ablation should be observed until 3 months after the procedure if the episodes are infrequent. A recurrence of atrial arrhythmias of more than 30 seconds duration, regardless of atrial tachycardia, atrial flutter, or atrial fibrillation, 3 months after AF ablation is defined as a recurrence. Symptoms of paroxysmal supraventricular tachycardia recurrence are sudden onset and abrupt cessation of panic or palpitations accompanied by a sudden acceleration of the heart rate lasting from several minutes to several hours each time, and the ECG recording at the time of the attack provides a clear diagnosis. Atrial flutter, atrial tachycardia and ventricular tachycardia recurrence are also manifested by panic, and the diagnosis can be made clearly by ECG recording during the attack. Depending on the rapidity of the heart rate and the presence and extent of underlying heart disease during an episode of tachycardia, the patient may experience profuse sweating, dizziness, blackness, or even syncope, as well as aggravation of the existing heart disease, such as dyspnea and chest pain. Can I have radiofrequency ablation again after an arrhythmia recurrence? Most of the arrhythmias can be ablated by radiofrequency again after recurrence, such as supraventricular tachycardia, atrial tachycardia, atrial flutter, ventricular tachycardia, etc. The tachycardia will recur after one recurrence, so it is still advisable to do radiofrequency ablation again. However, for ventricular tachycardia with combined organic heart disease, the purpose of catheter ablation is mostly to reduce recurrent episodes of ventricular tachycardia that cannot be controlled by drugs, so if the ventricular tachycardia episodes are significantly reduced compared with those before the procedure, the purpose of ablation therapy is achieved. In the case of arrhythmias alone, radiofrequency ablation can be done again if the symptoms are severe after recurrence. In a few patients, a comprehensive judgment is needed. For example, in some patients with atrial fibrillation, there is only one episode of atrial fibrillation 3 months after surgery, and then there is no recurrence for a year, then the patient can continue to be observed. In addition, a few patients with recurrence may have a combination of other diseases, such as tumor or stroke in elderly patients. At this point, it is important to determine whether the arrhythmia is still a major problem for the patient, how long the survival period is after treatment, and other issues. Is the difficulty and treatment process of radiofrequency ablation different for different types of arrhythmias? Not really. We have just introduced several means of marker measurement and ablation catheters. The more complex the arrhythmia, the more complex the marking tools and special ablation catheters are needed, such as 3D marking systems and cold saline perfusion or pressure ablation catheters. The simplest is the common type of supraventricular tachycardia, which has a very high success rate using a common ablation catheter and 2-D labeling methods. In experienced treatment centers, the success rate of a single ablation procedure is over 99%. In cases such as persistent atrial fibrillation or ventricular tachycardia with combined organic heart disease, the procedure is more difficult to perform and often needs to be completed with a three-dimensional marker, and the use of a cold saline infusion catheter can further improve the success rate.