It is most classically used for paroxysmal supraventricular tachycardia. It is a lifelong disease for which radical cure can be achieved using transcatheter radiofrequency ablation. For idiopathic ventricular tachycardia, i.e., ventricular tachycardia without clear organic heart disease (e.g., no cardiomyopathy, infarction, etc.), transcatheter radiofrequency ablation can also be used to obtain excellent results. Another major group of diseases that can be treated with transcatheter ablation, and one that is more prevalent, is atrial fibrillation. This is a disease that predisposes the elderly, with the average age of the disease being in the seventies. The prevalence of atrial fibrillation is about 1% in the general population, but reaches 5% in people over 60 years of age and may reach 10% in people over 80 years of age, the older the age, the higher the prevalence. One of the main dangers of atrial fibrillation is the tendency to have recurrent panic attacks, and the most serious side effect is the susceptibility to stroke. Once AF is present, the risk of stroke increases five or six times, and the prognosis for AF-related stroke is very poor, with a 30-day mortality rate of 25% and a high rate of disability. In addition, AF predisposes to heart failure, and the prognosis is poor once the two are combined. However, the effectiveness of pharmacological treatment of atrial fibrillation is limited, and the most successful aspect of pharmacological treatment is the prevention of thromboembolic events. If medications are tried to prevent the occurrence of AF, the efficacy is very poor and only improves the patient’s symptoms, not the prognosis. This is treating the symptoms but not the root cause. Therefore, in recent years, transcatheter radiofrequency ablation has become increasingly important in the treatment of atrial fibrillation. Catheter ablation can also be used as first-line treatment for patients with paroxysmal AF who prefer catheter radiofrequency ablation to antiarrhythmic drug therapy. The third major group that can be treated with radiofrequency ablation is recurrent atrial tachycardia and atrial flutter. Atrial tachycardia is a localized “excitation point” in the atria where there is an abnormally fast electrical discharge, or a small folding motion in the atria, which can be cured by ablation after accurate labeling. Atrial flutter is caused by the presence of a large loop in the atrium, and the current keeps turning around in the loop. Transcatheter radiofrequency ablation can block the loop and thus cure atrial flutter. The fourth major category is ventricular tachycardia. The most common clinical category is outflow tract ventricular tachycardia. The outflow tract is the structure where the ventricle transitions to the pulmonary artery or aorta, and ventricular tachycardia originating there is called outflow tract ventricular tachycardia. Ablation is indicated for right ventricular outflow tract or left ventricular outflow tract ventricular tachycardia in the absence of organic heart disease and in the event of recurrent episodes. Catheter ablation of idiopathic ventricular tachycardia in the left ventricular septum is also more effective. However, transcatheter radiofrequency ablation is far from the first-line treatment for ventricular tachycardia in combination with organic heart disease. The presence of organic heart disease and the progressive basis of ventricular tachycardia, coupled with thick ventricular muscle and well-developed endocardial surface trabeculae, make successful ablation more difficult. The chances of complete freedom from recurrence after ablation of ventricular tachycardia in organic heart disease are low, and the hemodynamic instability of ventricular tachycardia in the event of recurrence may put the patient at risk. Therefore, for hemodynamically unstable ventricular tachycardia, an intracorporeal defibrillator (ICD) should be placed to ensure timely recognition and termination of hemodynamically unstable ventricular tachycardia and ventricular fibrillation. In patients with ICDs and combined drug therapy, catheter ablation may be considered to reduce the incidence of ventricular tachycardia if it continues to recur. Catheter ablation may be attempted only if the ventricular tachycardia of organic heart disease is hemodynamically stable and treated with medication first, and if the ventricular tachycardia remains recurrent after medication. Fifth, the application of transcatheter radiofrequency ablation in atrial premature and ventricular premature beats is also being explored, especially in the last 10 years, radiofrequency ablation for the treatment of frequent ventricular premature beats has been affirmed by more clinical studies. If the patient has obvious symptoms, frequent ventricular premature beats, and is not well controlled by medication, radiofrequency ablation can be used regardless of the presence of organic heart disease. However, how frequent are premature ventricular contractions and what is the indication for transcatheter ablation? This definition is not yet clear. It is generally believed that more than 10% or 20% of ventricular premature beats, over time, can induce heart failure or exacerbate the deterioration of the patient’s cardiac function. Therefore, whether ventricular premature beats can be ablated depends firstly on whether the premature beats exceed 10% or 20% of the patient’s total heart rate, secondly on whether there are symptoms and the severity of the symptoms, and thirdly on whether the medication is effective. If the symptoms are obvious and the premature beats are more than 10%, radiofrequency ablation can be done. Finally, recent studies suggest that radiofrequency ablation can be performed in patients with rare types of tachyarrhythmias, such as polymorphic ventricular tachycardia or ventricular fibrillation. Some idiopathic ventricular fibrillation is caused by premature ventricular contractions, and if the occurrence of premature contractions can be removed, then episodes of ventricular fibrillation can also be reduced or disappear. Another clinical advance is that in patients with Brugada syndrome, right outflow tract epicardial and/or endocardial ablation can reduce or prevent the occurrence of polymorphic ventricular tachycardia and ventricular fibrillation. In these two groups of patients, ICD therapy should be combined with radiofrequency ablation because polymorphic ventricular tachycardia and ventricular fibrillation are life-threatening diseases that are prone to sudden cardiac death if not treated promptly.