Atrial fibrillation, or AF for short, is one of the most common clinical arrhythmias. In atrial fibrillation, the direction of excitation conduction in the atria is inconsistent, the frequency is fast and irregular, and the atria lose their effective contraction function. In atrial fibrillation, the frequency of atrial excitation is as high as 300-600 beats/min. Although the protection of the atrioventricular node prevents all these excitations from reaching the ventricles, the ventricular rate (heart rate) can still reach 100-160 beats/min, which is faster than the normal sinus heart rate, and the rhythm is definitely not uniform. Patients often present with a fast and irregular self-perceived heartbeat and an irregular pulse. Electrocardiogram in atrial fibrillation. Atrial fibrillation can be classified into five categories according to the timing and characteristics of the patient’s atrial fibrillation episodes: primary atrial fibrillation, paroxysmal atrial fibrillation, persistent atrial fibrillation, permanent atrial fibrillation, and long-range persistent atrial fibrillation. Paroxysmal atrial fibrillation refers to those who can convert to sinus rhythm on their own within 7 days, usually for an hour; persistent atrial fibrillation refers to those who persist for more than 7 days and require pharmacological or electrical resuscitation to convert to sinus rhythm; permanent atrial fibrillation refers to those who cannot convert to sinus rhythm, or whose physicians and patients have accepted that the persistence of atrial fibrillation does not intend to convert to sinus rhythm; when atrial fibrillation lasts for more than 1 year and conversion to sinus rhythm is considered When atrial fibrillation has persisted for more than 1 year and is being considered for conversion to sinus rhythm (e.g., when radiofrequency ablation is proposed), it is called long-standing persistent AF. What are the causes and symptoms of atrial fibrillation? Common causes of atrial fibrillation include hypertension, valvular heart disease, heart failure, hyperthyroidism, post-operative cardiac surgery, cardiomyopathy, coronary artery disease, pericarditis, congenital heart disease, and pulmonary artery embolism. Heavy alcohol consumption and smoking increase the risk of developing atrial fibrillation. Other contributing factors include: exertion, emotional stress, mental stress, caffeine intake, hypoxia, electrolyte disturbances, severe infections and the effects of certain medications. Sometimes, atrial fibrillation can also occur in individuals under 65 years of age without any underlying cardiac disease nor other common triggers of atrial fibrillation, called isolated or idiopathic atrial fibrillation, which is not uncommon in clinical practice. Previously, the most common cause of atrial fibrillation in China was rheumatic valvular heart disease (referred to as rheumatic heart disease), especially rheumatic mitral stenosis. In recent decades, with the improvement of health conditions, the incidence of rheumatic heart disease has significantly decreased, and the atrial fibrillation caused by it has also greatly decreased, and hypertensive heart disease has become the most common cause of atrial fibrillation nowadays. Some of the elderly patients with atrial fibrillation are manifesting the tachycardia phase of bradycardia-tachycardia syndrome. The symptoms of atrial fibrillation are varied and depend on the presence of organic heart disease, the basis of cardiac function, the fast or slow ventricular rate and the form of the attack. Idiopathic atrial fibrillation and ventricular rate may be asymptomatic, but on the contrary, there may be symptoms such as panic, chest tightness, shortness of breath, dizziness and fatigue, and some patients also have a combination of sweating, increased urination and other manifestations of vegetative nerve dysfunction. Patients with particularly rapid heartbeat may experience a drop in blood pressure and cardiac insufficiency, which may lead to acute pulmonary edema, angina pectoris or cardiogenic shock in severe cases. In some patients with paroxysmal atrial fibrillation, when the heartbeat automatically returns to sinus rhythm from atrial fibrillation, a slowing of the heartbeat or even temporary cardiac arrest may occur. If no heartbeat appears for 2-3 seconds, the patient may experience blackness before the eyes or even a brief loss of consciousness so that he or she faints to the ground. There are also a significant number of patients who can have no obvious conscious symptoms, yet the dangers of atrial fibrillation still exist, and many such patients are discovered by chance during a medical examination or even when they have a stroke. What are the risks of atrial fibrillation? The main risks of atrial fibrillation are stroke and heart failure. In atrial fibrillation, the mechanical contraction of the atria is lost, and blood stagnates and thrombus forms. If the thrombus is dislodged, the embolus can circulate throughout the body and cause cerebral infarction or embolism of the body circulation, which can lead to disability and death. The incidence of thromboembolic events in patients with atrial fibrillation is 5 to 17 times higher than that in normal subjects. The annual stroke rate in non-valvular atrial fibrillation patients without anticoagulation is 5.3%, and 35% of patients have had at least one stroke in their lifetime. Old age, hypertension, diabetes mellitus, coronary artery disease, and a history of chronic heart failure are all risk factors for stroke in atrial fibrillation. Therefore, anticoagulation is necessary for patients with atrial fibrillation who are at high risk for stroke. Second, loss of effective atrial systolic function and prolonged rapid heart rate in patients with AF can lead to tachycardia cardiomyopathy, which eventually leads to decreased cardiac function or even heart failure. Treatment of atrial fibrillation Medications: The goal is twofold: one is to restore and maintain sinus rhythm, which is the best outcome, and the other is to maintain a less rapid ventricular rate, which is a compromise for patients who cannot maintain a ventricular rate. Drugs to restore and maintain sinus rhythm include: cardioplegia, sotalol, amiodarone, etc. and, abroad, flecainide. Drugs to control ventricular rate include: betalactam, digoxin, diltiazem, and verapamil. Each drug has its own scope of use and adverse effects, so it is recommended to see a specialist for guidance on how to take them. Radiofrequency ablation Atrial fibrillation radiofrequency ablation is an interventional procedure that is minimally invasive, with only two puncture points in the right and left femoral veins (root of the thigh). The procedure is performed under local anesthesia and the patient is awake throughout the procedure. Most patients may have a slight burning sensation during the ablation, but it is mostly tolerable. After the procedure, patients need to lie down for 12 hours and then can get out of bed and be observed for 1 day. Who are the patients suitable for ablation surgery? Patients with atrial fibrillation without underlying heart disease, so-called isolated atrial fibrillation or idiopathic atrial fibrillation; 2. Patients with well-controlled hypertension combined with atrial fibrillation; 3. Patients with atrial fibrillation after thyroid abnormalities have been controlled (better after 6 months of control). The above-mentioned part of patients with mild underlying heart disease, relatively speaking, atrial fibrillation may bring greater harm, and the implementation of radiofrequency ablation has low risk and high benefit, so it is recommended that radiofrequency ablation is preferred for these types of patients. Indications for radiofrequency ablation: atrial fibrillation in combination with coronary artery disease, after adequate anti-myocardial ischemic treatment; 1. patients with atrial fibrillation in combination with hypertrophic cardiomyopathy; 2. patients with atrial fibrillation after valve replacement for rheumatic valve disease; 3. patients with atrial fibrillation in combination with heart failure. These types of patients have more serious heart disease combined with high surgical risk, but atrial fibrillation brings a greater risk of hemodynamic disturbance for these types of patients, and is also used as an indication for radiofrequency ablation in experienced atrial fibrillation centers, considering that atrial fibrillation may bring great benefit to patients after correction. Risks of atrial fibrillation procedures? Overall, radiofrequency ablation of atrial fibrillation catheters is a relatively safe procedure. However, as with other invasive procedures, there are risks associated with atrial fibrillation radiofrequency ablation. The most serious complications include: 1. Pericardial tamponade: i.e., perforation of the atrium during the procedure. Although this complication is dangerous, it can be lifted by pericardial puncture and drainage or surgical hemostasis; 2, cerebral infarction: the cause is mainly due to intraoperative or postoperative dislodgement of thrombus in the patient’s atrium before surgery, or because the mechanical contraction function of the atrium has not fully recovered after surgery, resulting in thrombus formation. This complication can be reduced by strict and careful transesophageal echocardiography and perioperative anticoagulation before surgery; 3. Left atrial-esophageal fistula: this complication has a high mortality rate once it occurs, but in experienced centers, the incidence of this complication is very low. All three complications mentioned above can be reduced by some precautions and can be remedied to reduce patient mortality.