rule, which deprives the atria of effective contraction and can lead to a 20-30% reduction in cardiac functional reserve in patients with atrial fibrillation. Without medication, the ventricular rate (heart rate) in atrial fibrillation can reach 100-160 beats per minute or even faster, and the rhythm of the ventricular contractions is definitely irregular, which can lead to more pronounced symptoms. What are the symptoms of atrial fibrillation? Most of the symptoms when atrial fibrillation occurs for the first time are as follows: the attack starts rather suddenly, and the patient feels palpitations, shortness of breath, discomfort in the precordial area, anxiety, irritability, and fidgeting. Patients with underlying heart disease (e.g. coronary heart disease, cardiomyopathy, cardiac insufficiency) can experience angina pectoris, dizziness, or even fainting due to the fast and irregular ventricular rate during atrial fibrillation episodes, and sometimes heart failure and shock can occur. The duration of each episode of atrial fibrillation varies, with short episodes lasting only a few minutes, but frequent episodes can occur, and long episodes can last for several days to several weeks. The severity of symptoms when atrial fibrillation occurs is also affected by individual differences (e.g., the patient’s sensitivity to perceive and tolerate the symptoms). Some patients may have obvious symptoms when atrial fibrillation first occurs, and as the course of the disease is prolonged, some patients may gradually adapt to it, and their symptoms may gradually diminish or even disappear. If there is no other heart disease and the heartbeat is basically close to normal during atrial fibrillation, some patients may have no symptoms at all. Symptoms in patients with persistent atrial fibrillation are related to the extent of the patient’s pre-existing heart disease and the patient’s ventricular rate during atrial fibrillation. The main manifestations are: palpitations, chest tightness, chest pain, shortness of breath, especially when the ventricular rate increases significantly after activity, activity endurance is significantly reduced. People with persistent atrial fibrillation are prone to heart failure. What are the causes and classifications of atrial fibrillation? Diseases or factors associated with atrial fibrillation include: high blood pressure, coronary artery disease, cardiac surgery, valvular disease, chronic lung disease, heart failure, cardiomyopathy, congenital heart disease, pulmonary embolism, hyperthyroidism, pericarditis, combinations of other types of arrhythmia, alcoholism or alcoholism, prolonged stress, electrolyte or metabolic imbalances, and severe infections. However, 6%-15% of patients with atrial fibrillation do not have any known underlying cardiac disease on clinical examination, nor do they have other common triggers of atrial fibrillation, which is called idiopathic atrial fibrillation. According to the current European and American guidelines and the classification criteria developed by the expert consensus, atrial fibrillation can be divided into: 1, paroxysmal atrial fibrillation: can be terminated by itself within 7 days, reversion to sinus rhythm (normal heartbeat rhythm), the general duration of <48 hours; 2, persistent atrial fibrillation: lasts for more than 7 days, requiring drugs or electrical resuscitation in order to be converted to sinus rhythm; 3, permanent atrial fibrillation: can not be converted to sinus rhythm due to various reasons, or the doctor and the patient has been receiving atrial fibrillation. Atrial fibrillation: atrial fibrillation lasting more than 1 year and considered for resumption of sinus rhythm; 4. Long-term persistent atrial fibrillation: atrial fibrillation lasting more than 1 year and considered for resumption of sinus rhythm. Types 2-4 of atrial fibrillation classification can also usually be generalized as chronic atrial fibrillation. What are the dangers of atrial fibrillation? According to statistics, the prevalence of atrial fibrillation in the population is close to 1%, and according to this calculation, the number of atrial fibrillation patients in China may be as high as 13 million. Atrial fibrillation is not only common, but also harmful, which can seriously affect the quality of life of the patients, and at the same time greatly increase the mortality rate of the patients and the incidence of stroke. Thrombosis and embolism are the most serious hazards of AF. When atrial fibrillation occurs, blood tends to stagnate in the atria due to the loss of atrial contraction and thrombus formation. If a thrombus is dislodged, it can travel with the blood throughout the body, leading to cerebral embolism (stroke, hemiplegia), limb arterial embolism (even amputation in severe cases), and so on. The incidence of thromboembolic events in patients with atrial fibrillation is 5-17 times higher than in normal people. The annual incidence of stroke without anticoagulation in patients with nonvalvular atrial fibrillation is 5.3%, and at least 35% of patients have at least one stroke in their lifetime. Stroke is associated with a high rate of disability and mortality, and there is a lack of effective treatment. Risk factors for stroke in patients with atrial fibrillation include a history of previous embolism, comorbid hypertension, diabetes mellitus, heart failure, or age over 75 years. Excessive ventricular rate and rhythm irregularity during an AF episode can cause patients to feel palpitations and chest tightness, shortness of breath, irritability, and fidgeting, which can significantly reduce their quality of life. Loss of atrial systolic function and prolonged heart rate increase can cause tachycardia, which can lead to or aggravate heart failure. In addition, atrial fibrillation itself can increase the mortality rate of patients (two times that of the healthy population). What are the goals and methods of treatment of atrial fibrillation? There are three main goals: 1) to reverse the atrial rhythm, so that patients with atrial fibrillation can regain and maintain normal sinus rhythm for a long period of time; 2) to control the rapid ventricular rate during atrial fibrillation episodes, so as to improve the patient's quality of life; and 3) to prevent the formation of blood clots and embolisms caused by atrial fibrillation, so as to avoid serious complications such as strokes and other thromboembolic complications. At present, the treatment of atrial fibrillation mainly consists of drug therapy and non-drug therapy. 1, drug therapy mainly includes: (1) reversal and maintenance of sinus rhythm: these drugs are mainly amiodarone, propafenone, sotalol, moresizine and so on. If the drugs to restore sinus rhythm are taken for a long period of time, the chances of side effects increase significantly, and even increase the mortality rate of the patients, and the arrhythmogenic effect of the drugs and extracardiac adverse reactions are also common. Even more disappointing is that, despite this, the success rate of drug resumption and long-term maintenance of sinus rhythm can only reach about 50% at most. (2) Control of rapid ventricular rate during episodes of atrial fibrillation: The main drugs in this category are digoxin, beta-blockers (e.g., metoprolol, etc.), and calcium antagonists (e.g., diltiazem, etc.). Ventricular rate control therapy improves the symptoms of atrial fibrillation and is not inferior in prognosis to reversal and maintenance of sinus rhythm therapy, but because atrial fibrillation remains, there is still a risk of thrombosis and embolism. (3) Anticoagulation for atrial fibrillation: It is a very important part of the treatment of atrial fibrillation. For patients at high risk of thromboembolism, rheumatic heart valve disease with atrial fibrillation patients, in addition to contraindications to anticoagulation, should be long-term oral anticoagulation therapy with warfarin. Warfarin can effectively reduce thrombosis and avoid embolism, but its efficacy is susceptible to the influence of food and drugs, and regular blood sampling is needed to monitor the international normalized ratio (INR) to prevent over-anticoagulation and under-anticoagulation. The maximum protection against ischemic stroke can be obtained when the range of INR is 2.0-3.0. Non-pharmacological treatments mainly include: (1) electrical cardioversion therapy: it is a method of direct current shock to convert atrial fibrillation to sinus rhythm, the advantage of which is a high success rate of reversal, the disadvantage of which is that hospitalization is required to monitor the treatment and it may be difficult to maintain sinus rhythm for a long period of time. (2) Catheter radiofrequency ablation for atrial fibrillation: It is a minimally invasive catheter-based surgery, which has been carried out for more than ten years in many large cardiac centers at home and abroad. It has been proved that, compared with the traditional drug therapy, catheter radiofrequency ablation has a high success rate in the treatment of atrial fibrillation, and most of the patients are able to achieve the eradication of atrial fibrillation and the maintenance of a normal sinus rhythm for a long period of time after the surgery. Moreover, the surgery is less traumatic and safer, and normal activities can be resumed on the second day after the surgery, so it has become the preferred treatment method for atrial fibrillation. (3) Cardiac Surgery: Surgeons utilize radiofrequency and microwave energy to ablate atrial fibrillation under direct vision. Compared with catheterized radiofrequency ablation for atrial fibrillation, the surgery is more traumatic, sometimes even requiring open chest surgery, and the postoperative recovery time is long. At present, it is mainly used for atrial fibrillation combined with heart diseases that require surgical treatment, such as heart valve replacement, bypass grafting, congenital heart disease and other heart surgeries at the same time for cardiac surgery to treat atrial fibrillation. What is atrial fibrillation catheter radiofrequency ablation? Typically humans have four pulmonary veins converging from the back of the left atrium of the heart, and a small number of patients may have more or less than four pulmonary veins. Some studies have shown that there is a strong relationship between paroxysmal atrial fibrillation and the pulmonary veins in the left atrium in at least about 95% of cases. Catheter radiofrequency ablation is a procedure in which a radiofrequency ablation catheter is delivered to the left atrium through a peripheral venous vessel, and radiofrequency energy is delivered to the site where the atrium connects with the pulmonary veins, and ablated along the opening of the pulmonary veins for one week. The radiofrequency energy generates heat that causes the temperature of the surrounding atrial musculature to rise (usually no more than 40 degrees Celsius), creating a ring-shaped scar, which blocks the abnormal excitation of the pulmonary veins that causes the onset of atrial fibrillation in the pulmonary veins, so that the veins cannot conduct to the left atrium. cannot be transmitted to the left atrium, thus eradicating AF. In rare cases, other parts of the heart (e.g., the superior vena cava) can also emit abnormal excitation, so these parts also need to be isolated and blocked after electrophysiologic labeling. Radiofrequency ablation of persistent atrial fibrillation is more complex, and in addition to the ablation of the sites described above (pulmonary veins-left atrium), linear ablation of sites within the left atrium, such as the apex of the atrium, and the mitral annulus to the left inferior pulmonary vein (mitral isthmus), is also required. Sometimes, ablation of the tricuspid isthmus of the right atrium (linear ablation of the tricuspid annulus to the inferior vena cava) is also required in patients who have had atrial fibrillation with atrial flutter in the past or to avoid episodes of atrial flutter after the procedure. Currently, catheter radiofrequency ablation is guided using an advanced electroanatomical landmarking system (CARTO system), which is capable of reconstructing the three-dimensional configuration of the left atrium, thus guiding the placement of the ablation catheter or electrodes, and observing whether the ablation trajectory is intact or not, ensuring the success rate of the procedure. Since 2006, our hospital has been carrying out transcatheter radiofrequency ablation for atrial fibrillation under the guidance of electroanatomical labeling system (CARTO system), and we have accumulated rich clinical experience in this area, which can provide safe and effective surgical treatment for the majority of patients with atrial fibrillation.