What is atrial fibrillation? Under normal circumstances, the heart’s excitation begins in the sinus node, which emits regular electrical excitation (60-100 beats/minute) that travels sequentially through the atria and atrioventricular nodes to the ventricles, causing the entire heart to contract and diastole in a regular and coordinated manner, thus ensuring the heart’s pumping function to meet the body’s needs. Atrial fibrillation, short for atrial fibrillation, is an extremely common form of rapid arrhythmia. In atrial fibrillation, the direction of excitation in the atria is inconsistent and the frequency is fast and irregular, which deprives the atria of effective contraction. In atrial fibrillation, the atrial excitation frequency 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 not only much faster than the normal sinus heart rate, but also has an absolutely irregular rhythm. Studies have shown that there are about 10 million patients with atrial fibrillation in China, and the prevalence of atrial fibrillation in adults ranges from 1% to 6%, and the prevalence of atrial fibrillation increases sharply with age, and has even reached 10% in people over 75 years of age. What are the causes of atrial fibrillation? Diseases or factors associated with atrial fibrillation include: hypertension, coronary artery disease, cardiac surgery, valve disease, chronic lung disease, heart failure, cardiomyopathy, congenital heart disease, pulmonary embolism, hyperthyroidism, pericarditis, combination of other types of arrhythmias, alcohol abuse or addiction, chronic stress, electrolyte or metabolic imbalances, and severe infections. However, 6-15% of patients with atrial fibrillation have no known underlying cardiac disease on clinical examination and no other common trigger for atrial fibrillation, which is also known as idiopathic atrial fibrillation. What are the symptoms of atrial fibrillation? 1. palpitations: feeling a disturbance in the heartbeat or a rapid heartbeat 2. physical fatigue or feeling easily tired 3. vertigo: dizziness or fainting 4. chest discomfort: pain, pressure or discomfort 5. shortness of breath: feeling breathless during light physical activity or at rest 6. symptoms that trigger or exacerbate a coexisting heart condition, such as angina or heart failure Special Note: Although some patients with atrial fibrillation may have no symptoms at all, or only mildly non-symptomatic symptoms, some patients with atrial fibrillation may have no symptoms at all. or have only mildly non-symptomatic symptoms, the potential danger of atrial fibrillation – thromboembolic complications – is still present! What are the types of atrial fibrillation? According to the characteristics of atrial fibrillation episodes and the response to resuscitation therapy, there are four main types: 1. Primary atrial fibrillation: Atrial fibrillation with no previous history of atrial fibrillation, detected for the first time 2. Paroxysmal atrial fibrillation: Those who convert to sinus rhythm on their own within 7 days, generally lasting < 48< span=""> hours 3. Persistent atrial fibrillation: Those who last for more than 7 days and require drugs or electric shocks to convert to sinus rhythm 4. Long-range Persistent atrial fibrillation: atrial fibrillation lasting more than 1 year How to diagnose atrial fibrillation? The diagnosis of atrial fibrillation is not difficult. The electrocardiogram during an episode of atrial fibrillation is the basis for the diagnosis. If the episodes are brief and frequent, an ambulatory electrocardiogram can be performed to confirm the diagnosis. What are the risks of atrial fibrillation? 1, thrombosis and embolism, is the most serious harm of atrial fibrillation! In atrial fibrillation, the atria lose their contraction function, so the blood is easily stagnated in the atria and thrombus is formed. If the thrombus is dislodged, it can travel throughout the body with the blood, leading to cerebral embolism (stroke, hemiplegia) and arterial embolism of the limbs (serious cases even require amputation). The incidence of thromboembolic events in patients with atrial fibrillation is 5 to 17 times higher than normal. The annual stroke rate in non-valvular atrial fibrillation patients without anticoagulation is 5.3%, and at least 35% of patients will have at least one stroke in their lifetime. Stroke has a high rate of disability and mortality, and there is a lack of effective treatment at this stage. Risk factors for stroke in patients with atrial fibrillation include a history of previous embolism, combined hypertension, diabetes mellitus, heart failure, or age over 75 years. 3, Fast heart rate and irregular rhythm can make patients feel palpitations and significantly reduce their quality of life. 4. Loss of atrial systolic function and prolonged increase in heart rate cause tachycardia cardiomyopathy, which can lead to or aggravate heart failure. 5. Atrial fibrillation itself can increase mortality (2 times that of healthy people). What are the goals of atrial fibrillation treatment? The goals of atrial fibrillation treatment at this stage are: 1. To restore the atrial fibrillation rhythm and maintain it in sinus rhythm for a long time. 2. To control the rapid ventricular rate during atrial fibrillation episodes and improve the patient’s quality of life. 3. Preventing thromboembolic or stroke complications of atrial fibrillation is a preventive measure. What are the current treatment options for atrial fibrillation? The current treatment strategies for atrial fibrillation are mainly pharmacological and non-pharmacological. (1) to revert and maintain sinus rhythm, such drugs mainly include amiodarone (trade name: Kotarol), sotalol (trade name: Stavrosol), propafenone (trade name: Eflorn, cardioplegia), morethizine, etc. The side effects of long-term use of drugs to revert sinus rhythm are obvious or even increase the mortality rate, and the success rate of long-term treatment is only about 50% at most; (2) (2) control the rapid ventricular rate during atrial fibrillation, such as digoxin and beta-blockers (e.g., betalactam), calcium antagonists (e.g., Hersinol), etc. Controlling the ventricular rate can improve the symptoms but not the prognosis, and the risk of thromboembolism cannot be avoided because atrial fibrillation still exists; (3) anticoagulation therapy for patients at high risk of thromboembolism is a very effective and important treatment. The shortcoming of anticoagulation is that frequent blood tests are needed to reduce the risk of bleeding due to excessive anticoagulation or loss of prophylaxis due to insufficient anticoagulation. (2) Non-pharmacological treatment mainly includes: (1) electric resuscitation therapy: This is a method to convert atrial fibrillation to sinus rhythm by direct current electric shock, the advantage of which is the high success rate of conversion, the disadvantage is that it requires hospitalization and does not have the effect of maintaining sinus rhythm; (2) catheter radiofrequency ablation for atrial fibrillation, this procedure has been carried out for several years in the larger cardiac centers at home and abroad. Compared with traditional drug therapy, this procedure is minimally invasive and can achieve radical cure; (3) Surgery: Currently, it is mainly used for patients with atrial fibrillation who need cardiac surgery due to other heart diseases, and it is effective, but open-heart surgery is very traumatic. Certain diseases such as hyperthyroidism, acute alcohol, drugs, and stress-induced atrial fibrillation may disappear on their own after the cause is removed, but they can still persist. What is catheter radiofrequency ablation of atrial fibrillation? Studies have shown that at least 95% of paroxysmal atrial fibrillation is closely related to the pulmonary veins, usually four pulmonary veins in humans converge from the back of the heart into the left atrium, but in a few patients there can be more or less than 4. Catheter radiofrequency ablation is performed by delivering a 2.67 mm diameter cardiac catheter, similar to the diameter of an ordinary ballpoint pencil, into the atrium through the peripheral veins. High-frequency electromagnetic waves, or radiofrequency energy, are distributed at the junction site between the atria and the pulmonary veins, and ablated for one week along the opening of the pulmonary veins. The radiofrequency energy generates heat that raises the temperature of the surrounding tissues, forming a circular scar that confines the abnormal excitation that causes atrial fibrillation to the pulmonary veins so that it cannot be transmitted externally, thus achieving the goal of eradicating atrial fibrillation. In rare cases, some other sites within the heart (such as the superior vena cava) can also give off abnormal impulses, when these sites also need to be isolated. Which patients with atrial fibrillation can be treated with radiofrequency ablation? Patients with frequent episodes of paroxysmal atrial fibrillation or symptomatic persistent atrial fibrillation 2. Patients with atrial fibrillation who do not respond to medication or who do not want to take medication 3. Patients who cannot tolerate antiarrhythmic drugs or who experience serious side effects after medication 4. Patients with coexisting serious heart disease or hyperthyroidism (hyperthyroidism), sometimes it is necessary to treat the coexisting disease first so that the patient can tolerate the radiofrequency ablation procedure 5. Patients with permanent pacemakers, implantable cardioverter-defibrillators (ICDs) or prosthetic heart valves may also receive this treatment. 6. Note: Atrial fibrillation catheter radiofrequency ablation treatment requires hospitalization. Physician: 1) Systematic review of past medical history 2) Detailed physical examination 3) Routine blood, urine and stool tests, liver and kidney function and thyroid function tests 4) Electrocardiogram or ambulatory electrocardiogram 5) Transthoracic and transesophageal echocardiogram, the procedure should only be performed if there is no definite atrial thrombus 6) Cardiac MRI or CT to understand the anatomy of the atria and pulmonary veins 7) Briefing of you and your family on the procedure Through these examinations, the physician will discuss with you a treatment plan that is appropriate for you, especially to determine whether you are a candidate for catheter ablation, and will inform you and your family of the specific medical plan. For patients: Catheter ablation for atrial fibrillation requires hospitalization. Upon admission, please bring all your previous medical records and a list of medications you are currently taking. Consult with your physician before deciding whether to continue taking these medications. Do not stop taking your medication or add other medications on your own. If you are taking glucose-lowering medications, be sure to inform your doctor. Cooperate with your supervising physician to complete the preoperative examinations, relax and prepare for the procedure. Do not eat or drink for less than 6 hours before surgery. If you must drink because of medication, please try to take only a small sip of water. You should also avoid swallowing water when brushing your teeth and remove your dentures before surgery. What is the specific procedure? Atrial fibrillation catheter radiofrequency ablation is performed in the catheterization laboratory. The procedure begins with the patient lying flat on the catheter bed. The patient is prepared for the procedure with routine disinfection and draping (the neck, chest, arms and groin area will be disinfected). The surgeon delivers the catheter through the punctured vein to the heart. The vein selected for puncture is usually the bilateral femoral vein. Guided by x-ray, the catheter is delivered through the vein to the right atrium, and a relatively weak spot in the septum between the right and left atria is selected for puncture so that the catheter can enter the left atrium from the right atrium. Most septal punctures heal and close spontaneously after surgery. Since the pulmonary vein opens in the posterior wall of the left atrium, catheterization is performed primarily in the left atrium. The tip of the catheter can be manipulated for positioning, recording local cardiac electrical activity when placed against myocardial tissue, and also for intracardiac electrical stimulation. The tip of the catheter used for ablation delivers radiofrequency current to generate heat, which ablates the abnormal myocardial tissue causing the atrial fibrillation episode. This ablation has a coagulative necrotic effect on only a very small portion of the myocardial tissue and therefore causes minimal damage. We routinely use an advanced three-dimensional scaling system (CARTO system or ESI system) to reconstruct the three-dimensional configuration of the left atrium to guide the position of the ablation electrodes and to observe the integrity of the ablation pathway to improve the success rate of the procedure. How does the patient feel during the ablation procedure? You may experience a slight discomfort or burning sensation in the chest during the ablation procedure. The surgeon will administer intravenous sedatives or analgesics to reduce your discomfort. What testing facilities are needed during the procedure? The main monitoring facilities used include: Defibrillator/ Resuscitator: to help reverse a rapid heart rate ECG monitoring Sphygmomanometer to measure blood pressure Labelling system: to assist the surgeon in locating the origin of abnormal excitation Radiofrequency Ablation: to ablate arrhythmias Oximeter: to measure blood oxygen saturation X-ray digital subtractor: to observe the ablation process through imaging Atrial fibrillation catheter What are the success rates and risks of ablation? Regression and success rate after catheter radiofrequency ablation of atrial fibrillation: Approximately 70% of paroxysmal atrial fibrillation and 60% of persistent/permanent atrial fibrillation return to normal (sinus) rhythm after 3 months of a single ablation; success rate of up to 90% after a second or third ablation. Risks: Transcatheter radiofrequency ablation of atrial fibrillation is relatively safe. However, as with other invasive procedures, there are some risks associated with this treatment. The risks associated with the procedure will be carefully explained to you before the procedure. During the procedure, the surgeon will take the utmost responsibility and take precautions to minimize the risks of the procedure. It is especially important to emphasize that atrial fibrillation catheter ablation is a treatment technique that requires a high level of operator experience, so it is recommended that you seek treatment at an experienced center whenever possible. The procedure usually lasts 2 to 4 hours. Do I need sutures at the end of the procedure? At the end of the procedure, the surgeon will remove the catheter and apply pressure to the puncture site to prevent bleeding. Post-operative rest for 6-8 hours and hospitalization for observation is usually required for about 2 days. Long-term bed rest is not required and appropriate activities (such as walking) can be done to help restore body functions, but strenuous activities should be avoided. What do I need to pay attention to after radiofrequency ablation of atrial fibrillation catheter? In addition to providing you with surgical treatment, your post-operative recovery will be included in our overall care. For this reason, we have developed a detailed post-operative medical plan to help you enjoy a “fibrillation-free” life. What will I feel after catheter ablation? You may experience weakness and chest discomfort for 48 hours after the procedure. If your symptoms are significantly worse or do not subside, please inform your doctor, who will treat the symptoms accordingly. How long do I need to stay in the hospital after surgery? After surgery, you will need to lie flat on your back and rest both lower limbs for 6-8 hours, and then you can get out of bed after 6-8 hours. Usually you can move normally 48 hours after surgery. Usually you need to stay for observation for about 2 days. Do I still need to take medication after surgery? In addition to the other medications you normally take as part of your basic therapy, you may still need to take an antiarrhythmic medication for the first three months after discharge from the hospital following catheter ablation, and then stop at three months if there is no recurrence of atrial fibrillation. In addition, you may still need to take the anticoagulant drug warfarin for a period of time because atrial function may not be restored immediately after the procedure due to the presence of atrial myocardial stenosis and the possibility of thrombus formation. The anticoagulant warfarin should be stopped only after the absence of atrial fibrillation has been confirmed by an ECG and self-reported symptoms, so frequent and timely contact between you and us is needed to determine whether to continue warfarin. What tests are needed after surgery? If you are taking amiodarone (cortolone), you will need to have your thyroid function and liver function reviewed regularly (at least once every 2 months). If you are taking warfarin, you will need to have your INR (International Normal Ratio in Chinese) tested 3 days after discharge from the hospital and the dose and next test will be determined based on the test results. If you are taking a new medication or have a large dietary adjustment, you will need to have your INR tested more often. Because you are applying warfarin to reduce the incidence of thromboembolism, the INR target is 1.8 to 2.5 (not the normal range on the labs) Precautions after going home: Do not swim for five days after going home, take a shower if possible, and avoid tub baths. Keep the puncture site clean and dry. Please inform us by mail or fax or telephone with a copy of the laboratory and test results so that we can analyze the cause and formulate a treatment plan for you. What about early postoperative recurrence? Because it takes time to repair the damage to the left atrium caused by radiofrequency energy, 40-50% of patients may have a recurrence of atrial tachycardia, atrial flutter or atrial fibrillation within 3 months after a single ablation. The atrial tachycardia and atrial flutter episodes with regular atrial excitation are the manifestation of disordered atrial excitation in atrial fibrillation modified by catheter ablation. Even if a recurrence occurs in the first 3 months after the procedure, you have a 50% chance of success after 3 months. Therefore, if a recurrence occurs within 3 months, please do not worry and do not be anxious, but continue to take antiarrhythmic drugs as prescribed by your doctor, or apply electrical cardioversion as appropriate. 3 months later, if there is still an attack, you can consider another RF ablation. How is the success of the procedure determined? After 3 months, if you are still free of atrial fibrillation, atrial flutter and atrial tachycardia without taking any antiarrhythmic drugs, congratulations, the procedure is successful.