What is atrial fibrillation?
The heart beats in a normal rhythm, 60-100 beats per minute in most cases. Atrial fibrillation, short for atrial fibrillation, is an extremely common form of arrhythmia. In atrial fibrillation, the direction of excitation in the atria is inconsistent and the frequency is fast and irregular, which causes the atria to lose their effective contraction. In atrial fibrillation, the atrial excitation frequency is as high as 300 to 600 beats/min, but the atrial excitation cannot reach all the ventricles, so the heart rate can generally reach 100 to 200 beats/min. At this point we feel panic and shortness of breath.
Studies have shown that there may be as many as 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 dramatically with age, reaching 10% in people over 75 years old.
Why does atrial fibrillation occur?
Atrial fibrillation is often associated with other diseases such as hypertension, coronary artery disease, cardiac surgery, rheumatic heart disease, chronic lung disease, heart failure, cardiomyopathy, congenital heart disease, pulmonary embolism, hyperthyroidism, pericarditis, electrolyte or metabolic imbalance, and severe infections. Sometimes atrial fibrillation can also occur in the absence of other diseases and in the presence of alcoholism or alcohol addiction, chronic mental stress, and heavy consumption of stimulating beverages such as coffee. In 6-15% of patients with atrial fibrillation, clinical examination does not reveal any known underlying heart disease or other common causes of atrial fibrillation, which is also known as idiopathic atrial fibrillation.
What are the different types of atrial fibrillation?
Based on the characteristics of atrial fibrillation episodes and the response to resuscitation therapy, there are four main types as follows.
1. primary atrial fibrillation: atrial fibrillation with no previous history of atrial fibrillation and detected for the first time.
2, paroxysmal atrial fibrillation: those who convert to sinus rhythm on their own in 7 days
3, persistent atrial fibrillation: lasting more than 7 days, requiring drugs or electric shocks to convert to sinus rhythm.
4. Permanent atrial fibrillation: those who cannot be converted to sinus rhythm or those who recur within 24 hours after conversion.
The diagnosis of atrial fibrillation is not difficult, and the electrocardiogram during an episode of atrial fibrillation is the basis for the diagnosis. If the attack is brief and frequent, the diagnosis can be confirmed by ambulatory electrocardiography.
What are the risks of atrial fibrillation?
Thrombosis and embolism are the most serious dangers of atrial fibrillation! In atrial fibrillation, the atria lose their ability to contract effectively, so blood tends to stagnate in the atria and form thrombi. If the thrombus is dislodged, it can travel throughout the body, leading to cerebral thrombosis (stroke, hemiplegia), arterial embolism of the limbs (in severe cases, even amputation), etc. The incidence of thromboembolic events in patients with atrial fibrillation is 5 to 17 times higher than in raw normals. 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 at this stage there is a lack of specific treatment. Thrombosis is likely to occur if there is a previous history of embolism, hypertension, diabetes, coronary artery disease, heart failure, left atrial enlargement, or age over 65 years.
Rapid heart rate and irregular rhythm can cause panic and significantly reduce the patient’s quality of life, and loss of atrial systolic function and prolonged rapid heart rate cause tachycardia cardiomyopathy, which can lead to heart failure, manifested by weakness and reduced mobility.
Atrial fibrillation itself can increase mortality (twice as much as in a healthy population)
What are the goals of atrial fibrillation treatment?
The goals of atrial fibrillation treatment at this stage are
1. To restore atrial fibrillation rhythm and maintain it in sinus rhythm for a long period of time.
2. To control the rapid ventricular rate during atrial fibrillation episodes and improve the quality of life of the patients.
3.Prevent thromboembolism or stroke complications of atrial fibrillation.
4.What are the current treatment methods for atrial fibrillation?
The current treatment strategy of atrial fibrillation mainly includes: pharmacological treatment and non-pharmacological treatment.
Pharmacological treatment mainly includes.
(1) to restore and maintain sinus rhythm, these drugs are mainly ibrit, amiodarone (trade name: up to the dragon), sotalol (trade name: Stacor), propafenone (trade name: Eflorn, heart rhythm), morethizine, etc., the side effects of long-term use of drugs to restore sinus rhythm are obvious or increase the mortality rate, and the success rate of treatment is only about 30% at most;
(2) To control the rapid ventricular rate during atrial fibrillation episodes, these drugs include digoxin, ß-blockers (e.g., betalactam) and calcium antagonists (e.g., Heparin, Isoptin), which can improve symptoms but not prognosis;
(3) Anticoagulation is essential for patients at high risk of thromboembolism. Anticoagulation requires frequent blood tests to minimize bleeding due to over-anticoagulation or loss of prophylaxis due to under-anticoagulation.
The main non-pharmacological treatments include.
(1) Electrical resuscitation therapy: This is a method of converting atrial fibrillation to sinus rhythm by means of direct current electroshock. The advantage of this is the high success rate of conversion, but the disadvantage is that it requires adequate hypnotic sedation and does not have the effect of maintaining sinus rhythm.
(2) Catheter radiofrequency ablation for the radical treatment of atrial fibrillation, which has been performed for more than a decade in larger cardiac centers in China and abroad. Compared to conventional drug therapy, this procedure is minimally invasive and can achieve a radical cure. In the world guidelines, catheter ablation is already a Class I treatment modality for atrial fibrillation.
(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 itself is more invasive.
Atrial fibrillation due to certain diseases such as hyperthyroidism, acute alcoholism, drugs, and stress may disappear on its own or may persist after the cause is removed.
What is catheter radiofrequency ablation of atrial fibrillation?
Studies have shown that at least about 95% of atrial fibrillation is closely related to the pulmonary veins. Typically a person has four pulmonary veins that converge from the back of the heart into the left atrium; a few patients can have more or less than four. Catheterized radiofrequency ablation is performed by sending a catheter of the diameter of an ordinary ballpoint pencil through a vein in the thigh into the atrium, which distributes high-frequency electromagnetic waves, or radiofrequency energy, at the site where the atrium joins the pulmonary veins, ablating a week along the opening of the pulmonary veins. The radiofrequency energy generates heat that raises the temperature of the surrounding tissue, forming a circular scar and eventually causing the atrium to lose electrical contact with the pulmonary veins, thus achieving the goal of eradicating atrial fibrillation. In rare cases, some other areas within the heart (such as the superior vena cava) can also give off abnormal impulses, and these areas also need to be isolated in this case.
How does the procedure work?
Radiofrequency ablation of atrial fibrillation catheters is performed in the catheterization laboratory. There is no general anesthesia and no incision is required. The procedure begins with the patient lying flat on the catheter bed and is prepared by routine disinfection and draping (the neck, chest, arms and groin area will be disinfected). Under the direction of an X-ray, a catheter is delivered through a vein to the right atrium. A septum, called the atrial septum, is created between the right and left atria, and a small hole is made in the septum so that the catheter can enter the left atrium from the right atrium, which is the site the surgeon will treat. The atrial septal puncture hole can heal and close naturally after the procedure. The tip of the catheter can be manipulated to position itself against the myocardial tissue to record local electrical activity of the heart, and to perform electrical stimulation within the heart. The tip of the catheter used for ablation delivers radiofrequency current to generate heat, which in turn ablates the abnormal myocardial tissue causing the atrial fibrillation episode. This ablation produces coagulative necrosis in only a small percentage of the myocardial tissue and therefore causes minimal damage. We routinely use an advanced 3-D scaler system (EnSite System) to reconstruct the anatomy of the left atrium to know the location of the ablation electrodes and to observe the integrity of the ablation pathway, improving the success rate of the procedure.
How long does the ablation procedure take?
The entire procedure usually takes about 2-4 hours. The procedure time is relatively short for paroxysmal atrial fibrillation and longer for persistent atrial fibrillation. Of course, the time required for the procedure varies depending on the specific circumstances of the procedure.
What is the success rate of atrial fibrillation catheter ablation? Are there any risks?
Post-radiofibrillation catheter ablation regression and success rates.
Within 3 months after a single ablation, approximately 40% to 50% of patients may experience a recurrence of atrial tachycardia, atrial flutter, or atrial fibrillation, but approximately 80% of paroxysmal atrial fibrillation and 70% of persistent/permanent atrial fibrillation may return to normal (sinus) rhythm after 3 months. If the patient still has episodes of atrial tachycardia, atrial flutter, or atrial fibrillation after 3 months, the patient is considered unsuccessful, with a success rate of 90% after a second or third ablation.
Riskiness.
Transcatheter radiofrequency ablation therapy for atrial fibrillation is relatively safe. However, as with some 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 do his best to be responsible 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 experience, so it is recommended that you go to an experienced atrial fibrillation center for treatment whenever possible.
What should I expect after AF surgery?
In addition to providing you with surgical treatment, 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 persist, please inform your doctor, who will treat the symptoms as appropriate.
After surgery, you will need to lie down and rest both lower extremities for 12 hours, after which you can get out of bed. Normal activities are usually possible 48 hours after surgery. Usually hospitalization is 3-5 days for observation.
Do I need to take medication after surgery?
In addition to the other medications you normally take as part of your basic therapy, you will need to take an antiarrhythmic medication for the first three months after the catheter ablation (this may be one of cortolone, cardioplegia, sotalol, betalocort, or morethizide, depending on your condition). If there is no recurrence of atrial fibrillation, stop it at three months.
In addition, you will also need to take the anticoagulant drug warfarin for a period of time because most of the function of the atria does not recover immediately after surgery and there is still a possibility of forming blood clots. The anticoagulant drug warfarin can be discontinued only after one month of discontinuation of the antiarrhythmic drugs and after the absence of atrial fibrillation has been confirmed by ambulatory electrocardiogram and conscious symptoms, so frequent contact between you and us is needed to determine whether to continue warfarin.
What tests do I need to have after surgery?
If you are taking amiodarone (cortisone), you will need to have your thyroid and liver function reviewed regularly (at least once every 2 months). If you are taking warfarin, your INR will be tested 3 days after discharge from the hospital and the dose and next test will be determined based on the results of the test. Many medications and foods can affect the anticoagulant effect of warfarin and make it difficult to smooth out the INR. The goal for INR is 1.8 to 2.5 (rather than the normal range on the labs).
Electrocardiogram and ambulatory ECG are required every month for three months after surgery, or anytime if there are palpitations and other discomfort. A repeat echocardiogram is required three months after surgery to determine whether atrial function has fully recovered and whether the diameter of the left atrium has shrunk.
What about early postoperative recurrence?
Because it takes time to repair the damage caused by radiofrequency energy to the left atrium, there is a risk of recurrence of atrial tachycardia, atrial flutter or atrial fibrillation in 40% to 50% of patients within 3 months after a single ablation. Even if there is a recurrence within the first 3 months after the operation, please do not worry and be anxious, you should continue to take antiarrhythmic drugs as prescribed by your doctor or apply electric cardioversion according to the situation. 3 months later, if there is still an attack, the initial operation is considered unsatisfactory and radiofrequency ablation can be performed again, according to large-scale statistics, the success rate of the operation can be as high as 90%.
How is the success of the procedure determined?
After 3 months, if you are still free of atrial fibrillation, atrial flutter or atrial tachycardia without taking any antiarrhythmic drugs, then congratulations, the initial results of the surgery are successful.