Atrial fibrillation is one of the most common clinical arrhythmias. The following is a brief description of the most representative issues of concern to patients, in the hope that it will be helpful to the majority of patients.
1.Why do you get atrial fibrillation?
Atrial fibrillation is, after all, an abnormal electrical activity in the atria due to various causes of fibrosis, and, due to anatomical characteristics, the majority of them occur in the left atrium. In general, the development of atrial fibrillation mostly goes through a process of atrial precontraction (premature atrial beats) – atrial tachycardia – atrial flutter – paroxysmal atrial fibrillation – persistent atrial fibrillation. Of course, the progression of this process varies from person to person; some people may take decades, while others reach the stage of persistent AF within a short period of time. Overall, everyone has the potential to develop AF if they live a long enough life. There are many causes of atrial fibrillation, including genetic variants, hyperthyroidism, coronary artery disease, hypertension, diabetes, cardiomyopathy, and other diseases. Chronic alcohol consumption, overexertion, and smoking are also common causes. Some patients will have attacks at a younger age, the youngest even in their teens. Generally speaking, the earlier the onset, the greater the relationship with genetic mutations. In recent years, AF caused by chronic alcohol abuse has become more common, and this type of AF is more difficult to treat. Most patients with atrial fibrillation often do not have a single clear clinical cause, a condition we call idiopathic atrial fibrillation. Some patients will develop atrial fibrillation early after undergoing cardiac surgery, but this atrial fibrillation is often caused by heart surgery, and may disappear for a long time afterwards without further attacks.
2. What are the symptoms and dangers of atrial fibrillation?
The symptoms of atrial fibrillation vary from person to person. The most common is panic and heartbeat. Some people may feel tightness in the chest, shortness of breath or sweating. Some people will have polyuria, followed by longer periods of self-conscious weakness due to low potassium. However, these symptoms are highly variable, and many people often have symptoms this episode and then seem to have them less pronounced the next time, or even some people (especially men) only find atrial fibrillation by chance during a routine physical exam or a visit for another condition. A more common type of atrial fibrillation is a slow heartbeat, but a fast heartbeat during an atrial fibrillation attack, which we call slow-fast syndrome. The reason for this is that there are two atria: the right atrium has the sinus node, which is responsible for the normal heartbeat, and if there is a fibrotic lesion in the right atrium, it leads to a decrease in the function of the sinus node and sinus bradycardia or sinus arrest, while a fibrotic lesion in the left atrium leads to atrial tachycardia, atrial flutter and atrial fibrillation. Most patients have atrial fibrillation that tends to flare up after exertion, alcohol consumption, and at night, but this attack pattern is usually not fixed and is not important for diagnostic treatment. Some patients think that the trigger and regularity of the onset is important, but in fact it is not very significant for treatment.
The most serious danger of atrial fibrillation is that it leads to cerebral infarction, also called stroke. A few people may also suffer from heart failure due to atrial fibrillation, unable to breathe, unable to lie flat, swollen feet, etc., mainly because the ventricular rate is not effectively controlled when atrial fibrillation is too fast. Clinically, some patients have no obvious symptoms, and atrial fibrillation is only discovered by chance during physical examination, which is called asymptomatic atrial fibrillation. In a sense, asymptomatic atrial fibrillation may be more dangerous than symptomatic atrial fibrillation, because asymptomatic will not be treated in time, then the possibility of stroke or heart failure is higher, and many patients are found to have atrial fibrillation only after the occurrence of cerebral infarction, which causes great regret. Some patients may die or become disabled as a result.
3, how to diagnose atrial fibrillation?
The diagnosis of atrial fibrillation is very easy, as long as the attack is captured by general electrocardiogram or ambulatory electrocardiogram, the diagnosis can be confirmed without special tests. However, cardiac ultrasound, ECG and blood tests can be done to find out if other conditions are combined. If atrial fibrillation starts and stops on its own without medication, it is called paroxysmal atrial fibrillation, and if the attack cannot be stopped without medication or even if medication is ineffective, it is called persistent atrial fibrillation. If it lasts for a long time and cannot be reversed even with drugs and electrical resuscitation, it is called permanent atrial fibrillation.
4.What medications are used to treat atrial fibrillation?
The treatment of atrial fibrillation is a difficult problem. First, you should try to control it with medication. You need to be guided by your doctor on exactly how to use the medication and find one that suits you. However, it must be clear that, at present, there are no medications that can eradicate atrial fibrillation, except for the few that are caused by hyperthyroidism or, pre-excitation syndrome, early post-operative cardiac surgery, etc., and may not recur after these conditions are resolved. However, it is true that medications may make some patients seizure-free or almost seizure-free for a considerable period of time. However, the atrial fibrillation lesion is still present and will continue to develop, and sooner or later, another attack will occur. Therefore, for atrial fibrillation, the use of medication is tantamount to “stabilization.” Some patients with mild symptoms, low risk of stroke, few attacks or advanced age, frail health, other serious illnesses, and poor economic conditions may choose to be treated conservatively with medication. If there has been a cerebral infarction or the doctor assesses that the risk of cerebral infarction is relatively high, the symptoms of the attack are more obvious and bring more stress to life and mental health, relatively young or the heart is dysfunctional due to atrial fibrillation, etc., these patients should consider catheter ablation for the eradication of atrial fibrillation.
5.What is catheter ablation for atrial fibrillation? How about cryoablation?
Catheter ablation for atrial fibrillation is a technique that has gained popularity in the last 20 years. In general, it is a safe and minimally invasive interventional treatment. However, unfortunately, the results of the current treatment are not particularly satisfactory. It is performed by delivering a catheter into the heart through a vascular puncture and destroying the lesion causing atrial fibrillation to achieve treatment. The surgical procedure has evolved several times, with the pulmonary vein large-loop isolation currently being the mainstay, but its drawbacks have been increasingly identified, mainly the difficulty in breaking the bottleneck in terms of success rate and worse long-term results. In paroxysmal atrial fibrillation, in general, the earlier the treatment, the better the outcome, but some patients may have severe atrial lesions shortly after onset. In the long term, the results of mainstream pulmonary vein isolation are not particularly satisfactory, especially in persistent AF, where the success rate over 5 years is currently reported abroad to be between 15-50% if a single ablation procedure is performed. Current pulmonary vein isolation is relatively limited in its scope of treatment and new lesions can develop as the disease progresses. Another important reason is that the ablation catheters currently used are difficult to create a safe and complete injury. Overall, the earlier the detection, the smaller the left atrium, and the less comorbid other disease, the better the outcome of the procedure. The success rate of a single procedure for paroxysmal atrial fibrillation can generally reach about 80% in high level centers, but persistent atrial fibrillation is generally about 30-50%, and most centers do not reach this level yet.
Our original linear ablation has the leading long-term success rate in the world, but for persistent atrial fibrillation, past experience shows that only close to 50% of patients are completely cured after 5 years of a single operation, and other patients can only achieve improvement. However, in the last year or two, due to technological advances and improved surgical instruments, our recent success rates have improved significantly, with paroxysmal atrial fibrillation exceeding 90% and persistent atrial fibrillation reaching a 1-year success rate of over 70%.
Atrial fibrillation ablation requires a relatively high level of skill in the hands of the surgeon, and excessive pursuit of results may lead to danger during the procedure, which in severe cases may result in heart rupture, stroke or even death. Especially in older patients with large left atrium and weakness, the risk of the procedure is higher, but the success rate is lower. If attention is paid to favoring the safety of the procedure, the ablation effect will be compromised again. Therefore, ultrasound ablation, laser ablation, microwave ablation and other modalities have emerged, but they have all been eliminated. At present, only frozen balloon ablation has a small number of applications, but its efficacy and safety are not superior compared with radiofrequency ablation, and there are more complications, but the superiority of freezing is that it requires less operating technique for surgeons, so it is especially welcomed by primary hospitals.
In recent years, a combined medical-surgical ablation model has emerged, which was pioneered by our Fu Wai Hospital and individual hospitals in Europe.
The so-called combined medical-surgical ablation means that most of the eligible patients will first undergo endocardial ablation in internal medicine by puncturing the blood vessels, and then generally observe the patients for at least 3 months after the procedure. If, after 3 months of catheter ablation, there are still frequent episodes, or even some patients become intractable left atrial flutter or atrial tachycardia, another ablation is required. In this case, we can consider the surgical option of thoracoscopic minimally invasive ablation of the epicardium, which achieves an “internal-external attack” and is generally more effective than endocardial ablation again, and the wound is not too large. On the other hand, some patients can only undergo surgical ablation or preferably surgical ablation first due to the combination of some special conditions, and then medical ablation if there is a recurrence.
It is worth pointing out that the cost of ablation of atrial fibrillation is currently relatively high, so repeated ablation is indeed a heavy burden for patients. So why is ablation necessary? Actually, it is not necessary to ablate when you have atrial fibrillation. Due to economic and other factors, the majority of atrial fibrillation is still treated conservatively with medications. The specific patients who are suitable for ablation and the specific ablation methods need to be determined by the doctor after visiting the hospital and informing the patient of the pros and cons.
As for cryoablation, unlike radiofrequency ablation, which destroys atrial fibrillation lesions through heating, it is achieved through cryogenic freezing. Since the human body is a constant temperature “big box”, it is not easy to freeze to the extent of cure. The main advantage of this technique is that it is beneficial to the physician, especially for those who have relatively little experience with radiofrequency catheter ablation, and who are less experienced and skilled in catheter manipulation, which is easier with the cryoballoon. Moreover, patients need to be irradiated with larger doses of radiation and injected with large doses of iodine contrast, and the cryo technique is currently only applicable to paroxysmal AF with relatively mild disease in the early stages of AF, and its effectiveness and safety are not as strong as radiofrequency ablation, with more complications. Cryoablation is not recommended for persistent atrial fibrillation.
6. Can pacemakers treat atrial fibrillation?
No. A pacemaker is a device that treats bradycardia by monitoring the heartbeat and giving the heart an electrical signal to beat when it is found to be bradycardic. Special pacing has been explored in the past to reduce atrial fibrillation episodes, but was ultimately found to be ineffective. Patients with atrial fibrillation have irregular heart rhythms, but the vast majority are on the fast side or generally average down in the normal range, so a pacemaker is not needed. In a small number of patients, who for various reasons have to choose medications to control AF, and some of whom have a heartbeat that stops for more than a few seconds after taking the medication, a pacemaker may need to be implanted to “bail them out”, but it is important to be cautious, because by stopping the medication or adjusting the dose, a pacemaker may not be needed. For those patients with slow heart rate and fast heart rate (often more than 120 beats per minute), there are two treatment options: one is to implant a pacemaker and take oral medication to control atrial fibrillation, which is usually suitable for older patients, those with poor health or those with advanced atrial fibrillation; the other is ablation therapy, which is usually performed in conjunction with ablation of the left atrial Over the years, we have observed that most of the patients have normalized their heart rate from bradycardia to normal, and atrial fibrillation has been cured or has basically stopped, thus killing two birds with one stone. It must be noted that AF is not so easily eradicated in some patients. In addition, for those patients whose heartbeat stops after the termination of atrial fibrillation episode leading to syncope, it is theoretically best to treat atrial fibrillation by ablation as well to kill two birds with one stone, otherwise a pacemaker can only be implanted to prevent fainting, but a pacemaker cannot cure or prevent atrial fibrillation.
7.What do I need to pay attention to after ablation of atrial fibrillation?
Ablation is not a permanent treatment for atrial fibrillation. Therefore, patients need to be patient for at least 3 months. Recurrence within the first 3 months is common and often requires medication to assist. Your doctor should give you detailed written instructions at the time of discharge, and after 3 months, it is up to you to decide whether you need another ablation. Of course, some patients may have a recurrence after many years and the doctor will need to decide if and when another ablation is needed. In the case of patients who have had pulmonary vein isolation, it is important to eat a soft diet in the early half of the year to avoid severe left atrial fistula, which is characterized by fever, syncope, and hemiparesis, a low incidence but very dangerous condition that requires immediate contact with the ablation surgeon. Some patients may experience shortness of breath after ablation, especially after activity, and the majority of patients experience relief after six months to a year. Patients who undergo cryoablation have a high rate of postoperative dyspnea due to phrenic nerve palsy, but most are able to recover. Individual patients can also suffer from gastroparesis due to vagus nerve damage, which manifests as vomiting and inability to eat, requiring prompt consultation for drainage.
8.If catheter ablation is not possible for various reasons and only medication is available for atrial fibrillation, what do I need to pay attention to?
At present, due to the high cost of atrial fibrillation ablation and the not particularly satisfactory effect, the majority of patients receive conservative treatment. This requires going to a regular hospital and following the standardized guidelines. The most important thing is to prevent a cerebral infarction, which requires a score given by the doctor after a thorough examination to determine exactly how high the risk of cerebral infarction/also a stroke is based on the score, and thus whether anticoagulation therapy is needed. In addition, patients with a rapid heart rate need to take medication to control their heart rate so that it does not affect their heart function by being too rapid for too long. Patients with cardiac insufficiency should not exceed 120 beats per minute on average, and patients with good heart function can tolerate even if they exceed 120 beats per minute for a few months. The use of anticoagulant drugs such as warfarin needs to be taken under the guidance of a doctor. Two new drugs have recently been approved by the state, dabigatran and rivaroxaban, which are relatively expensive, but are more convenient as they do not require blood tests.