I. What is atrial fibrillation (AF)?
Atrial fibrillation, as a cardiac arrhythmia, is an electrical abnormality in the atria. Unlike normal atrial electrical activity, which consists of regular electrical impulses from the sinus node and then coordinated contraction of the atria, atrial fibrillation presents a rapid disordered electrical activity in various parts of the atria, causing the atrial muscle to exhibit irregular fibrillation, and the frequency of the atria can reach 350-650 times/min. In this way, the atria are unable to perform normal systolic and diastolic activities.
Fortunately, the atrioventricular node acts as a gate at this time, which prevents the disorderly and rapid atrial electrical activity from being fully transmitted to the ventricles.
Second, what are the manifestations of atrial fibrillation?
Palpitations DD feel heartbeat, heartbeat disorder or heartbeat accelerated. Physical fatigue or exertion, quality of life decreases, and some patients urinate a lot during the attack. Vertigo DD dizziness and dizziness or fainting. Chest discomfort DD pain, pressure or discomfort. Shortness of breath DD feeling breathless during light physical activity or even at rest, with cardiac insufficiency. Thromboembolism DD causes ischemic necrosis of local tissues, which in severe cases causes stroke, hemiparesis, aphasia, intestinal necrosis, splenic embolism, renal embolism, lower limb artery embolism, etc. The most common site is cerebral embolism.
Although some patients may not have any sensation and symptoms (called asymptomatic atrial fibrillation), the hazards of atrial fibrillation still exist (such as cardiac insufficiency and thromboembolic complications), and some patients relax their vigilance because there are no obvious symptoms, thus delaying the disease.
Third, what are the types of atrial fibrillation?
Primary atrial fibrillation: Atrial fibrillation found for the first time, regardless of whether it has symptoms and can be self-reversed; paroxysmal atrial fibrillation: Atrial fibrillation lasting less than 7 days, usually less than 48 hours, mostly self-limiting; persistent atrial fibrillation: Atrial fibrillation lasting more than 7 days, persistent atrial fibrillation can be the first manifestation of arrhythmia, but also from the repeated episodes of paroxysmal atrial fibrillation developed into persistent atrial fibrillation. Persistent AF is generally not self-reversing, and the success rate of drug reversion is low.
Permanent (chronic) atrial fibrillation: Atrial fibrillation that lasts for more than 1 year and cannot be reversed by drugs, fails to be reversed by electrical resuscitation, or recurs within 24 hours after being reversed. It can be the first manifestation of atrial fibrillation or develop from repeated episodes of atrial fibrillation. Regardless of the type of atrial fibrillation, early treatment is important. The earlier atrial fibrillation is diagnosed and treated, the greater the chance of obtaining satisfactory treatment and cure.
Fourth, how is atrial fibrillation diagnosed?
Your doctor will suspect that you have atrial fibrillation when there is an irregular pulse. To confirm this diagnosis, further electrocardiographic examinations are needed, including a general electrocardiogram and a 24-hour ambulatory electrocardiogram (Holter), which is more significant for diagnosing arrhythmias because it is portable and more consistent with the patient’s heart rhythm in its normal physiological state.
An echocardiogram is also usually required to clarify the size of the chambers of the heart, the condition of the valves, and the systolic and diastolic function of the heart. In addition, in order to evaluate whether the patient is also combined with other causes or diseases, the doctor will take a detailed medical history, conduct a careful physical examination, and perform the necessary blood, urine, and other physical and chemical examinations.
V. What are the risks of atrial fibrillation?
Atrial fibrillation can greatly increase the risk of blood clots and strokes. As the atria lose their full and effective ejection function, blood is easily stagnated in the atria, which can lead to the formation of blood clots. Studies have shown that the incidence of stroke is six times higher in patients with atrial fibrillation than in normal subjects. The incidence is even higher for those patients over 65 years of age with a history of stroke or a history of hypertension, diabetes, or heart failure! Fast heart rate and irregular rhythm can cause patients to feel palpitations, chest tightness, dizziness, and even fainting.
Loss of atrial systolic function and prolonged increased heart rate can lead to cardiac enlargement and heart failure. Despite these risks, atrial fibrillation itself is not an immediate fatal condition. However, patients must face the symptoms and complications of atrial fibrillation and should receive further aggressive treatment, otherwise they may feel a significant decrease in quality of life.
How to prevent thromboembolism caused by atrial fibrillation?
A small percentage of patients can be prevented by taking oral aspirin. The vast majority of patients need to take Warfarin to prevent thromboembolism under the supervision of a physician, but regular blood sampling for INR monitoring is required for Warfarin, otherwise complications of visceral bleeding may occur. Patients who cannot tolerate warfarin or have contraindications to its use may undergo percutaneous left-ear occlusion. The elimination of AF itself by radiofrequency ablation is the most aggressive treatment.
VII. What are the mechanisms of atrial fibrillation?
The mechanisms of atrial fibrillation are currently considered to include the presence of a substrate for folding in the atria and an ectopic focal trigger mechanism. The ectopic focal trigger mechanism accounts for the majority of cases. The focal mechanism of atrial fibrillation refers to the development of atrial fibrillation from one or more confined sites (i.e., foci) that give off rapid excitation to induce an atrial fibrillation episode. The most common foci of atrial fibrillation are located at or near the pulmonary vein openings, which account for about 70-95% of all foci, or, to a lesser extent, at the posterior wall of the left atrium, the terminal ridge, and other sites.
Recent discoveries and understanding of the mechanism of focal onset of atrial fibrillation have opened up a new avenue for the eradication of the property. After removing the ectopic foci that initiate atrial fibrillation by transcatheter ablation or electrical isolation, about 90% of paroxysmal atrial fibrillation and 70% of persistent/permanent atrial fibrillation can be eliminated, and the frequency of atrial fibrillation episodes in some other patients is significantly reduced and the duration is significantly shortened, while atrial fibrillation is easier to control than before through medication-assisted treatment, which significantly improves the quality of life.
Eight, is atrial fibrillation curable?
What are the methods to eliminate atrial fibrillation? What are the advantages and disadvantages? Atrial fibrillation can be treated fundamentally! The current methods of eliminating atrial fibrillation include catheter ablation therapy and surgical treatment. Catheter ablation is suitable for most patients with atrial fibrillation. It is minimally invasive and easily accepted by the patient. Surgical procedures are currently used for patients with atrial fibrillation who require cardiac surgery for other heart conditions. Certain diseases such as hyperthyroidism, acute alcoholism, and drug-induced atrial fibrillation may disappear on their own or may persist after the cause is removed.
What is catheter-based radiofrequency ablation therapy for atrial fibrillation?
Although drugs are more commonly used, many patients are not satisfied with the results of treatment. In some patients, drug therapy is effective but the side effects of the drugs are not tolerated. The only safe and effective way to avoid surgery and cure atrial fibrillation is through catheter-based radiofrequency ablation. The catheter for radiofrequency ablation is a long, thin catheter that passes through a person’s peripheral veins and into the heart. Treatment is achieved by eliminating the abnormal electrical activity in the heart that causes atrial fibrillation.
The treatment is performed by a specialist electrophysiologist in the cardiac catheterization laboratory, with the patient lying flat on an x-ray bed and the skin taped to the electrocardiographic recording electrodes, and the catheter is inserted through a puncture vein up to the heart. The vein of choice is usually a femoral, shoulder or jugular vein. Under X-ray guidance, the electrode is delivered through the vein to the right atrium. In the atrial septum between the right and left atria, the surgeon selects a relatively weak location for the puncture so that the catheter can be passed directly from the right atrium into the left atrium for manipulation. The atrial septal puncture hole, however, can heal and close naturally after the procedure.
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. One of the electrode tips can be heated and then used to ablate the abnormal myocardial tissue that causes atrial fibrillation episodes. This ablation produces coagulation of only a very small portion of the myocardial tissue, and the extent of its production is so small that some sensitive patients may still feel discomfort despite the minimal symptoms produced by the ablation, which can usually be eliminated intraoperatively with medication without adverse effects.
X. What is the success rate of radiofrequency ablation therapy for atrial fibrillation catheters?
At present, the success rate of atrial fibrillation ablation reaches 80-90% for paroxysmal atrial fibrillation, and 60-80% for persistent and chronic atrial fibrillation, and the success rate of re-ablation will be further improved. The earlier atrial fibrillation is detected and treated, the higher the success rate.