Therapeutic principles 1. Objectives: Finding and correcting triggers and causes, ventricular rate control or rhythm control (restoration of sinus rhythm), and prevention of thromboembolic complications. The strategy of ventricular rate control is to control the ventricular rate within a certain range by drugs, and the purpose of rhythm control is to restore and maintain sinus rhythm. Regardless of ventricular rate control or rhythm control, thromboembolic prevention strategies must be selected according to the risk stratification of stroke. 2. Selection of rhythm control and ventricular rate control Individualize rhythm control or ventricular rate control strategies according to the type and duration of AF, symptom severity, concomitant cardiovascular or/and other diseases, age, short- and long-term therapeutic goals, and choice of pharmacologic and nonpharmacologic therapy. Atrial fibrillation can undergo electrical and mechanical remodeling after a period of time and may become permanent; therefore, young symptomatic patients with atrial fibrillation with mild underlying cardiac lesions undergo rhythm control using antiarrhythmic drugs or nonpharmacologic therapies. When choosing a strategy for ventricular rate control, the future impact of permanent AF on the patient needs to be considered.AFFIRM et al. concluded that elderly patients with cardiac disease associated with persistent AF need not be considered for restoration of sinus rhythm if they are asymptomatic, and that cardiac function in patients with heart failure associated with AF will deteriorate progressively over time. Rhythm control is theoretically superior to ventricular rate control, but there is no clear evidence of a difference between the two in terms of stroke incidence and mortality, which may be related to the poor effectiveness of currently applied antiarrhythmic drugs. Ventricular rate control is recommended for the following patients with atrial fibrillation: 1, asymptomatic patients with atrial fibrillation who must be converted to sinus rhythm without any specific reason; 2, for patients whose atrial fibrillation has persisted for several years, it is difficult to maintain sinus rhythm, even after conversion to sinus rhythm; 3, for patients in whom the risk of conversion and maintenance of sinus rhythm with antiarrhythmic drugs outweighs the risk of atrial fibrillation per se; 4, for patients who are elderly (greater than 65 years of age) or who have organic cardiac For the elderly (greater than 65 years of age) or patients with organic cardiac disease (including coronary artery disease, mitral stenosis, and left atrial internal diameter greater than 55 mm) whose etiology has not been corrected, ventricular rate control is as effective as rhythm control. Ventricular rate control (1) Goals Ventricular rate at rest ranges from 60 to 80 beats per minute, and heart rate is maintained at 90 to 115 beats per minute with moderate exercise. Patients with good ventricular rate control at rest may have a heart rate that is too fast during exercise, resulting in restricted ventricular filling and myocardial ischemia; therefore, it is necessary to evaluate the change in heart rate during sub-extreme exercise or over a 24-hour period, especially in patients who are symptomatic during activity. (2) Drugs Antiarrhythmic drugs such as β-blockers, CCBs and digitalis that inhibit conduction within the AV node and prolong its duration of refractory period are recommended to slow the ventricular rate, relieve symptoms and improve hemodynamics. Rhythm control (1) Rhythm restoration method: according to the condition and duration of atrial fibrillation, choose drugs or electric shock restoration. Atrial fibrillation with faster ventricular rate, severe symptoms and hemodynamic instability (including those with transatrial bypass anterior transmitter) should be synchronized with electrical resuscitation as soon as possible. The starting energy is 100J, and higher energies can be used in case of failed resuscitation. Stabilized patients preferred drug resuscitation, ineffective electrical resuscitation. Electrical resuscitation is more effective than pharmacologic resuscitation, but there is no difference in the risk of thromboembolism or stroke. In the case of underlying causes such as hyperthyroidism, infection and electrolyte disorders, resuscitation is generally not indicated until the cause has been corrected. The risk of thromboembolism is increased in those who have atrial fibrillation lasting more than 48h, and prophylactic anticoagulation therapy is needed before resetting the rhythm. (2) Drugs: Drugs seem to be the most effective in 7d after the onset of atrial fibrillation, and those who have exceeded 7d seldom recover on their own, and the effect of drug recovery is poor. Propafenone, amiodarone, dofetilide and ibutilide can reset atrial fibrillation. For out-of-hospital resuscitation, evidence that the drug is safe and effective for in-hospital application is required. Larger single oral doses of propafenone (600 mg) may be given to those without abnormal sinus node and atrioventricular node function, bundle branch block, prolonged QT interval, Brugada syndrome, and organic heart disease. Amiodarone may be applied in those who do not require urgent reentry. The application of sotalol and digitalis drugs (which may be harmful when resetting atrial fibrillation) is not recommended. (3) Maintenance of sinus rhythm after resuscitation: The recurrent nature of successful resuscitation of atrial fibrillation requires the application of antiarrhythmic drugs to prevent its recurrence. Propafenone, moresizine, amiodarone, sotalol and dofetilide are commonly used. Efficacy, safety (organ toxicity and arrhythmogenic effects) and tolerability should be assessed prior to use.Class Ic drugs have a higher incidence of arrhythmogenic effects in patients with organic heart disease and should be avoided in the setting of myocardial ischemia, heart failure and significant ventricular hypertrophy. Antiarrhythmic drugs are not recommended in patients with abnormal sinus node and AV node function. Propafenone in the prevention of paroxysmal atrial fibrillation or atrial flutter can cause the atrioventricular node 1:1 downward transmission and lead to rapid ventricular rate in atrial flutter, in which case it can be combined with β blockers and non-dihydropyridine CCBs and so on. Application of anti-arrhythmic drugs still occasionally appear and mild symptoms of atrial fibrillation episodes are regarded as effective drug prevention. 3.Anti-coagulation therapy The high incidence of stroke and the “four lows” of anticoagulants (low awareness of warfarin anticoagulation, low rate of warfarin and aspirin anticoagulation, and low rate of INR monitoring and compliance rate of warfarin anticoagulation) are the characteristics of Chinese patients with atrial fibrillation.