1, paroxysmal atrial fibrillation: in atrial fibrillation episodes, you can choose drugs that slow down the ventricular rate, but also drugs that reset the rhythm. For those who have frequent attacks, atrial resetting drugs should be used in the intervals between attacks, instead of drugs that slow down the ventricular rate. In isolated atrial fibrillation and non-coronary atrial fibrillation with hypertension or left ventricular hypertrophy, propafenone or morethizine is preferred, or if ineffective, sotalol, followed by amiodarone. In coronary artery disease and post-myocardial infarction atrial fibrillation, IC-type drugs are not used. If the patient is young and has good cardiac function, sotalol can be chosen; if the patient is old and has poor cardiac function, amiodarone is chosen; for paroxysmal AF in chronic congestive heart failure, amiodarone is chosen. 2, persistent atrial fibrillation: its therapeutic countermeasures include: (1) resetting the rhythm and long-term application of antiarrhythmic drugs to prevent recurrence. (2) slowing down the ventricular rate and anticoagulation. If you choose the countermeasure ① you should consider the drug used for atrial resetting, and the principle of drug selection is the same as paroxysmal atrial fibrillation; if you choose the countermeasure ② you should choose the drug that slows down the ventricular rate. 3. Permanent atrial fibrillation: It is a type of atrial fibrillation where it is impossible to restore sinus rhythm, and drugs that slow down the ventricular rate and anticoagulants should be used for treatment. (1) digitalis drugs, slowing down the ventricular rate while having a positive inotropic effect, can be used in patients with atrial fibrillation with cardiac insufficiency. Because the mechanism of ventricular rate slowing by digitalis drugs is through excitation of the vagus nerve, indirectly acting on the atrioventricular node, prolonging its expiration period and increasing occult conduction, so digitalis drugs can satisfactorily control the ventricular rate of atrial fibrillation during sleep and rest. In the case of sympathetic nerve dominance during activity or in critical emergencies such as pulmonary heart disease, asthma, acute left heart failure and perioperative period, sympathetic excitation is limited, and digitalis drugs have limited efficacy. (2) β-blockers, which antagonize sympathetic nerve activity. Non-dihydropyridine calcium antagonists slow down atrioventricular conduction and ventricular rate by blocking calcium channels, which can effectively control ventricular rate not only in sleep or resting state, but also in atrial fibrillation during exercise. In the case of these critical emergencies, intravenous diltiazem can be used when drugs such as trichothecenes are ineffective. In addition, atrial fibrillation combined with pre-excitation syndrome, digitalis, non-dihydropyridine calcium antagonists, and beta-blockers are not used. Drugs that prolong the atrioventricular collateral tract inactivity should be used (e.g., intravenous procainamide, propafenone, or amiodarone).