Standardized pharmacological treatment of atrial fibrillation The Second Hospital of Chifeng City Shan De-hong Principle of atrial fibrillation formation The Second Hospital of Chifeng City Department of Cardiovascular Medicine Shan De-hong Overview (1) Atrial fibrillation (atrial fibrillation for short) is an atrial rhythm in which the atria show disordered excitation and disordered contraction, and is the most common clinical arrhythmia. The main clinical manifestations are palpitations, chest tightness and dizziness, especially the atrial thrombus caused, which multiplies the incidence of stroke and mortality in patients, and the incidence of stroke in such patients is around 18%. Because atrial fibrillation is common and serious, it is increasingly urgent for clinicians to standardize the treatment of atrial fibrillation. (2) Clinical signs of atrial fibrillation (1) Signs of atrial fibrillation itself: absolute rhythm irregularity, unequal heart sounds, and short pulse ★ Exceptions ◇ Heart rhythm is regular when atrial fibrillation is combined with complete atrioventricular block ◇ No short pulse when the average ventricular rate is slow (3) Signs of thromboembolism: corresponding signs appear when the embolism is in different parts of the body. ECG characteristics of atrial fibrillation 1) P waves in each lead disappear and are replaced by f waves with inconsistent shape and amplitude and irregular spacing. 2) In most cases, f waves are most clear in V1 and II, III and avF, and the frequency of f waves is generally between 350 and 600 beats/min. 3) RR spacing is absolutely irregular. The RR spacing is absolutely irregular and the ventricular rhythm is absolutely irregular. 4) The ventricular rate varies, with the majority being fast. 5) The QRS pattern is generally normal, unless intraventricular differential conduction occurs. Epidemiology of atrial fibrillation Classification of atrial fibrillation Classification of atrial fibrillation by time of occurrence v Paroxysmal atrial fibrillation: Atrial fibrillation occurs in short bursts, lasting for several minutes, usually less than 1 month, and can be self-reversed to sinus rhythm. v Persistent AF: AF that lasts more than 1 month, often months to years, and may be converted to sinus rhythm. v Permanent AF: AF that is chronic and persistent for years to decades and cannot be converted to sinus rhythm. v Primary AF: AF that occurs within 48 hours is called acute AF. about 60% of acute AF is automatically converted to sinus rhythm within 8 hours of onset. Treatment of atrial fibrillation Currently, in addition to treating the primary cause and other etiologies, there are 3 main strategies for the treatment of atrial fibrillation: control of the ventricular rate, conversion and maintenance of sinus rhythm, and prevention of embolic events. Non-pharmacological treatments DC electrical cardioversion, implantable atrial defibrillators, transcatheter ablation therapy, and surgical treatment. Pharmacological treatment of atrial fibrillation Pharmacological treatment is still the mainstay. The primary disease has been corrected or controlled l Post-operative wind heart disease l Other heart disease Ventricular rate is fast and difficult to control with drugs such as digitalis No infection or rheumatic activity No intracardiac thrombus Atrial fibrillation – drug resuscitation (3) Contraindications to resuscitation Slow ventricular rate (<60bpm) before drug administration Definite SSS or severe AVB lasting more than 1 year Significantly large heart (LA >50mm) Digitalis toxicity Atrial thrombus Atrial fibrillation-rhythm restoration (4) Commonly used restorative drugs: l Propafenone (Ic) l Amiodarone (Class III) l Ebride (Class III) In addition: Sotalol Atrial fibrillation-rhythm restoration-drugs (5) 1. Propafenone: Intravenous: 1.5~2.0mg/kg, 10~20min, repeat 1-2 times if necessary, total not more than 300mg/h. Tonics: For those with insignificant symptoms: 2. Amiodarone Oral: 0.2, tid×7d; 0.2, bid×7d Maintenance: 0.1~0.2/d. Intravenous: 3~5mg/kg,20min→1mg/min×6h→0.5mg/min×12~36h Atrial fibrillation-rhythm medication (7) With amiodarone The dose of VT/VT prevention (0.2-0.3/d) should be greater than the maintenance dose of atrial fibrillation (0.1-0.2/d). 3. It is important to distinguish between the normal effects of the drug and its toxic side effects. Atrial fibrillation resuscitation-drugs (9) Caution: 1. Monitor closely during the course of drug administration (arrest may occur during rhythm conversion) 2. How to choose the drug: Propafenone is preferred in the following cases l No organic heart disease l Hypertension without significant left ventricular hypertrophy and heart failure Atrial fibrillation resuscitation (11) Maintenance of sinus rhythm How to choose the drug: Sotalol is optional in the following cases l Young patients l Coronary heart disease l Hypertensive patients (COPD patients should not be used) Atrial fibrillation resuscitation (12) Maintenance of sinus rhythm How to choose the drug: Amiodarone is optional in the following cases l Heart failure combined with atrial fibrillation l Hypertension Combined with significant left ventricular hypertrophy l Coronary artery disease Atrial fibrillation resuscitation (13) When to stop the drug? Atrial fibrillation resuscitation (14) Evaluation of medications for conversion and maintenance of sinus rhythm Advantages l Improved quality of life l Prevention of complications due to atrial fibrillation Disadvantages l Poor conversion and prevention of atrial fibrillation recurrence l Many side effects of medications l No reduction in overall mortality Treatment of atrial fibrillation – control of ventricular rate (1) Control of ventricular rate is mainly used in the following situations: l Rapid ventricular rate in initial or paroxysmal atrial fibrillation l Maintenance of l Persistent or chronic atrial fibrillation with sinus rhythm failure l Asymptomatic elderly patients l Those without indications for cardioversion Range of ventricular rate control: Quiet: 60-80 bpm Active: 90-115 bpm Drug use for ventricular rate control β-blockers are the first-line agents for ventricular rate control in atrial fibrillation Ø Coronary heart disease Ø Heart failure Ø Fast ventricular rate during exercise (better than digoxin) Ø Combined with digoxin Combination is better than alone Calcium antagonists: verapamil. Diltiazem 1, preferred in patients with COPD, pulmonary heart disease 2, hypertension combined with atrial fibrillation 3, intravenous diltiazem in acute cases (safe, fast acting, better effect) Ø Digitalis preparations (non-first line) for patients with heart failure Can control ventricular rate at rest but ineffective in controlling ventricular rate during exercise Treatment of atrial fibrillation – control of ventricular rate (4) Advantages of controlling ventricular rate: most of them can significantly reduce symptoms compared to Disadvantages of ventricular rate control: Ventricular rate is irregular and many patients remain symptomatic Atrial fibrillation persists l Thrombosis/embolism l Impact on cardiac function Comparing restoration and ventricular rate control (1) – Is restoration better than ventricular rate control? Clinical Trials Comparing Rhythms and Ventricular Rate Control P1AF: Pharmacological Intervention in Atrial Fibrillation RACE the Race Control versus Electrical Cardioversion AFFIRM the Atrial Fibrillation Follow-Up Investigation of Rhythm Managemeng Comparing Rhythm Restoration and Ventricular Rate Control (7) – Is Rhythm Restoration Better Than Ventricular Rate Control? Results: The results of the current clinical trials do not show that atrial fibrillation is more effective than ventricular rate control The side effects of the rhythm-restoring drugs are significantly more than those of ventricular rate control Older patients with atrial fibrillation: predominantly ventricular rate control Younger patients: if indicated – try to restart the rhythm Conclusion Maintenance of sinus rhythm is an important determinant of survival or a marker of good prognosis The adverse effects of antiarrhythmic drugs counteract their beneficial effects in maintaining sinus rhythm. The search for safe and effective ways to maintain sinus rhythm is the way forward (The AFFIRM investigators: Circulation 2004;109;1509) Antithrombotic therapy in atrial fibrillation (1) Importance of antithrombotic therapy Atrial fibrillation with valvular disease Annual stroke rate 17 times higher than without valvular disease and atrial fibrillation Leading cause of death and disability in atrial fibrillation Risk stratification for ischemic embolism in NVAF High risk – previous history of ischemic stroke, TIA, or thromboembolism in body circulation; age ≥75 years with hypertension, diabetes mellitus, or vascular disease; Clinical evidence of heart valve disease, heart failure, or impaired left ventricular function Intermediate risk – age 65 to 75 years without risk factors; age <65 years with diabetes, hypertension, or vascular disease Low risk - age <65 years without intermediate risk or High-risk factors ACC/AHA/ESC guidelines for anticoagulation in atrial fibrillation The choice of anticoagulant should be individualized: assessment of the risk-benefit ratio High-risk patients: anticoagulation (INR2-3) Combination of aspirin and warfarin is not recommended Anticoagulation is not superior to warfarin alone, while the risk of bleeding is significantly increased Recommendations for anticoagulation in atrial fibrillation (ACC/AHA/ESC) /Clinical background: rheumatic heart disease High risk factors, age < 75 years High risk factors, age > 75 years Age < 60 years Isolated atrial fibrillation Patients with contraindications to warfarin therapy Treatment: Warfarin (INR 2.0 - 3.0) Warfarin (INR 2.0 - 3.0) Warfarin (INR 1.5 - 2.6) Aspirin 325 mg/day Aspirin 325 mg/day Current status of anticoagulation therapy in China At present, there is little anticoagulation therapy in China l Insufficient awareness l INR is not widespread Most use low-dose aspirin Future tasks l Publicize and popularize anticoagulation therapy Maintaining INR 2.0-2.5 may be more suitable for antithrombotic treatment of atrial fibrillation in the Chinese population (6) Risks of long-term anticoagulation therapy Risk: bleeding events l Bleeding increases significantly when INR >4 Risk factors for bleeding l Age >75 years l Combination of antiplatelet agents l Uncontrolled hypertension l Previous history of bleeding, anemia, etc. Management when severe bleeding occurs l Discontinuation of anticoagulants l Use of vitamin K l Importation of fresh plasma and prothrombin complex Mild bleeding (e.g., gingival or subcutaneous) need not be treated, but INR should be monitored closely and dose adjusted promptly Monitoring and follow-up of anticoagulant therapy Onset of action and time to peak l Warfarin initiation Time to peak l Warfarin starting dose 2~3mg/d, onset of action in 2~4d l Peak therapy in 5~7 days Monitoring time l Start: every other day until INR is within target range for 2 consecutive times l Then monitor 1-2 times a week for 1-2 weeks l After stabilization, check 1-2 times a month Dose increase/decrease each time: l INR3: reduce dose l Dose increase/decrease each time: generally 0.625mg/d or less Resetting Anticoagulation principles