What Are the Different Causes of Atrial Fibrillation?

Atrial fibrillation (AF) is the most common persistent arrhythmia. With increasing age, the incidence of atrial fibrillation continues to increase, reaching 10% in people over 75 years of age. During atrial fibrillation, the frequency of atrial agitation is 300 to 600 beats per minute. The heartbeat frequency is often fast and irregular, sometimes up to 100 to 160 beats per minute. Not only is the heartbeat much faster than normal people, but it is definitely not uniform, and the atria are lost Effective contractile function. The prevalence of atrial fibrillation is also closely related to diseases such as coronary heart disease, hypertension and heart failure.

Basic Information

nickname: Atrial fibrillation
English alias: atrial fibrillation, AF
Visiting department: Cardiology

Multiple groups: Seniors
Common causes: Rheumatic heart disease, coronary heart disease, hyperthyroidism, etc.
Common symptoms: Palpitations, fatigue, fatigue; dizziness; chest discomfort; shortness of breath, etc.

Causes of AF

Common causes of AF include hypertension, coronary heart disease, cardiac surgery, valvular disease, heart failure, cardiomyopathy, congenital heart disease, pulmonary embolism, hyperthyroidism, etc., and drinking, mental stress, water and electrolyte disorders, Severe infection, etc .; In addition, it can be combined with other types of arrhythmia.

AF classification

There is no unified classification of AF, and it can be divided into paroxysmal AF, persistent AF, and permanent AF according to the duration. It is generally believed that paroxysmal atrial fibrillation refers to those who can revert to sinus rhythm on their own within 7 days, and generally last less than 48 hours; persistent atrial fibrillation refers to those who need more than 7 days and require medication or electric shock to revert to sinus rhythm. ; Permanent atrial fibrillation refers to those who cannot be converted to sinus rhythm or relapse within 24 hours after conversion.

According to the presence or absence of basic heart disease, it is divided into pathological atrial fibrillation and idiopathic atrial fibrillation (no basic heart disease in clinical examination). Idiopathic atrial fibrillation often occurs in younger people, most of whom are less than 50 years old. Idiopathic atrial fibrillation is sometimes called solitary atrial fibrillation.

Clinical manifestations of AF

Palpitations

Feel a rapid heartbeat with fatigue or tiredness;

Dizziness

Dizziness or even fainting;

3. Chest discomfort

Pain, pressure or discomfort in the anterior region of the heart;

4. Shortness of breath

Feeling difficult to breathe during light physical activity or rest, some patients may not have any symptoms.

During atrial fibrillation, the atrium loses its contractile function, and the blood is easily stagnated in the atrium to form a thrombus. After the thrombus falls off, it can follow the blood to the whole body, causing cerebral embolism (stroke), limb arterial embolism (even severe amputation). High risk factors for stroke in patients with AF include previous history of embolism, hypertension, diabetes, coronary heart disease, heart failure, left atrial enlargement, and so on.

Atrial fibrillation

Atrial fibrillation can be preliminarily diagnosed based on clinical symptoms and signs, but ECG examination is needed to confirm the diagnosis. For patients who have difficulty capturing transient episodes of AF, dynamic electrocardiogram and other examinations are required.

AF treatment

Treatment principle

(1) Restore sinus rhythm Only the restoration of sinus rhythm (normal heart rhythm) can achieve the purpose of complete treatment of AF, so any patient with AF should try to restore sinus rhythm.

(2) Control of rapid ventricular rate For patients with atrial fibrillation who cannot restore sinus rhythm, drugs can be used to slow down the faster ventricular rate.

(3) Prevent thrombosis and stroke If sinus rhythm cannot be restored during atrial fibrillation, anticoagulant drugs can be applied to prevent the occurrence of thrombosis and stroke.

For some diseases such as hyperthyroidism, acute alcoholism, and atrial fibrillation caused by drugs, AF may disappear on its own after the cause has been eliminated.

2. Drug treatment

At present, drug therapy is still an important method for treating AF. Drugs can restore and maintain sinus rhythm, control ventricular rate, and prevent complications of thromboembolism.

Sinus reversal (normal rhythm) drugs: For new-onset AF, the proportion of spontaneous sinus recovery within 48 hours is high (about 60% within 24 hours), which can be observed first, or propafenone or The method of taking flucarbam. Those with atrial fibrillation that have lasted longer than 48 hours and less than 7 days. Flukamin, dofetilide, propafenone, ibritide, and amiodarone can be used for intravenous drug conversion. The success rate can reach 50%. . The onset of atrial fibrillation lasts for more than a week (persistent atrial fibrillation). The effect of drug conversion is greatly reduced. The commonly used and proven drugs are amiodarone, ibritide, and dofetilide.

Drugs that control ventricular rate (frequency control): Control of ventricular rate can ensure basic heart function and minimize cardiac dysfunction caused by atrial fibrillation. Common drugs include:

(1) -blockers are the most effective, commonly used and often alone drugs;

(2) Calcium channel antagonists such as verapamil and diltiazem can also be effectively used for ventricular rate control during atrial fibrillation, especially for exercise-controlled ventricular rate better than digoxin, and the combined effect of digoxin It is also better than using alone. Especially for patients without organic heart disease or normal left ventricular systolic function and with chronic obstructive pulmonary disease;

(3) Digitalis is a first-line medication for controlling ventricular rate of atrial fibrillation in emergency situations. At present, it is mostly used clinically for ventricular rate control with left heart failure;

(4) Amiodarone can reduce ventricular rate during atrial fibrillation. It is not recommended for long-term ventricular rate control during chronic atrial fibrillation, but only when other medications are ineffective or contraindicated, emergency control of ventricular rate is needed in patients with AF and heart failure The combination of amiodarone and digitalis is preferred.

(5) Anticoagulation therapy is a necessary means to prevent thrombosis and embolism in patients with AF. Patients with AF should be treated with anticoagulation if they have the following conditions: age 65 years; previous history of stroke or transient ischemic attack Congestive heart failure; hypertension; diabetes; coronary heart disease; left atrium enlargement; left atrial thrombus detected by echocardiography. Anticoagulation treatment must be under the guidance of a specialist. Excessive anticoagulation may cause bleeding, and insufficient anticoagulation does not have a preventive effect.

3. Non-drug treatment

Non-drug therapies for AF include electrocardioversion (reversion to sinus rhythm), radiofrequency ablation, and surgical maze surgery (complete cure of AF).

(1 ) Electrical cardioversion refers to a method of restoring sinus rhythm by placing two electrode pads on an appropriate part of a patient's chest and issuing a current through a defibrillator. Electric cardioversion is suitable for: emergency atrial fibrillation (such as myocardial infarction, extremely fast heart rate, low blood pressure, angina pectoris, heart failure, etc.), the symptoms of atrial fibrillation are severe, and the patient cannot bear it. Maintained and recurrent atrial fibrillation. Electrical cardioversion is not a cure for AF. Patients with AF often relapse, and some patients need to continue taking antiarrhythmic drugs to maintain sinus rhythm.

(2 ) Catheter ablation is applicable to the majority of patients with atrial fibrillation, with minimal trauma and easy patient acceptance.

(3 ) Surgical maze surgery is currently mainly used for patients with AF who need cardiac surgery for other heart diseases. The operation is effective, but the trauma is large.

AF prognosis

Stroke is one of the greatest harms of AF. The incidence of stroke in nonvalvular AF patients is 5.6 times that of normal people, and the incidence of stroke in valvular AF is 17.6 times that of normal people. The consequences of stroke are more severe.

AF prevention

Precautions in the lives of patients with AF include: quit smoking, limit alcohol consumption, and some patients may need to avoid caffeine-containing substances such as tea, coffee, cola, and some over-the-counter medications. Be careful with certain medications for cough or cold.