What Is Cardiac Fibrillation?

Atrial fibrillation (AF) is one of the most common arrhythmias. It is an atrial rhythm with a disordered agitation and ineffective contraction of the atrium. It is an arrhythmia disorder caused by many small reentry loops caused by the atrial-dominant reentry loop. Is very common. It can be seen in all patients with organic heart disease, atrial fibrillation can also occur in patients with non-organic heart disease, high incidence and long duration, and can cause serious complications such as heart failure and arterial embolism. Causes patients with disabilities or increased mortality.

Basic Information

nickname

Atrial fibrillation

English alias

atrial fibrillation, Af

Visiting department

Cardiology

Multiple groups

Seniors

Common causes

Organic heart disease

Contagious

no

Causes of atrial fibrillation

Rheumatic heart valve disease

Rheumatic heart valve disease is still the most common cause of atrial fibrillation, especially in mitral stenosis with insufficiency. Among patients with mitral stenosis, atrial fibrillation is 41%, and atrial fibrillation is less likely to occur in aortic valve disease.

Coronary heart disease

With the increasing incidence of coronary heart disease, coronary heart disease has become the leading cause of AF in many countries and regions.

3. Cardiomyopathy

Atrial fibrillation can occur in various types of cardiomyopathy, and the incidence is between 10% and 50%. It is more common in adults and can also occur in children. Primary congestive cardiomyopathy is the main type, accounting for about 20%.

4. Hypertension

The rate of hypertension in the causes of atrial fibrillation ranges from 9.3% to 22.6%. The occurrence of atrial fibrillation is related to the electrophysiological abnormalities of hypertrophic myocardium caused by hypertension, hypertrophic myocardial ischemia and hypertrophic myocardial fibrosis.

5. Constrictive pericarditis

The incidence of general patients is 22% to 36%, the incidence of atrial fibrillation in elderly patients can reach 70%, and patients with pericardial effusion can also be associated with atrial fibrillation.

6. Cor Pulmonale

Atrial fibrillation in pulmonary heart disease has been reported. The cause is related to repeated infections in the lungs, chronic hypoxia, acidosis, and electrolyte disturbances.

7. Congenital Heart Disease

In congenital heart disease, atrial fibrillation is mainly seen in patients with atrial septal defect.

8. Sick sinus node syndrome

When sinus bradycardia occurs, the ectopic excitability of the atrium is increased, which is prone to atrial fibrillation.

9. Pre-excitation syndrome

The main complication of pre-excitation syndrome is paroxysmal atrioventricular reentrant tachycardia, followed by atrial fibrillation. The incidence of atrial fibrillation of ventricular pre-excitation is generally considered to be related to age, which rarely occurs in children. The incidence of tremor is high.

10. Hyperthyroidism

Atrial fibrillation is one of the main symptoms of hyperthyroidism. The incidence of atrial fibrillation in patients with hyperthyroidism is 15% to 20%. Older patients with hyperthyroidism may have organic damage to the myocardium and prone to chronic atrial fibrillation.

Atrial fibrillation clinical manifestations

Symptoms

When atrial fibrillation occurs, in addition to hemodynamic changes caused by basic heart disease, atrial fibrillation causes atrial contraction loss, ventricular contraction becomes irregular, and ventricular rate increases. The most common symptom of patients is palpitations. If combined with coronary heart disease, patients may develop angina pectoris, dizziness, syncope, and severe heart failure and shock. Such as rheumatic heart disease mitral valve stenosis, often induced acute pulmonary edema, accompanied by pulmonary hypertension can occur in hemoptysis.

In some cases of slow and moderate atrial fibrillation, the patient may be asymptomatic, especially in the elderly, often found during physical examination or electrocardiogram.

2. Signs

(1) Signs of original heart disease The signs of atrial fibrillation vary depending on the primary heart disease.

(2) Three major signs of atrial fibrillation The first heart sound of the apex varies in intensity, the heart rhythm is absolutely irregular, and the pulse is short.

(3) Embolism Signs Patients with atrial fibrillation may develop vascular embolism signs in the brain, lungs, and limbs. The incidence of embolism is related to age, atrial size, and underlying heart disease. The incidence of cerebral infarction in patients with AF is 5 times higher than that in the normal population.

Atrial fibrillation

Electrolyte disturbance

Hypokalemia and elevated calcium can induce atrial fibrillation. Atrial fibrillation can also occur with abnormal serum T ₃ and T ₄ .

2. Other auxiliary inspections

The basic characteristics of the atrial fibrillation electrocardiogram are: P waves disappear, replaced by f waves with different shapes and sizes, different amplitudes and spacings, and the frequency is between 350 and 600 times per minute, and the QRS waves are irregular and the rhythm is absolutely not. Qi. The f wave is usually clear in leads II, III, aVF, and V1, and the other leads are often unclear. The disappearance of normal P waves and the occurrence of fibrillation are the main diagnostic conditions of AF. According to the size of f wave on lead V ₁ can be divided into: coarse large atrial fibrillation, that is, f wave is greater than 1mm. Fine and small atrial fibrillation: f wave is less than 1mm. The frequency of coarse atrial fibrillation is low, while that of fine atrial fibrillation is high.

Atrial fibrillation diagnosis

Medical history

Palpitations can be paroxysmal or persistent, or only chest tightness and fatigue.

2. Signs

The heart rhythm is absolutely irregular, the heart sounds vary, and the pulse is short.

3. ECG

(1) P wave disappears and is replaced by f wave with different amplitude, morphology and rhythm; frequency of 350 ~ 600 times / min, f wave can be quite similar to impure atrial flutter; it can also be slender and difficult to identify.

(2) The RR spacing is absolutely irregular. Patients generally have pathological and physiological conduction abnormalities, and can sometimes coexist with other types of arrhythmias, such as pre-constriction, paroxysmal supraventricular or ventricular tachycardia, and various atrioventricular block. Atypical performance.

Atrial fibrillation treatment

Cause treatment

The treatment of the cause of atrial fibrillation is very important. Active treatment of primary heart disease can easily convert AF to sinus rhythm and maintain it for a long time after recovery. Even if the cause cannot be cured, the hemodynamic abnormalities can be relieved. Very important. In patients with atrial fibrillation caused by ischemic heart disease, hypertensive heart disease, cardiomyopathy, etc., when myocardial ischemia improves, heart failure is corrected, and blood pressure is well controlled, the chance of atrial fibrillation is increased, and the Time maintains sinus rhythm. In patients with rheumatic heart disease with mitral stenosis and atrial fibrillation, many patients can maintain sinus rhythm after cardioversion after surgery.

2. Drug treatment

These include cardioversion, ventricular rate control, and anticoagulation.

3. Radiofrequency ablation treatment

Radiofrequency ablation is mainly used in patients with paroxysmal atrial fibrillation who have ineffective antiarrhythmic drugs, or who have obvious symptoms, and patients with persistent atrial fibrillation, whose ventricular rate is difficult to control. The earliest use was atrioventricular node ablation, which caused permanent complete atrioventricular block, and then combined with pacing therapy to improve patient symptoms and hemodynamic effects. In recent years, some progress has been made in the development of radiofrequency ablation therapy, and the efficacy has gradually improved. It has become an important method for the treatment of AF.

4. Surgical treatment

It mainly includes the "corridor surgery" and "maze surgery" of the Hitch bundle dissection. At present, the "maze surgery" is commonly used in clinical practice. The main mechanism is to guide the atria to excite at the same time between a series of incisions to eliminate atrial fibrillation, that is, to interrupt the common reentry loop through a series of incisions, and establish a special conduction pathway to synchronize the electrical activity of the atria. This operation not only preserves the "corridor" of the sinoatrial node to the atrioventricular node, but also allows the impulsive energy of the sinoatrial node to be transmitted to the various atrial muscle tissues so that the atrial muscles can contract uniformly.

5. Anticoagulation therapy and prevention of embolism

Atrial fibrillation combined with thromboembolism, the annual incidence of elderly patients reaches 5%, the atrial loss of effective atrial contraction during atrial fibrillation, blood stasis in the atrium is conducive to the formation of thrombus. After the thrombus falls off, it can move with the bloodstream, causing embolism in different parts of the body. Therefore, it is very important to actively treat anticoagulation.

Atrial fibrillation prognosis

Patients with occasional brief episodes without obvious discomfort have a good prognosis and do not require treatment. Persistent atrial fibrillation has a fast heart rate and a poor heart base, such as those with AMI or concurrent refractory heart failure.

Atrial fibrillation prevention

Atrial fibrillation and atrial flutter mostly occur in coronary heart disease, hypertensive heart disease, pulmonary heart disease, hypokalemia, acute lung infection, or digitalis poisoning. Therefore, the cause should be investigated first and treated actively. Generally, atrial fibrillation or atrial flutter frequently occurs before the onset of atrial fibrillation or atrial flutter, and should be actively treated to prevent the development of atrial fibrillation or atrial flutter. For authors who repeatedly send frequently, they can explore appropriate antiarrhythmic drugs for long-term maintenance at the minimum dose to prevent recurrence.