Chronic atrial fibrillation

Introduction Atrial fibrillation, referred to as atrial fibrillation, refers to the generation of irregular impulses of 350-600 beats per minute in the atria. The muscle fibers in the atrium are extremely uncoordinated and tremble, thus losing effective contraction. It is also one of the most common arrhythmias in middle-aged and elderly people. Because of the physiological block in the atrioventricular junction, the ventricular rate is significantly lower than the atrial rate, generally 90 to 150 beats / min, rarely more than 170 beats / min.

Cause

The onset of atrial fibrillation is paroxysmal or persistent. Paroxysmal atrial fibrillation can be seen in normal people, when emotional, postoperative, exercise or acute alcoholism occurs. Patients with heart and lung disease develop acute hypoxia, hypercapnia, metabolic disorders or hemodynamic disorders. Atrial fibrillation can also occur. Persistent atrial fibrillation occurs in patients with pre-existing cardiovascular disease, common in rheumatic valvular heart disease, coronary heart disease, hypertensive heart disease, hyperthyroidism, constrictive pericarditis, cardiomyopathy, infective heart Endometritis, heart failure, and chronic pulmonary heart disease. Atrial fibrillation occurs in patients with no known heart disease, known as isolated atrial fibrillation.

an examination

Related inspection

ECG dynamic electrocardiogram (Holter monitoring)

Early atrial fibrillation was divided into paroxysmal atrial fibrillation and chronic atrial fibrillation, because in the absence of effective antiarrhythmic drugs and cardioversion, paroxysmal atrial fibrillation refers to atrial fibrillation that can be self-retrodial, and not Self-reported is called chronic atrial fibrillation.

It is currently considered that the possibility of spontaneous cardioversion of atrial fibrillation lasting more than 7 days is very small, called chronic atrial fibrillation.

The first episode of atrial fibrillation is within 24 to 48 hours and is called acute atrial fibrillation.

Chronic atrial fibrillation can be divided into paroxysmal, persistent, and permanent depending on the duration of occurrence, which is different from international classification.

The initial atrial fibrillation in the international classification does not emphasize whether it is self-recyclable and its duration, so it can also be continuous or permanent.

Chronic atrial fibrillation refers to persistent or permanent atrial fibrillation, excluding paroxysmal atrial fibrillation. The symptoms of atrial fibrillation are mainly as follows:

First, the symptoms of paroxysmal atrial fibrillation are characterized by a sudden onset of the attack, the patient feels guilty, shortness of breath, discomfort in the precordial area and anxiety. In elderly people with coronary heart disease, the ventricular rate is very high at the beginning of atrial fibrillation, and there may be dizziness and even syncope. Sometimes heart failure and shock may occur. The duration of each episode varies, and the short is only a few seconds, which can occur frequently. The elderly can last for several days to several weeks.

Second, persistent atrial fibrillation symptoms are related to the original heart disease and ventricular rate. The symptoms of this type of atrial fibrillation are mainly: atrial fibrillation patients feel guilty, shortness of breath, especially after the activity, the ventricular rate is significantly increased. People with persistent atrial fibrillation are prone to heart failure. In atrial fibrillation, there is no contraction force in the atria, hemodynamic disorder, prone to wall thrombosis, leading to embolism of the body and lungs, and cerebral embolism and limb arterial embolism are more common.

Third, if there is no other heart disease, and the heartbeat is normal during atrial fibrillation, the patient may not have any symptoms of atrial fibrillation. It is discovered by chance. If the atrial fibrillation causes a rapid heartbeat, the patient may have palpitation, shortness of breath, chest tightness, Hemorrhoids, panic, etc., if there are other heart diseases, it will aggravate the symptoms of heart disease, especially heart failure.

Fourth, the symptoms of atrial fibrillation are also affected by the sensitivity and tolerance of the patient's perceived symptoms. Some patients may have obvious symptoms when they have atrial fibrillation. With the prolongation of the disease course, some patients may gradually adapt to the symptoms. May reduce or even disappear.

Differential diagnosis

When atrial flutter and atrial fibrillation combined with indoor conduction block or impulse along the pre-excitation syndrome, the ventricular tachycardia and ventricular fibrillation should be compared.

(1) Atrial flutter should be differentiated from other rules of tachycardia: atrial flutter with a ventricular rate of 150 beats/min should be differentiated from sinus tachycardia and supraventricular tachycardia. Careful search for the waveform of atrial activity, and its relationship with the QRS complex, supplemented by measures to slow the conduction of the atrioventricular to expose the flutter wave, is not difficult to identify. Atrial flutter and atrial rate of 250 beats/min and atrial tachycardia with 2:1 atrioventricular block are sometimes difficult to identify.

(B) atrial fibrillation should be differentiated from other irregular arrhythmias: such as frequent premature beats, supraventricular tachycardia or atrial flutter accompanied by irregular atrioventricular block. An electrocardiogram can make a diagnosis. When atrial fibrillation is accompanied by complete bundle branch block or pre-excitation syndrome, the electrocardiogram appears to resemble ventricular tachycardia. Careful identification of atrial fibrillation, as well as significant irregularities in RR spacing, is conducive to the diagnosis of atrial fibrillation.

(C) the identification of atrial fibrillation with frequency-dependent intraventricular conduction changes and ventricular ectopic beats: individual QRS complex malformations are sometimes difficult to identify. The following points are useful for the diagnosis of ventricular ectopic beats: the malformed QRS complex has a fixed pairing distance from the previous heartbeat, followed by a longer interval; V1 single-phase or biphasic QRS (non-rSR' type) Wave group, V5S or rS type QRS complex. The following points are useful for the diagnosis of frequency-dependent intraventricular conduction changes: the ventricular rate is fast, the malformed QRS complex has no fixed distance from the previous heartbeat, and most of them are the first early QRS wave after a longer RR interval. Groups, followed by no long pauses; V1rSR' type QRS complexes, small Q waves in V6; different degrees of QRS complex broadening can be seen on the same lead.

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