Ventricular fibrillation

Introduction Ventricular fibrillation (referred to as ventricular fibrillation) is one of the common causes of sudden cardiac arrest. The ventricle delivers continuous, rapid, and even excitement more than 240 times per minute, called ventricular flutter. If the excitement of ventricular release is rapid and irregular, it is called ventricular fibrillation (ventricular fibrillation). The frequency of ventricular fibrillation can be between 250 and 600 beats per minute. Early or ventricular tachycardia in AMI should be actively controlled, strict ECG monitoring, and first-aid preparations such as defibrillation to prevent room-throwing or ventricular fibrillation.

Cause

Epicardial layer and M layer of cardiomyocytes can sometimes be expressed as all or no repolarization forms, which can inhibit or disappear the plateau phase (2 phase) of the action potential, and the 3-phase rapid repolarization wave appears in advance. The pole can shorten the action potential time by 40% to 70%, causing the ST segment elevation of the corresponding part. The causes of ventricular fibrillation are both cardiogenic and non-cardiac. Common causes of cardiogenic ventricular fibrillation are coronary heart disease, especially acute myocardial ischemia; common causes of non-cardiac ventricular fibrillation are anesthesia and surgical accidents, severe electrolyte and acid-base imbalance, electric shock, drowning, and drug poisoning or allergies. Wait.

an examination

Related inspection

Pulse oxygen heart sound map

When the patient has room-throttle and ventricular fibrillation, the normal ventricular function is lost due to the loss of normal contractile capacity of the ventricular muscle, but only irregular and uncoordinated "peristalsis". Therefore, the use of a stethoscope can not hear the heart sound, and the heart can not feel the beat of the heart and the pulse can not be touched. At this point, the patient has developed fainting, convulsions, and coma. On the surface, it has entered the state of "death". If you do an electrocardiogram at this time, you can only trace a curve of flutter or tremor, and prove that the patient is still alive. However, due to the environment at the time and the state of the patient, it is not always possible to calmly trace the electrocardiogram. If there are conditions, a clear diagnosis of room flutter and ventricular fibrillation can be made based on the characteristics of the electrocardiogram.

Differential diagnosis

Atrial fibrillation:

Referred to as atrial fibrillation, it refers to the impulse of 350-600 irregularities per minute in the atrium. The muscle fibers in the atrium are extremely uncoordinated, which loses 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. Atrial fibrillation can be divided into paroxysmal and persistent (chronic).

Acute atrial fibrillation:

First-time atrial fibrillation and within 24 to 48 hours, called acute atrial fibrillation. Usually, the seizure can stop itself in a short time. The P wave disappears on the electrocardiogram, and is replaced by an f-wave with a frequency of 350-600 beats/min, a different shape, and an uneven interval. The distance between QRS groups is absolutely irregular.

Heart tremor:

It refers to a kind of subtle vibration touched by the root of the palm, which is similar to the cat's wheezing, so it is also called "cat asthma", which is one of the characteristics of organic heart disease. No matter where the tremor is found, it indicates that there is severe stenosis or arteriovenous shunt in the site, and the normal heart will not tremble. Therefore, the appearance of tremor has important clinical significance, and is more common in some congenital heart diseases and heart valve stenosis.

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