Ventricular fibrillation is so terrible, will atrial fibrillation turn into ventricular fibrillation?

In "The heart stops, the ECG will have three manifestations, one that requires emergency defibrillation!" "It is said that one of the three changes in ecG when the heartbeat stops is ventricular fibrillation, and there is another problem.

Some readers have asked, will atrial fibrillation turn into ventricular fibrillation?

Yes! Atrial fibrillation (atrial fibrillation) and ventricular fibrillation (ventricular fibrillation) are all fibrillations, are in the heart, will it change?

This reminds me of a case many years ago.

Many years ago, when I first entered the cardiology major, I followed the director to participate in a pre-hospital rescue.

Saying that it is pre-hospital rescue actually asks us to do an appraisal. Because this is a patient with cardiac arrest and sudden death, if we really wait for us to leave from the west of Beijing and rush to the east to rescue, it will be too late. Patients were rescued by primary doctors, and we were sent as judges.

The patient is an elderly man in his 60s with a history of coronary heart disease.

At noon on this day, when I was eating, I suddenly had an "atrial fibrillation" and was accompanied by a rapid ventricular rate, and my heart was beating very fast. So I called the medical staff of the outpatient department.

After the doctor arrived, he did an electrocardiogram to determine that it was atrial fibrillation, and he injected a "sidilan" intravenously into the patient.

Sidilan belongs to the "digitalis" class of preparations, which can slow down the heart rate because it can inhibit the conduction of the atrioventricular nodes of the heart, which reduces the conduction of atrial fibrillation to the ventricles. In the early 1980s, there were no more anti-arrhythmic drugs, and when atrial fibrillation was used, sidilan was often used.

However, there is one condition of atrial fibrillation that cannot be used when sildira, that is, patients with pre-excitation syndrome cannot use it. Because patients with atrial fibrillation with pre-excitation syndrome use sidilan, it is possible to cause ventricular fibrillation due to atrial fibrillation. We will talk about this later.

After injecting sildiran for more than 20 minutes, the patient suffered a cardiac arrest and died suddenly after rescue was ineffective.

Therefore, a very important task for us to go to the clinic at that time was to see whether the on-site rescue of patients was compliant, and whether there was any misuse of sidiland with pre-excitation syndrome.

The result, of course, is negative. We looked at the patient's ECG at the time of onset and the ECG of previous examinations, and found no manifestations of pre-excitation syndrome. In this way, there was no mistake in the doctor who used siddhi at that time. Of course, the current atrial fibrillation attack has basically used Siddiland, which is a later story.

Let's talk about why patients with atrial fibrillation with pre-excitation syndrome can cause atrial fibrillation to convert into ventricular fibrillation if they are not properly administered.

★ First of all, what is pre-excitation syndrome?

In layman's terms, there is a part of the ventricular myocardium pre-excited, pre-excitation.

Our normal atrium-to-ventricular conduction passes through the "AV node" in the middle, with an AV junction area. This atrioventricular junction and junction area has a very important function, that is, to delay the conduction from the atrium to the ventricles to a certain extent.

Why this, of course, is to keep the heart working better. Because blood flow is from the atrium to the ventricles, the atrium contracts first, then the ventricles contract, so that the blood flow can be kept through smoothly. The time of this sequential contraction is controlled by the atrioventricular node. When the heart is beating fast, the time for atrial agitation to ventricular excitation is shorter, and when the heartbeat is slow, it is appropriately prolonged. But there is also a limit, there is a normal range of values.

Therefore, under normal circumstances, atrial fibrillation is atrial fibrillation, which will not all be transmitted to the ventricles, at most, the ventricular rate is faster, and there will be no ventricular fibrillation.

People with "pre-excitation" are different, and atrial fibrillation may turn into ventricular fibrillation.

Patients with "pre-excitation" have a part of their heart muscle that builds a path between the atrial ventricles, which is medically called a "bypass". This bypass crosses the normal atrioventricular conduction, which can transmit the message of ECG in advance, and the ventricular myocardium is excited in advance.

Usually, the bypass only excites a small part of the heart muscle, and the corresponding pattern changes can be seen on the ECG. However, some people's "pre-shock waves" do not always appear, they are sporadic, so they may not be detected.

The relationship between bypass pre-excitation and normal AV conduction is like the relationship between walking through checkpoints, toll booths and trails. Normal conduction is like passing through a checkpoint, it is necessary to delay some time, and the atrial fibrillation waves will be blocked at the junction of the atrioventricular and will not pass so much. Copying the trail is different, there is no tube, one after another slipped away.

Of course, under normal circumstances, the trail is not so easy to walk.

Special circumstances are hard to say. There are many cars to pass through, such as dense atrial fibrillation waves; the main road is blocked, and the conduction of the Atrium junction area is delayed; at this time, the path is open.

★ When pre-excitation is combined with atrial fibrillation, if certain drugs are used, the atrioventricular conduction is blocked, delayed, and the conduction of the bypass is accelerated, which may lead to the transmission of atrial fibrillation waves to the ventricles through the bypass. If 400 waves of atrial fibrillation are transmitted to the ventricles per minute, atrial fibrillation causes ventricular fibrillation.

Digitalis drugs that are usually used to slow heart rate or reverse atrial fibrillation, heteropresentation (verapamil), diltiazem, and β blockers in calcium antagonists are not available, and amiodarone (ethaniodarfurone, up to dragons) is also risky, that is, the commonly used arrhythmia (propafenone), and there are case reports of ventricular fibrillation caused by atrial fibrillation.

Especially some patients with pre-excitation who do not usually show it.

Therefore, when atrial fibrillation occurs in patients with pre-excitation, electrical cardioversion is preferred to change the heart rhythm.

Cardiac bypass for pre-excitation syndrome can be done with radiofrequency ablation or surgical severance.

(All rights reserved, may not be reproduced without my authorization!) ）