Chapter 281 Interference

This patient had three ECGs in total.

One was an ECG with a blood potassium level of 7.25mmol/l, one was an ECG after intravenous atropine, and the other was a single II lead ECG.

The patient was a 91-year-old female.

When the blood potassium level was 7.25mmol/l, the ECG showed a heart rate of only 37 beats/min, so the doctor on duty directly injected atropine intravenously.

These three pictures are really messy!

This is the first time Lu Chen has seen this type of ECG.

Especially the various forms of the so-called "p" in these three pictures, which makes people very confused and clueless. No wonder they are said to be unsolvable ECGs.

"Does this first ECG have a p wave?"

Someone asked in the group, and the originally noisy group suddenly became a little quiet.

After a while, a doctor from the cardiology department of the county hospital spoke weakly: "The first electrocardiogram has no P and no trace of reverse P. Isn't this sinoventricular conduction?"

What's even more strange is that the t wave in the first picture is indeed very symmetrical, not the typical high and sharp.

The second picture is after intravenous atropine injection, the t wave becomes very high and sharp, a typical hyperkalemic electrocardiogram: Eiffel Tower-like t and tent-like t.

This picture was taken not long after, without any potassium-lowering measures.

"No, I don't think it's sinoventricular conduction."

The first to raise objections was Comrade Lao Fan.

In theory, if the picture above is sinoventricular conduction block, then this second picture should also be sinoventricular conduction!

But the second picture has so many positive "p" and reverse "p", which is really strange!

"Director Fan, I know you have been studying electrocardiograms and electrophysiology recently. Can you tell us about it so that everyone can learn from it."

A doctor in the group suddenly proposed.

Most of them knew that Fan Zhiping participated in the ECG competition and entered the second round.

Many people who are familiar with Fan Zhiping could not believe this result.

Originally, everyone's level was the same, and they were all mediocre. Why did Comrade Fan suddenly explode?

Therefore, some people asked Fan Zhiping to answer, and most of them were in a funny mood.

Especially the doctor who posted this picture. He has asked many people, even some directors of Jinghua First Hospital, and they have no definite answer. Can you, Fan Zhiping, do it?

But at this time, Lu Chen was about to speak in the group, but saw that Fan Zhiping sent a very long message.

"We know that the level of hyperkalemia in sinoventricular conduction is quite serious."

"Generally, there will be widening of the QRS wave, and the S wave of lead I will be very wide. You can also pay attention to the wide S wave of lead I in the ECG of patients with sinoventricular conduction."

"But this patient's ECG QRS wave is not widened, only 100ms, and there is no S wave in lead I. The blood potassium is 7.25mmol/l, which is not particularly high, not reaching 8.5mmol/l or above. So there are many doubts about the diagnosis of sinoventricular block in the first picture above."

After reading the information sent by Fan Zhiping, Lu Chen was quite surprised.

Comrade Fan's image judgment level has made great progress!

He is right, this first picture is not sinoventricular conduction.

At this time, Fan Zhiping continued to speak: "The first picture should be a junctional escape rhythm. Because there is a very fixed reverse P after each QRS wave group."

"From the overall macro analysis, the first picture is still very clear that it is a junctional escape rhythm. After amplifying the ECG gain by 2 times, it can be seen that V1 and V2 have obvious reverse P, which is negative first and then positive in both directions."

"Then that picture may also be a junctional escape rhythm, not sinoventricular conduction. As for why the reverse P disappeared, is it because the atrioventricular node function improved after using atropine, the conduction was accelerated, and the reverse P was buried in the QRS wave? I can't think of other more reasonable explanations for the time being."

"Hyperkalemia inhibits the sinoatrial node, sinus arrest occurs, and the possibility of junctional escape rhythm occurs."

Comrade Lao Fan's speech finally ended, but the WeChat group exploded again!

Everyone saw Fan Zhiping's explanation.

The first time, I didn't understand it very well.

I read it carefully the second time and got a clue.

I read it the third time and finally understood what he meant.

At this time, many people were surprised. How could Fan Zhiping's ECG level suddenly improve so quickly?

The most important thing is that he did not simply "talk about the picture", but deeply analyzed the ECG from the principle level of the ECG.

"I think what Lao Fan said makes sense!"

"Well, if you look at it this way, sinoventricular conduction is ruled out!"

"I support Director Fan's diagnosis!"

After Fan Zhiping gave his reasons, many doctors in the WeChat group supported the diagnosis of junctional escape rhythm.

Lu Chen thought about it and replied: "I also support Director Fan!"

Lu Chen's speech put the final nail in the coffin of Fan Zhiping's diagnosis.

Seeing that "Professor Lu" agreed with Lao Fan's speech, everyone in the group basically acquiesced to the diagnosis of the first picture.

At this time, the doctor who sent this picture asked again: "Teachers, the diagnosis of the first picture is clear, then the second picture, after the patient was injected with atropine intravenously, what is this ECG?"

After this, everyone was silent again.

In this second electrocardiogram, various positive "p"s and reverse "p"s are very complicated and confusing.

At the first time, Lu Chen was unable to interpret this picture.

If we simply look at the II lead, this picture looks like a third-degree atrioventricular block or interference atrioventricular dissociation.

As expected, a doctor in the group immediately said, "Is the second picture a third-degree atrioventricular block?"

Lu Chen stared at the second ECG closely and shook his head slightly.

If it is a third-degree atrioventricular block or a high-degree atrioventricular block, why can the QRS wave after the reverse P always be transmitted?

Obviously, atrioventricular block cannot explain it!

Whether it is atrioventricular block or interference atrioventricular dissociation, or atrioventricular block combined with interference atrioventricular dissociation, it cannot explain this second ECG!

Everyone in the group talked about it, and everyone said that in addition to their own opinions, they also gave their own reasons.

But no one could convince anyone!

Lu Chen looked at the second picture carefully and his head was big!

The "p" and reverse "p" in this picture appeared repeatedly, UU reading wwｗ． uukanshu． net can't even see any pattern.

You know, the first step in interpreting an electrocardiogram is to look at the p wave of the electrocardiogram.

But now there is a problem in the first step of interpreting the image!

Lu Chen took a deep breath and calmed himself down.

After this period of high-intensity electrocardiogram and electrophysiological training, although Lu Chen has made a lot of progress, the knowledge content is very complicated.

It is quite difficult for Lu Chen to mobilize all the knowledge points at the first time.

After calming himself down for a few minutes, Lu Chen began to think about this second electrocardiogram again.

Suddenly, an idea flashed through Lu Chen's mind.

"These so-called positive "p" and reverse "p" may be interference?"

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