I can see health

Chapter 285 Interference
This patient has a total of three ECGs.

One is the electrocardiogram of serum potassium 7.25mmol/L, one is the electrocardiogram after intravenous atropine, and the other is a separate lead II electrocardiogram.

The patient is a 91-year-old female.

When the blood potassium was 7.25mmol/L, the electrocardiogram showed that the heart rate was only 37 beats/min, so the doctor on duty directly injected atropine intravenously.

These three pictures are really messed up!

It was the first time that Lu Chen saw this kind of ECG.

In particular, the so-called "P" in various forms in these three pictures makes people very confused and clueless. No wonder it is said to be an unsolvable electrocardiogram.

"Does this first ECG have a P wave?"

I don't know who asked a question in the group, the originally noisy group suddenly became a little quiet.

After a long while, a doctor from the Cardiology Department of the county hospital spoke weakly: "The first ECG, there is no P, and there is no trace of reverse P. Isn't this sinoventricular conduction?"

And what's even more strange is that the T wave in the first picture is indeed very symmetrical, not the typical high peak.

The second picture is after static administration of atropine, the T wave becomes very sharp, typical hyperkalemia ECG: Eiffel Tower-like T and tent-like T.

This picture was taken not long after, without any measures to lower blood potassium.

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

Comrade Lao Fan was the first to raise objections.

Logically speaking, if the picture above shows sinoventricular block, then the second picture should also be sinoventricular conduction!

But in the second picture, there are so many positive "P" and reverse "P", which is really strange!
"Director Fan, I know that you have been studying electrocardiograms and electrophysiology recently. Come and tell us, so that everyone can come and learn."

A doctor suddenly suggested in the group.

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

Many people who are familiar with Fan Zhiping can't believe this result.

Originally, everyone's level was the same, the same mediocre, why did Comrade Lao Fan suddenly exploded?
Therefore, some people asked Fan Zhiping to answer, mostly with the attitude of watching a joke.

Especially the doctor who posted this picture, he has already asked many people, even some directors of Jinghua No. [-] Hospital, they have no definite answer, can you, Fan Zhiping, do it?

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

"We know that the level of sinoventricular hyperkalemia is more serious."

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

"However, the QRS wave of this patient's electrocardiogram did not widen, it was only 100ms, and there was no S wave in lead I, and the blood potassium was 7.25mmol/L, which was not particularly high, and did not reach more than 8.5mmol/L. So the first one above There are many doubts about the diagnosis of sinoventricular block in this picture."

After reading the message from Fan Zhiping, Lu Chen was quite surprised.

Comrade Lao Fan's level of judging pictures has made great progress!

He was quite 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 inverse P after each QRS complex."

"Analyzing from the overall macroscopic perspective, the first picture is still clearly a junctional escape rhythm. After amplifying the gain of the electrocardiogram by 2 times, it can be seen that V1 and V2 have obvious reverse P, and the two directions are negative first and then positive."

"Then that picture may also be a junctional escape rhythm, not sinoventricular conduction. As for why the reverse P disappeared, is it possible that the function of the atrioventricular node improved after atropine was used, and the conduction accelerated, and the reverse P was buried in the QRS wave. , I can't think of any other more reasonable explanation at the moment."

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

Comrade Lao Fan's speech finally came to an end, but the WeChat group exploded again!

Everyone saw Fan Zhiping's explanation.

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

After reading it carefully for the second time, I got a clue.

After reading it a third time, I finally understood what he meant.

At this time, many people were surprised, why did Fan Zhiping's ECG level suddenly rise so fast?
The most important thing is that he did not simply "look at the picture and talk", but deeply analyzed the electrocardiogram from the principle level of the electrocardiogram.

"I think what Old Fan said makes sense!"

"Well, looking at it this way, sinus conduction has been ruled out!"

"I support Director Fan's diagnosis!"

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

Lu Chen thought for a while and replied, "I also support Director Fan!"

Lu Chen's speech sealed Fan Zhiping's diagnosis.

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

At this time, the doctor who sent this picture asked again: "Masters, the first picture is a clear diagnosis, and the second picture, after the patient has been injected with atropine, what is this electrocardiogram?"

As soon as these words came out, everyone was silent for a while.

In the second electrocardiogram, various positive "P" and reverse "P" are very complicated and confusing.

At the first moment, Lu Chen couldn't read the picture.

If you look at lead II in this way, it looks like a third-degree atrioventricular block or interfering atrioventricular separation.

Sure enough, a doctor immediately asked in the group, "Is the second picture a third-degree atrioventricular block?"

Lu Chen stared at the second ECG, then shook his head slightly.

If it is third-degree atrioventricular block or high-grade atrioventricular block, why can the QRS wave behind the inverse P always be conducted?

Apparently atrioventricular block doesn't explain it!

Neither AV block nor interfering AV dissociation, nor AV block combined with interfering AV dissociation, can explain this second ECG!

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

But no one can convince anyone!
Lu Chen carefully looked at the second picture, and his head grew bigger!

The "P" and inverse "P" in this picture appear repeatedly, and there is no regularity.

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

But now there is a problem in the first step of judging the picture!

Lu Chen took a deep breath to calm himself down.

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

It is very difficult for Lu Chen to mobilize all the knowledge points in the first place.

After calming himself down for a few minutes, Lu Chen started thinking about the second ECG again.

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

"These so-called looks like positive "P" and reverse "P". Could it be the possibility of interference?"

(End of this chapter)