Active learning discussion around ECG

Post residency PG 1: 53 M with diabetes for five years and developed vomiting 5 months back and detected renal failure and put on dialysis since then. This ECG was taken when he presented to us with tachypnea with respiratory rate of 38/minute following the morning dialysis. 

Post residency PG 1: For those who responded in PM this was the second ECG taken a few seconds later.

[17/07/20, 5:36:09 PM] UG Student 3: Good evening sir.

Did he have Arrest because of hyperkalemia ?

[17/07/20, 5:36:23 PM]UG Student 3 :And after the dialysis, it got corrected

[17/07/20, 8:00:54 PM] PG post residency 1: What arrest?

[17/07/20, 8:03:43 PM] UG Student 3: Sir in the initial ECG, he had a prolonged bradycardia

[17/07/20, 8:03:49 PM] UG Student 3: Initially.

[17/07/20, 8:12:51 PM] UG Student 3: Sir in the initial ECG, the QRS complexes look narrow but in the 2nd ECG, they look broad

[17/07/20, 8:13:05 PM] UG Student 3: And rhythm is irregular

[17/07/20, 8:28:32 PM] PG post residency 1: So what was that due to? What kind of arrest? 🤔

[17/07/20, 8:29:37 PM] PG post residency 1: Are the QRS broad or just the S waves?

[17/07/20, 8:29:53 PM] PG post residency 1: In both. Why?

[17/07/20, 8:30:01 PM] UG Student 3: Yes sir it’s just the S waves.

[17/07/20, 8:30:33 PM] PG post residency 1 :Yes but why in just those two complexes?

[17/07/20, 8:30:59 PM] UG Student 3: Maybe Due to the hyperkalemia sir

[17/07/20, 8:31:16 PM] UG Student 3: He has capped T waves which are characteristic of Hyperkalemia

[17/07/20, 8:31:52 PM] PG post residency 1: We are not discussing the etiology but just the morphology of the EcG

[17/07/20, 8:33:04 PM] UG Student 3: Okay sir. 

So I thought it could be Sick sinus syndrome.

[17/07/20, 8:33:11 PM] UG Student 3: Because of the initial ECG

[17/07/20, 8:34:44 PM] UG Student 3: Accessory pathways?

[17/07/20, 8:39:46 PM] PG post residency 1 :What features made you think of that?

[17/07/20, 11:02:39 PM] UG Student 3: Because there was bradycardia

[17/07/20, 11:04:04 PM] UG Student 3: In the initial ECG sir

[17/07/20, 11:37:00 PM] UG Student 3: Sinus bradycardia, sinus arrest  too sir.

[18/07/20, 6:42:35 AM] PG post residency 1 :👍

[18/07/20, 6:45:42 AM] PG post residency 1 :Excellent. Please share the above ECG and the entire conversations above as an active learning blog post and share the link

[18/07/20, 6:46:03 AM] PG post residency 1 :Accessory pathways only for two complexes?

[18/07/20, 8:16:40 AM] PG post residency 1 :Here's a recent Ecg active learning discussion by one of your batchmates 

https://virtualmedicalcases.blogspot.com/2020/07/ecg-active-learning-conversation-around.html?m=1

[18/07/20, 9:04:29 AM] UG Student 3: Yes sir I will do it.

[18/07/20, 9:11:46 AM] UG Student 3: Thank you sir. 😊

[18/07/20, 9:13:15 AM] UG Student 3: Sir I was thinking maybe it’s just a disturbance and they are not actually delta waves. Because there were none in the 1st ECG but in the 2nd one there are some. And they are only in the chest leads not in the limb leads sir.

So maybe it could be just a disturbance

[18/07/20, 9:22:28 AM] PG post residency 1 :So what is the electrical mechanism of production of delta waves? Accessory pathways are it's mechanical counterpart but what really happens at a electrophysiological level?

[18/07/20, 9:24:34 AM] PG post residency 1 :In our case it might be the 1 st one with hidden p waves

01.CIR.47.3.635.pdf

[18/07/20, 9:24:38 AM] PG post residency 1 :Now check and share if junctional rhythm is seen in sick sinus syndrome

[18/07/20, 9:31:06 AM] PG post residency 1 :What is sinus arrest?

[18/07/20, 9:31:09 AM] PG post residency 1 :SA node ceases for 3secs

[18/07/20, 9:31:10 AM] PG post residency 1 :How is it diagnosed in the EcG?

[18/07/20, 9:31:11 AM] PG post residency 1 :Impulse is not generated within less than 2 sec

[18/07/20, 9:31:11 AM] PG post residency 1 :How will it appear in ECG? Can you share a Google Image?

[18/07/20, 9:31:12 AM]PG post residency 1 :https://images.app.goo.gl/VW43qVuBg4vSZitN7

[18/07/20, 9:31:13 AM]PG post residency 1 :Do you think it's the same as our patient's Ecg?

[18/07/20, 9:31:14 AM]PG post residency 1 :Is there a sinus arrest sir?

[18/07/20, 9:35:57 AM]PG post residency 1 :P wave is absent before the qrs in lead 2

[18/07/20, 9:35:57 AM]PG post residency 1 :In our case

[18/07/20, 9:35:58 AM] PG post residency 1 :👍

So are their types of sinus arrests where that is possible? 

What is the origin of our QRS there if not the sinus? Can it be junctional?

[18/07/20, 9:35:58 AM]PG post residency 1 :Yes sir it can be junctional

[18/07/20, 9:35:59 AM]PG post residency 1 :Origin of qrs could be av node or ventricle

[18/07/20, 9:35:59 AM]PG post residency 1 :Search and share what are the characteristics of junctional complexes and see if that fits our Ecg

[18/07/20, 9:36:00 AM]PG post residency 1 :But what happened with min few secs that ecg is so different

[18/07/20, 9:36:00 AM]PG post residency 1 :Within*

[18/07/20, 9:36:01 AM] PG post residency 1 :In our case it might be the 1 st one with hidden p waves

[18/07/20, 9:36:02 AM]PG post residency 1 :Now check and share if junctional rhythm is seen in sick sinus syndrome

[18/07/20, 9:36:05 AM] PG post residency 1 :Tell me what is the most striking difference between our ECG and the one in Google Images. Maybe it would be better if you can select just one from Google Images and reshare

[18/07/20, 9:40:52 AM]PG post residency 1 :👆The entire conversation is jumbled up above. Sorry. 😅

Have asked the student to share it sequentially in an online log link

[18/07/20, 10:50:25 AM] UG Student 3: Yes sir. There is junctional rhythm.

[18/07/20, 11:00:24 AM] UG Student 3: Since there is an accessory pathway, the impulse conducts through that and the AV node thereby we get a slurred QRS complex first followed by a normal QRS complex

[18/07/20, 11:00:34 AM] UG Student 3: That slurring is the delta wave

[18/07/20, 11:08:57 AM] PG post residency 1 : Is it possible that an accessory pathway can develop briefly for a few beats in terms of electrophysiology? 

Hope you went through this https://medcases.blogspot.com/2020/07/ecg-active-learning-conversation.html?m=1 around the same patient

[18/07/20, 12:19:42 PM] UG Student 3: Yes sir I went through it.

[18/07/20, 12:27:24 PM] UG Student 3: Yes sir it is possible in the case of WPW syndrome.

[18/07/20, 12:28:37 PM] UG Student 3: Because there are two pathways with different refractory periods sir.

[18/07/20, 2:03:11 PM] PG post residency 1: I meant can it happen without a mechanical accessory bypass tract just as an electrical phenomenon due to hyperkalemia?

[18/07/20, 2:55:14 PM] UG Student 3: Yes sir it can happen

[18/07/20, 4:11:52 PM] PG post residency 1: Share some literature around that?

[18/07/20, 11:35:40 PM] UG Student 3: “As potassium levels attain 10 mEq/L, the SA conduction no longer exists and passive junctional pacemakers supervene the electrical stimulation of the myocardium (accelerated junctional rhythm). This is followed by progressive widening of the QRS complex and the T-wave with obliteration of the ST-segment, so that the T-wave originates from the S-wave."

[18/07/20, 11:35:52 PM] UG Student 3: https://www.mdmag.com/medical-news/electrophysiologic_basis

[18/07/20, 11:37:41 PM] UG Student 3: Sir according to this article, I don’t think those are delta waves. Rather junctional rhythm with hidden p waves.

[19/07/20, 9:37:14 AM] PG post residency 1: 👍excellent. 

Looking forward to your active learning log

[19/07/20, 11:02:43 AM] UG Student 3: Thank you sir. 

Yes sir I will do it.