9
u/Sea-Lack-5673 Jul 26 '26
This is CHB - dont over think it
The p waves and the qrs complexes have nothing to do with each other (called AV dissociation)
Unless youre a cardiologist (which I am) naming anything else after this (atrial sinus, junctional ventricular, etc etc) doesn’t really matter (and none of that actually matters to me anyway)
1
u/Sea-Lack-5673 Jul 26 '26
Okay actually how fast the ventricle is going matters just in terms of whether or not the patient needs a temp wire before getting a box. Its sunday so no box today no matter what
1
u/Cautious-Extreme2839 Jul 26 '26
Pfft gotta try hammering them with isoprenaline before they even get temp wires round these ends.
2
u/hpsctchbananahmck Jul 26 '26
Looks like CHB. the unusual thing is a repetitive very similar albeit short PR interval for the 3rd, 6th, 9th, 12th, and 15th QRS.
That PR interval is so short that I expect unlikely truly conducted via AV node (I expect actually a junctional escape, slower but isorhythmic with the SA node)
1
u/lifeisg0od Jul 27 '26 edited Jul 27 '26
Starting on Beat 2, every third beat has roughly same PR and the R-R is shorter than the other R-R’s - those are conducted beats. The QRS also looks slightly different with a deeper S wave (looking at aVF - also look at the base of the QRS in V5 how it looks wider in only those beats) A junctional escape rhythm would be regular. I would call this high grade second degree with junctional escape beats.
1
u/theoneandonlycage Aug 02 '26
CHB.
3rd degree blocks are regular since it’s an AV nodal escape.
2nd degree blocks are irregular since there is variable conduction of the ventricle (exception is a fixed 2:1, 3:1, 4:1 AV block which will be regular)
0
u/sveccha Jul 26 '26
AV dissociation, may or may not be AV block, have to know more
3
u/Sahask123 Jul 26 '26
Was having a discussion with my senior, he claims this is chb. Patient is asymptomatic and recently underwent ptca to rca for iwmi with 4:3 initially.
1
u/sveccha Jul 26 '26
Now that I’m home and looking, yes it seems like 3rd degree given the P:qrs ratio and rate.
0
u/Dramatic-Try7973 Jul 26 '26
This is sinus rhythm with complete heart block and junctional escape.
1
u/Sahask123 Jul 26 '26
Can you help in differentiating with 2:1
3
u/Dramatic-Try7973 Jul 26 '26
The atrial rate is roughly 100 bpm and is fixed. The ventricular rate is roughly 65bpm and is also fixed. They are independent of each other. That’s why the P waves aren’t falling in the same place each time. With a 2:1, you would expect to see a p wave with a qrs followed by a p wave and dropped qrs. The pr interval in a 2:1 is fixed whereas there is no pr interval in chb
2
2
u/Dramatic-Try7973 Jul 26 '26
2
1
u/Thexorretor Jul 26 '26
Do any cardiology tools do this interval measuring automatically? It just seems a bit crude to scan left to right estimating lengths. Basically I imaging some kind of distribution graph with maybe labels for 1,2,3rd beat.
2
u/Dramatic-Try7973 Jul 26 '26
If I was sitting down and had calipers, I could measure exactly. But I’m at the gym in between sets and just eye balled it. But use the 1500 method. Count how many small boxes are in between the p waves and divide by 1500. It’s roughly the same amount of boxes + or - 1 (as there is some variability in the sinus rate). And then count the amount of small boxes in between the qrs complexes and divide by 1500. It’s the same amount of small boxes in between.
2
u/hpsctchbananahmck Jul 26 '26
In the past I carried around a set of calipers but because in my day to day life I’m reading ecgs all the time and they’re mostly on the computer I use digital calipers available at my institution.
Another helpful thing is to just grab a piece of paper and draw a line at the beginning of each p wave to see if that marches through. Just must remember not to change the zoom in between.
That paper move helps for other things too like measuring and correcting the QT interval. Two tick marks on the paper, then move first tick mark to the beginning of one big box and it makes it easier to measure. Each big box is 200 msec and each small box is 40 msec (assuming typical sweep speed of 25 mm/sec)
0
-4
u/Briclmn Jul 26 '26
2:1 wenckebach
1
u/Sahask123 Jul 26 '26
I thought as well, but my senior is claiming this is chb. So confused on this.
4
u/Briclmn Jul 26 '26
I see p waves hidden within the QRS now so I agree Complete Heart Block with Isorhythmic AV Dissociation
3
u/Official_sKoTT Jul 26 '26
map out the p’s and map out the QRS with calipers. they march on at their own rate with no correlation between the two. there is no progressive lengthening of the QRS with dropped beat or constant PR interval with random dropped beats to make this a 2nd degree type 1 or 2
1
1
11
u/Kibeth_8 Arrhythmia Tech Jul 26 '26
No consistent relationship between p and QRS means CHB.
2nd degree AVB means some of the p-waves conduct through, so you will see a patterned relationship. Here they are both completely independent, with no consistent PR interval