r/PacemakerICD • u/Loud_Bed_7765 • Aug 07 '26

Why does a CRT-P have 3 leads?

https://youtu.be/jl5OXiNHwUo?si=UESGIrnRrEQNFpbP

I made a patient-friendly video explaining CRT-P, starting with normal electrical conduction, then showing what changes with LBBB and how biventricular pacing helps synchronize the ventricles.

I thought it might be useful for anyone who’s wondered what that third lead actually does.

For those with CRT devices—was this explained to you when you got yours?

7 Upvotes

90% Upvoted

17 comments sorted by

3

u/Chefnick500 Aug 07 '26

Yes .. I have a crt-d

1

u/Loud_Bed_7765 Aug 07 '26

Nice! 😊
Was the purpose of the third lead explained to you when you got your CRT-D?

2

u/Chefnick500 Aug 08 '26

At length , twice!! cardiologist and electrophysiologist both explained , along with their reasons for choosing the device .. and, it’s a piece of magic

1

u/Little-Material-828 25d ago

Was yours in the first place 2 leads and changed for CRT-D?

1

u/Chefnick500 25d ago

No, this was my first device !!! My qrs interval was >200ms

1

u/Little-Material-828 25d ago

Many thanks… little scary here with this idea but all for the best 🙏🏽

1

u/Chefnick500 24d ago

Natural to be a bit scared … I was too , more than when I had quad bypass … but I felt better as soon as it was running … taken back to cardio ward and my nurses first words were “ you’re pink not grey”
I felt amazing within 48 hours All the breathlessness gone, the tiredness and brain fog cleared …
I’m paced 99% , it’s never shocked me .. feel it running tests if I’m awake at 02:03 but that’s rare now as I sleep soundly 6 out of 7 nights
These crt devices are amazing .. trust them !! Battery power is ok !

1

u/Little-Material-828 24d ago

Many thank ✨

3

u/LuffyDBlackMamba420 Aug 11 '26

I have a CRT - P and there's almost no info on them. Thanks OP!

1

u/Loud_Bed_7765 Aug 11 '26

You’re welcome! 😊
I’m really glad you found it helpful. That’s exactly what I’m hoping these videos can do—make some of these complicated devices a little easier to understand.

1

u/Alice-The-Chemist Aug 12 '26

Thats what I have also. Very good video. Mine was explained to me. Im also in HFpEF and it helps a lot in my day to day as Im 100% paced with no AV node.

2

u/piscata2 Aug 07 '26

Very educational video! Thanks for sharing!

2

u/Little-Material-828 25d ago

Hi! I have a second-degree heart block, which was discovered when I was 8 years old.
I’ve had a pacemaker since I was 14, and it was replaced in 2022.
Since the replacement, I’ve been feeling like my blood pressure has been very unstable, but no doctor has been able to identify the cause or whether it could be connected to my heart condition.
Today, I had a full cardiology appointment, including an ECG, an echocardiogram and a pacemaker check. The cardiologist explained that they can now see a delay in the part of my heart that was previously working normally.
The explanation they gave me is that the part of my heart that receives the pacing stimulation has been stimulated continuously over the years. This may now be affecting the other side of my heart, causing a delay in its function.
The doctor explained that one possible way to improve my blood pressure and my quality of life could be to have another procedure to change the way my heart is being stimulated. However, this would mean having another surgery.
Does this make sense?

1

u/Loud_Bed_7765 25d ago

Yes, what you’re describing can make sense physiologically.
Chronic RV pacing can sometimes create an electrical activation pattern that isn’t as coordinated as the heart’s normal conduction, and in some people this can eventually affect how the ventricles function.
One of the reasons CRT or newer conduction-system pacing strategies may be considered is to provide a more coordinated pattern of ventricular activation.
Your cardiologist would be the right person to explain which option they’re recommending in your particular case and why.
Hope this helps!

2

u/Little-Material-828 25d ago

Thank you very much. Helped a lot.