may need 3rd electrode…

I hadn't downloaded my pacemaker for a couple of years and just discovered that my ventricles went from 11% dependent to 100% dependent.  The electro technician was explaining that sometimes the left ventricle which doesn't have a lead could get kind of asymmetrical, and it could lead to heart failure. It looks like I have a complete heart block now. how much harder is it to get a lead into the left ventricle than the right?  It must be more difficult than the right since it's high pressure 🤔  any comments or suggestions would be appreciated thanks everyone! 


3rd lead - CRT - and lead placement

by crustyg - 2021-11-01 04:50:08

What the tech was referring to is LV remodelling from non-physiological pacing via the RV apex - which is the common placement of an RV lead.  This reduces the effectiveness of each contraction of the LV and this can be measured by percentage LV ejection fraction (%LVEF), which is estimated using an echocardiogram, or sometimes, MRI.  This is Cardiac Resynchronisation Therapy (CRT).

The fix for this - which can take months to show an improvement and doesn't *always* work - is to change the PM unit and add a third lead that stimulates the LV directly, much more nearly as the normal conduction system would achieve.

You're correct, it's not easy to get a lead into the LV, so they don't try.  The LV pacing lead is actually introduced into the coronary sinus (where the return blood from the coronary arteries empties into the RA just above the tricuspid valve), and advanced down until it can be shown to be making electrical contact with the LV muscle directly (and the techs can show it 'capturing').  If you look at some diagrams of the heart's structure and blood supply you can see that the coronary sinus fairly quickly reaches the LV muscle).

Best of luck and hope that helps.

Third lead

by AgentX86 - 2021-11-01 10:13:09

There's not enough information here to worry about a third lead. You'd have to have an echocardiogram to find the LV ejection fraction before deciding. Being 100% dependent just means that you AV isn't working at all or is slower than the PM is set. LV remodeling occurs in only a small fraction of the people who are LV paced. You'll have  an echocardiogram to determine your LVEF before you go any further.


echoing the others

by Tracey_E - 2021-11-01 10:22:08

Pacing more doesn't necessarily mean you'll need the third lead, it just means heart block did what heart block usually does- progress. That is perfectly normal for heart block and many of us here have been 100% paced for many years without needing the extra lead. I've been 100% ventricular paced since 1994, my ejection fraction was 63 at my last echo, which is high even for someone not paced. I asked my doctor about eventually needing the third lead. He said it happens well under 10% of the time, and if a patient can go 5 years paced without EF dropping, he almost never sees it happen after that. Unless you are symptomatic, unless you have an echo that shows significantly dropped EF, don't sweat it. 

for what its worth

by dwelch - 2021-11-01 22:10:06

complete heart block from birth, over 30 years with pacers.  my current pacer, number 5 is because my EF dropped under 40 enough that it was time for a biventrical.  so I have an LV and RV lead now.  And as mentioned above by folks, 6 or 12 months later on the next echo, my EF did come up.  It may not change, it may keep it from dropping, or it may bring it up.


3rd lead

by Tulp - 2021-11-02 04:04:07

A 3rd lead might be à good way for the heart to beat symmetrically.

It is more challenging, but as usual as the two others.

My EF went from 27 to 40% on 3 months with a CRT-D.




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