Normal pulse range for 100% pacing with BiV CRT?

BiVP %

by USMC-Pacer - 2024-09-11 21:01:22

They want to get your BiVP% as close to 100% as possible for the CRT to do it's magic syncronizing and strengthening your left and right ventricles. As you stated, PVCs, Afib, and other arrythmias are detrimental the the effectiveness of the CRT.

Long article but explains it better than I can:

https://journals.lww.com/co-cardiology/Fulltext/2013/01000/The_importance_of_increased_percentage_of.9.aspx

Not sure if this helps?

by Gemita - 2024-09-12 04:54:23

TWVNET I will attempt to answer your main headline question:  A normal pulse range is between 60-100 bpm.  Anything lower would be regarded as bradycardia, anything higher would be tachycardia.  I don’t see why this should be any different with BiVentricular CRT pacing. 

100% pacing won't mean that our pulse will stay at our set base rate of say 70 bpm.  If if did we would struggle to be active.  A static pulse could point to chronotropic incompetence (CI) which is another subject.  I have a fairly static pulse stuck at between 70-80 bpm due to CI.  This still needs to be addressed although I manage well enough at the moment with my activities.  

Your second question what does 100% pacing actually mean is more difficult to answer because so many variables can affect our pacing percentages.  Variables like

- your degree of heart block or sinus node disease.  Minimal, intermittent disease may only require lower levels of pacing support, more serious levels of disease and progression may require 100% pacing support.  

- our medication can slow down our heart rate, slowing down conduction through our AV Node and causing worsening sinus node or block symptoms.  This is why some of us have a pacemaker to keep our heart rates from falling below our set lower rate limit, allowing our rate control/anti arrhythmic meds to "safely" control a fast arrhythmia without causing worsening bradycardia.  This was one of the reasons why I had a pacemaker implanted because I had Atrial Fibrillation with a rapid ventricular response rate.  The other reason was for syncope.

- other important variables are pacemaker settings and arrhythmias.  For example at a higher base rate setting of say 70-80 bpm you will probably be pacing more than if your base rate were set at 60 bpm.  I note you have troublesome PVCs.  These can affect your need for pacing too although pacemakers are unable to control PVCs.  Some arrhythmias can be pacemaker mediated and settings may need adjusting.

So what is 100% pacing support?   I would define it as the amount of pacing needed to make us largely symptom free and to improve cardiac output.  The percentage pacing that is needed at any one time would depend on our personal variables, like our pacemaker settings, whether we are experiencing arrhythmias, whether we are taking rate lowering or anti arrhythmic meds which will slow conduction, our exercise demands, other health conditions and things like this.   A high degree of pacing recorded in each chamber:  right atrium, right ventricle, left ventricle for example will give us an idea of our dependency on pacing, but as mentioned, variables can affect our level of pacing support needed.

Importantly, PVCs (premature ventricular contractions) are known to reduce the percentage of biventricular pacing in patients with cardiac resynchronization therapy, decreasing the clinical response to treatment, so I can understand completely your need to get this rhythm disturbance under firm control.  Good luck