Paced percentages

Percentages

by piglet22 - 2024-06-19 04:27:42

Hello 

At the last F2F about 4 years ago, it was as near enough 100% both chambers.

I largely don't worry too much as things pretty followed their prediction, ie the condition progressively got worse over the years.

Rate response is on and that's all I know.

What has changed recently is my exercise toleration which has dropped dramatically. Bisoprolol at 10 mg (reduced by me to 7.5 mg) is probably to blame. I don't get heart rates significantly above the IPG base rate of 70 BPM.

Pacing percentages will matter sometime in the next 12 months when the device is replaced and presumably I'll have external pacing for the first time.

Paced Percentages

by Gemita - 2024-06-19 06:09:03

Amy, my last dual chamber pacemaker report showed around 98% right atrium pacing with approx 4% right ventricle pacing, but these percentages frequently change depending on factors like Lower Rate Limit setting, Rate Response setting, our lifestyle (how much we depend on our pacemaker), our heart condition or other health conditions, any medication we are taking and so on.  My Rate Response setting is off at the moment since it was found to be a trigger for ectopic beats. 

If you don't have CRT, you may wish to read the attached links on Right Ventricular (RV) pacing burden which you will need to copy and paste into your main browser to open.  Pacing induced cardiomyopathy (PICM) is defined as a drop in left ventricular ejection fraction (LVEF) due to a high amount of RV pacing. Although PICM occurs with chronic, and occasionally, with an acute high burden of RV pacing, the minimum burden of RV pacing inducing PICM is not completely clear.

You will see from the first link, a statistically significant decrease in LVEF was found in patients with more than 40% RV pacing, but not in patients with less than 40% RV pacing, suggesting that 40% of RV pacing is the likely threshold for producing left ventricular systolic dysfunction and cardiomyopathy.  It has to be said though that not all patients with a high burden of RV pacing will go on to experience a deterioration in their heart function since multiple risk factors for PICM have been found (see second abstract link).

Further my doctor told me that a susceptible patient would likely see signs of loss of synchrony between the two ventricles at a very early stage in their pacing journey (say within the first few years of a high burden of RV pacing) when an upgrade of their pacing system would be offered, for example they might be upgraded to a CRT device.  If no early adverse effects were seen, it would likely never happen according to my doctor.

So the take home message is that if RV pacing can be controlled and kept reasonably low, this might be beneficial for those without a CRT device.  However, many members without CRT pacing are pacemaker dependent and pace 100% in their RV and have been doing so for years without any difficulty.  Providing your doctors keep a close eye on things, by having regular echocardiograms for example, you should remain safe.  I see from your posts that you require a high degree of RV pacing support.  It would therefore be inappropriate to try to reduce the amount of your RV pacing (through settings changes) when you clearly need it.  

https://www.ahajournals.org/doi/10.1161/circ.144.suppl_1.11902

https://pubmed.ncbi.nlm.nih.gov/34689900/

https://www.pacemakerclub.com/message/43651/risks-of-long-term-rv-pacing

100 % Paced in RV

by SeenBetterDays - 2024-06-19 11:02:35

Hi Amy

I am minimally paced in my right atrium and 100% paced in my left ventricle due to complete heart block (a non functioning AV node).  I experienced a significant drop in my ejection fraction during my first year of pacing and elected to have a His bundle lead inserted as I was diagnosed with probable pacemaker induced cardiomyopathy due to the heavy burden of right ventricular pacing.  As Gemita has pointed out this will certainly not be the scenario for many who have a high percentage of right ventricular pacing. It is helpful though to report any troubling symptoms to your medical team and ideally have regular echos just to monitor ejection fraction and any problematic dyssynchrony in the ventricles.  As long as you are feeling healthy and well I wouldn't focus too much on the percentages.  

Amending my Last Post

by SeenBetterDays - 2024-06-19 11:06:46

Sorry Amy, I should have made that clearer.  I was 100% paced in my right ventricle with my first pacemaker but now am 100% His bundle paced (my brain is a bit foggy today!)

Pacing

by Lavender - 2024-06-19 22:23:17

Ventricle pacing over 40% doesn't increase chances of heart failure. I pace 100% in my ventricles and if not, my chances of death would be great! 
 

My atria works pretty good on its own so my rate response isn't on.