What do you think?

Hello,

I am needing to go back to the pacemaker clinic to see if they can help with an emerging minor issue with how I am responding to my pacemaker settings and would appreciate if anyone has experienced similar so that I know that is the likely cause.

My  dual lead pacemaker is set such that it is only sensing and pacing in the ventricles and will only pace if the ventricular beat is less than 40bpm. It's not really relevant why its set to this.

This means that when there is a missed beat the pacemaker will wait a whole 1.5 seconds before providing a beat.

Until the last month this has barely been an issue but now when at rest I have an uncomfortable thud or strange feeling when the missed beat is then finally paced. This is happening for long periods of time when I am sat down working or in the evening.

Would you think this thud and strange sensation is due the ventricles being paced so late?

 

 

 


7 Comments

Yes.

by crustyg - 2023-02-22 17:49:59

You still have an intact nerve supply to your heart?  Assuming that the answer is yes, then most certainly the thud from a very delayed contraction is due to the long delay.

Nerve supply to the heart (from a motor perspective, not sensory == heart muscle pain) does two main things: 1 controls rate of heart by increasing pace rate from normal SA-node.  2 Controls intensity of contraction - how vigorously does the heart muscle contract when activation happens.

Sympathetic activation increases heart rate, decreases refractory period of AV-node and increases the intensity of heart muscle contraction when activation (==beat) occurs.  So your heart does nothing for 1.5s.  BP is falling (there's only so much elasticity in aorta to help maintain blood pressure), sympathetic system activates, tells heart to beat *hard*, finally activation happens => thud, as LV contracts really hard.

Make sense?

Yes, I do too

by Gemita - 2023-02-22 19:09:01

John, it sounds as though you are having benign arrhythmias, either atrial or ventricular premature beats, probably not helped by your settings delays like MVP (managed ventricular pacing) and NCAP (Non Competitive Atrial Pacing) which both delay the onset of pacing.  As well as this, premature beats are early beats, followed by a longish pause and combine this with your settings delays, I am not surprised that you are getting some nasty thuds at the end of what must seem like a never ending pause.  I get them all the time and have just had NCAP turned off and what a difference it has so far made.

I know you are reluctant to pace more than you have to in your ventricles, but I wonder if you should go back and get those settings adjusted?   A higher Base Rate would certainly help as well as possible adjustments to other settings as already mentioned. 

Get your electrolytes checked too John because there are many causes for premature beats or ?other arrhythmias which may be present and they may not only be caused by your Settings.  It also has to be said that your heart condition may have changed since you were last checked, so you need an early appointment to identify the rhythm disturbance present.

Interesting

by piglet22 - 2023-02-23 09:14:12

Hello

I'm suffering from very similar symptoms which I may or may not have mentioned here before.

I'm skipping beats despite being paced at 60 bpm. I can get down to 31bpm and this can go on for hours.

The similar part of it is that my symptoms also occur in the evening and at night. In 18 years with the PM in place, this has never happened before.

I have drawn the conclusion that the skipping happens shortly after relaxing from getting back from a daily fairly strenuous walk. I'll be sitting down, then the chest sensations start and at my radial pulse, the skipped beats are obvious.

I'm wondering if this does go on at other times, but while I'm active I don't notice it, or the demand takes over and masks it.

I've spoken to the physiologists about it but I get the impression that they aren't too bothered but I'm chasing it up through my GP.

A setting of 40 bpm does seem strange but should be on your PM card as IPG rate. My card says IPG 60 per minute.

I'm wondering about your calculations.

If I miss a beat at 60 bpm, then it's two seconds when the next one kicks in. At 40 bpm that would be longer.

Just an aside, I had a chest X-ray this morning and had the opportunity to look at it afterwards. Fascinating to see the device and the two leads, one right down at the bottom of the heart shadow. One lead has a kink in it. I hope that doesn't matter.

The device, Medtronics Endura, clearly shows as one-half opaque, presume the battery side and the other transparent with all the components on their PCB.

The po faced radiologist said I couldn't photograph it. As if it's a state secret.

I always wonder at the miracle of microelectronics and what people did before these wonderful devices.

I do electronics and microcontroller programming and the software side of these devices must have taken a lot of people a lot of effort to get where we are now. Some of these chips are so small you have to work under a microscope. The chip has the full instruction set, plus memory plus whatever communications it uses like Bluetooth or Near Field Communications

Thanks and interesting piglet - could you give more info maybe?

by quikjraw - 2023-02-23 09:44:13

Thanks Crusty and Gemita,

They have managed to fit me in at the hospital in early March - they were very helpful on the phone. It sounds like it is the long pause and thud that I am feeling everytime I am relaxed at the moment.

When they connect at the appointment I assume they will know for certain that it is long pauses and paced beats that is happening rather than PVC or other issues.

I wonder how much the pause has on extra blood being present in the heart during the extra time it waits before beating?

Piglet

My settings are at VVI40, I have researched this and it works very simply like this, if the ventricle lead has not seen a beat after 60/40 or 1.5 seconds (a heart rate of 40bpm) then it will add a paced beat.

Therefore if I am in av node heart block at low heart rates and my ventricle was NOT going to beat of its own accord then after 1.5 seconds a paced beat will appear. 

I can also sense it on my wrist pulse as a long pause like you explained.

It is interesting that you say you notice it more after some exercise - I have been doing more exercise recently so it could be that causing the increase in heart block events when I am at rest.

In your case however I am not sure what your pacemaker setting is as settings like DDD for example work differently from VVI.

Do you know any more about your settings other than the lPG 60 you mentioned?

 

 

 

Increase in Base Rate

by SeenBetterDays - 2023-02-23 10:23:29

I would agree with Gemita that you might want to discuss pushing up your base rate as this should prevent the long pauses you are experiencing. I suppose it is trying to find the right balance between minimising ventricular pacing and avoiding uncomfortable symptoms like the ones you've described. I'm sure that a device interrogation will help to establish exactly what's going on. Maybe keep a note of times when you are particularly symptomatic and any other factors which may create a pattern for your arrhythmias such as activity level, diet, stress stress level etc. It pays to be armed with as much information as possible for your appointment.  Hope it goes well and you can get a positive strategy to help moving forward.

Quikjraw

by piglet22 - 2023-02-24 05:42:34

I can't add much more about settings than I gave.

18 years of never getting bpm below 60 and now in the space of a month, multiple episodes of 30, 40, 50 bpm.

I can be sitting watching the TV, then I get the chest sensation, go to my wrist feel the pauses.

If I get up, I'm feeling dizzy and grabbing the door frame. My BP can be very low. It's pre-PM all over again.

I'm on the second PM and it's over 7 years old and at 100% dependency, it's working hard.

I had an ECG at the GP surgery some weeks ago as through frustration I'm chasing this up through them.

I had a 12-lead ECG which they reported as normal.

I have access to my full medical record and out of the blue last night appeared a report from someone else who has looked at the ECG at what they say is totally different to normal, in fact I was shocked to read the number of problems highlighted.

There was also a copy of the ECG.

I'm no expert on interpreting traces, but it looked pretty awful. Instead of regularly spaced waves of the same amplitude, these were all over the place, from almost nothing to large positive and negative going spikes.

This has really put the cat amongst the pigeons and I'm hoping that this might stir someone to do something.

From 6-monthly face to face with ECG, it's gone to over 2 years now without seeing anyone and no ECGs.

"They" the NHS have cut this service to the bone and this is the outcome.

Good luck with your problems, at least you know you aren't alone with your symptoms. The symptoms with relaxation are pretty similar.

SeenBetterDays

by piglet22 - 2023-02-24 06:02:47

I too keep very close records at home and have done for many years.

I include BP, blood glucose (non-diabetic hyperglycemia), temperature (Covid) and oxygen saturation.

The way I look at it is that if I'm lucky, I might get a blood test once a year at the surgery.

Getting readings at home under normal living conditions is far better than stressful visits to the surgery. One bad result there can put you on the wrong treatment for decades.

When I first thought there was something wrong with my heart it took a long time for the GP to acknowlege it.

When I went to the consulatant, he wrote to my GP and I have a copy.

The striking bit was the phrase "this man came armed with information"

I got the impression from "armed" that they don't like lay-people doing a bit on their own initiative.

Now older and bolder, I don't respect that sort of attitude and instead of taking bits of paper to consultations, I take the laptop.

An Excel chart of 2 years data on bpm, mainly normal, then a month's worth of erratic data is not so easy to ignore.

The disappointing but not surprising thing is having to struggle to be heard.

As Spike Milligan said "I told you I was ill" and that is on his gravestone.

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You’re a battery-operated lover.

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