best PM for SSS

Hello everyone. I am a 48 year old male with a diagnosis of  Sick sinus syndrome. I have not yet had a PM implanted but it seems that it might be my best permanent option to get a better quality of life: general tireness, extra systoles at times, and some light headaches.  I have never had any syncopes and no AV block or AF. I still work out several times a week so not suffering from chronic incompetence. But heart rate is in the low end below 50 due to being low at night in particular.  I would ideally like to have a leadless PM implanted as this seems to be the future with a quick recovery time but as I understand people with SSS need a dual chamber pacing and these are not yet available in the leadless form. On the other hand there has also been some suggestions saying that AAIR pacing could be sufficient for people only suffering from SSS without further complications e.g.

But I guess none of the leadless PMs on the market today are AAIR paced only VVRI paced from e.g. Medtronic (Micra av not realy qualifying here even if there is some Atrial stimulation) or Abbott (that acquired St Jude). Any other firms working in this field? 

Any feedback here woould be most appreciated. br MG


Why PM?

by ar_vin - 2021-07-31 20:01:41

Just a lower HR is not reason enough for a PM implant. However, many rhythm disorders can be progressive - your EP will consider all that before choosing a particular device.

Maybe it's a good idea for you to assess your options and allow the technologies to evolve rather than rush and get an implant.

At your young age you have to consider that you'll likely need several replacement devices as each one reaches end of life. It's unclear if the leadless devices can be extracted without significant risk - if the device must be left in place before new devices are implanted you have to consider how that would work.

You don't say where you are; I'd suggest seeking out a competent EP at a hospital that does a lot of procedures in younger folks like you before you go under the knife. You also need to clearly communicate your post implant expectations as far as activity levels etc.

But you're smart in seeking to learn more - read about your condition and ask questions here and find an excellent EP to consult.




Is there a Best PM for S.S.S ?

by IAN MC - 2021-08-01 09:02:47

When your sinus node starts to malfunction  it can cause your heart rate to become too slow, irregular, too fast or a mixture of all three.

Like you I started off with just a lazy sinus-node, resulting in bradycardia. After a couple of years though, I developed Chronotropic Incompetence which confirms ar_vin's point that SSS can be a progressive condition.

There are four major makes of PM....Medtronic, Boston Scientific, St Jude and Biotronik. As far as treating bradycardia goes, there is nothing to choose between any of them. They will all increase your HR to normal levels when necessary.

Local factors such as hospital stock-levels, relationship with company / rep etc will be factors in determining which brand is chosen.

Should you  develop C.I though then there are subtle differences in the way their Rate Response function works, This is only important if you take part in certain activities such as serious cycling. Otherwise all brands are moderately successful in varying the HR according to the oxygen-demands caused by exercise.

As to when you get a PM .. that should be a joint decision between yourself and your EP ( with SSS the decision is usually symptom-driven )

Best of luck



Is there a Best PM for S.S.S ?

by MG73 - 2021-08-01 10:32:41

Thanks for the comments above from both of you. Yes when symptoms become too troublesome and the diagnosis of SSS is firmly established it is relevant to discuss a PM.I still want to rule out e.g. sarcoid due to some symptoms that could fit this cause so I am asking to get a cardiac MRI scan and hope this will be approved. But most likely it will ultimately be determined to be SSS of idiopatihic reasoning - although I suspect some virus infections in the past can have caused this. but the end result is the same.

In terms of which PM to select I was hoping as mentioned that the leadless variants would further advance soon. I am not so concerned about not getting them out when they expire- there are room for some at least and the battery time should be quite okay. Boston is even trialing one now where it can be easily removed again. BUT unfortunately none of them are AAIR paced or dual based. They might come along in some years (5-10 yrs?) as there is a big market for it - but that will not help me here or now.

Or do any one have some interesting news here? Br MG

There's a lot wrong in your thinking

by crustyg - 2021-08-01 11:08:56

Well, you did invite comment.

Sick Sinus Syndrome does NOT need a dual lead PM, and most certainly does not need vent-pacing instead of atrial pacing.  Assuming that's all that you have (at the moment) then any old single lead PM will do fine.  It will replace your failing SA-node and deliver electrical activations which will reach your (healthy) AV-node and then progress down your healthy bundles to deliver the correct activation to each ventricle - no risk of LV remodelling etc.

Trouble is, whatever process has damaged your SA-node will probably progress and give you Chronotropic Incompetence eventually, in which case you will really care about the cleverness of your PM's Rate Response algorithm and the sensor feeds that can drive RR.

My own EP-doc told me that DANPACE showed that implanting single lead (RA) PMs was not a good idea.  I couldn't disagree more: many of the EP-docs who entered patients into DANPACE broke protocol and fitted dual-lead PMs when a single lead PM was all that was indicated.  Many of the single-lead PMs that apparently later needed to be upgraded to dual lead were in fact box-replacements (not all PMs last 7-8years).  My dual-chamber, dual-lead PM is configured AAIR (for SSS+CI).  The vent lead does nothing.

I can understand the apparent attraction of a leadless PM and the very short recovery time, but, as others have pointed out, you will need several changes to last you for 30years, and no-one has any real idea how this will be achieved.  Much worse is that it's very likely that a leadless PM activating the RV will lead to LV remodelling with all of its problems, with no guarantee that putting in a 3-lead CRT will fix the resulting damage to your heart.  There's no market for a leadless RA PM - most of the patients who might benefit from it will have significant AV-node damage, so it's the RV that needs to be driven.  And the RA is really thin - not enough muscle to provide a sensible anchor without a significant risk of perforating the heart =>pericardial bleed =>The End (unless you're really lucky).

If you were 88years old, I'd say, leadless PM - great idea. 78years old, probably good idea. 68years old, well maybe.  58years, really bad idea, 48years old - get yourself a good lawyer because any registered medical practitioner who is recommending a leadless PM for simple SSS at your age is either incompetent or dishonest (being paid to recommend it).

Clear enough?

Thanks for your comments

by MG73 - 2021-08-01 16:24:14

Hi Crustyg,

Appreciate your comments and your insight into the subject. You raise some good points.

Just to recap you mention that a single lead (RA) PM should do fine if you only have SSS and maybe also CI and this should minimize the risk of LV remodelling etc.  Noted on the importance of the PM's Rate Response algorithm and the sensor feeds that can drive RR in particular if you develop CI. From one of the earlier responses most PM should be similar unless you are a very intensive cycklist etc.

You are also tight that there is a risk that whatever causes the SA - node to not function properly could lead to further complications done the road - with the AV note, AF etc. Are their any good studies showing that this can often be stopped if a PM is inserted while the problem is still only defined as being SSS and CI? or is the PM only a symptomatic treatment in this regard?

On the note that a leadless PM activating the RV will lead to LV remodelling and the trouble this could cause - I am wondering how that would be different from the above mentioned single lead (RA) PM where you see this as less of a risk? Maybe I am missing a point here :=) - are you referring to a VVRI paced leadless PM or the hypothetical leadless RA PM mentioned? Anyway you are right that the best market for a leadless PM would be with dual pacing as many even with SSS also have problems with the AV node etc.

In the future I do see many switching to the leadless one when they will be ready in a dual-function - in particular younger users - despire of the number of replacements needed - in particular if they find a reliable process to remove them each time. But we shall see and cost will also be a prohibitive factor for many in the first years after they are launched.

In ending in my case am I right in stating that maybe  a dual-chamber, dual-lead PM configured AAIR (for SSS+CI) would be my best option?  Where I have the vent lead as a back up if I should progress and experience other issues such as AV node etc?  This is of course a decision I need to take with my EP and if I indeed only have SSS and nothing else at this stage. Br MG

In answer to your last Q: probably, yes

by crustyg - 2021-08-01 17:53:11

There are technical reasons why fitting two leads at initial implantation is a good idea, even if the RV lead does nothing for some years.

There is no possibility of LV-remodelling if the electrical stimulation comes from above the AV-node: the remodelling (which leads to reduced LV function) is directly caused by activation from the wrong direction - the apex of the inter-ventricular septum - which can't happen if your activations are initiated from above (i.e. the RA).  And it doesn't always occur.

There will never be a dual-chamber leadless PM, for the reasons I gave before.

I've seen *some* soft evidence that 'outpacing' the irritable clumps of cells in the bradycardic RA *may* reduce the likelihood of developing AFib/Aflut (although I accept that they probably have very different causative mechanisms) - it's the argument that I used to get my EP-doc to give me a more realistic (==higher) maxHR on my PM.  The basic concept is 'outpacing' the irritable cells that might otherwise lead to some Atrial-based tachyarrhythmia.  I'm 2+years in: ask me in 5years time how this has worked out for me!

HIS-Bundle Pacing

by Gotrhythm - 2021-08-03 15:12:36

I mention HBP not because I'm suggesting it but because it's one more option for SSS. The advantage is that it avoids the problems of remodling. The disadvantage is that more surgical skill is required to position the lead into the very tiny bundle of His. Although HBP is done much more often these days, I would still want to go somewhere the surgeons get lots of practice.

About SSS progressing. I doubt if any pacemaker will prevent SSS from getting worse because the pacemaker does nothing about whatever is causing the sinus node to fail.

When I first got my dual lead St Jude pacemaker, I was paced only about 35%. So I was concerned when I learned my SSS would get worse over time. But since then it has gotten worse and today I'm pacemaker dependent.

And here's the thing I've found out. My sinus node being basically kaput makes no difference to me, and it doesn't change what the pacemaker does. My pacemaker paced as often as it needed to then, and it paces as often as it needs to now. 

When you think about it, that's pretty marvelous. Our device means the SSS can get worse and worse, but we don't have to go downhill with it. We feel the same. Feel fine, in fact. How many worsening conditions can you say that of?


by AgentX86 - 2021-08-03 16:48:54

I think the point is that no ventrical lead is needed at all if SSS or SSS+CI is the only problem. It may, or not, be wise to place one just in case but a one into the bundle of His, or a CRT PM, would be gross overkill.

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