DDD mode to AAI<=>DDD

I have a Medtronic Adapta, installed after valve surgery for heart block. 10 months post-op had a PM check up and nurse said I was not pacer dependent. For the whole time I was there I did my own AV conduction. Because of this the EP changed my programming from DDD to AAI<=>DDD. Basically when I have conduction the PM just watches the heart, if 2 ventricle beats are missed the PM switches to DDD mode to keep the ventricles going. The PM does periodic checks to see if conduction has returned.

Does anyone else have this mode programmed, or has anyone had AV conduction return after so long??? The surgeon said it was possible, but I didn't thin after so long.
Cam

6 Comments

I am...

by golden_snitch - 2011-05-14 04:05:42

Hi!

I have this mode programmed in my Sorin Reply DR, and I thank God for that! As you might know, a lot of right ventricular pacing increases the risk to develop heart failure and/or atrial fibrillation, so it's very important to minimize ventricular pacing. A "mode switch" is way more effective than a programmed AV-delay in doing so. When my pacer is set in DDDR I have around 30-40% ventricular pacing, when it's in mode switch AAIR <=> DDDR I have less than 10%, most of the time only 2-3%. I do feel some heart blocks as the pacer does not kick in with every single heart block, but I got used to that and it's tolerable.

My mode is: 1st degree heart block needs 7 prolonged PQ-intervalls, before the ventricular lead kicks in; 2nd degree heart block needs 3 out of 12 P-waves blocked before mode switch; 3rd degree heart block needs two consecutive P-waves blocked before mode switch ( I also have a pause suppression programmed making sure that this can't lead to a long pause).

Yes, an AV-node can recuperate, especially in young patients. There is a lot our heart/body can achieve that we have no idea of. My sinus node has been ablated four times with more than 120 "burns", and still it grows back (doesn't function 100%, but sometimes I'm in sinus rhythm).

Best wishes
Inga

Me Too

by Creaky - 2011-05-14 06:05:12

I have the same mode programmed in my Medtronic Adapta. They tell me that my sinus rhythm is good, so it just monitors the ventricle and works when needed. I still feel the random skip but try to ignore that.
However, an unrelated issue surfaced-
My PM was implanted in Sept 2010 and I've already developed an insulation problem with the ventricular lead. This required them to change that lead from bipolar to unipolar. We are still monitoring to see if that work around is successful. So far so good.
Good luck.
Harry

Thanks

by camgough - 2011-05-15 09:05:42

Thanks Inga and Harry,
I still do not really believe that my conduction has returned and want to see to EP clinic again soon to confrim. I would be so excited if the MVP was working and reducing my right ventricle pacing. Seems too good to be true!

I have been feeling a few odd "thumps" and other feelings from time to time. What does a block feel like, or what does the mode switch feel like?

Also the day after the new settings, when exercising my HR would get to 138 and then drop to 78 while keeping the same pace. Similar to when in DDD mode and I would hit the MTR.

The next day I could get to 170 no problem and deacrase normally as I cooled down.

My DDD settings are 50l ow, 200 high. Is the AAI set seperatly, or is it even set if all it does is watch the heart?

Sorry for all the questions, all the help is appreciated!
Cam

Mode switch

by golden_snitch - 2011-05-16 03:05:46

Hi Cam!

I always feel several missed beats before the mode switch kicks in. That's because I often have 2nd degree heart block, and need 3 out of 12 p-waves blocked before the mode switches. My rhythm sometimes gets quite irregular before the mode switch. Also, when it kicks in, my heart rate is usually getting a bit faster for a short time.

With regards to the minimum/maximum programmed rate AAI and DDD are the same. The only explanation I'd have had for the sudden rate drop was that the maximum tracking or upper rate was set too low, but apparently this is not the case. If it has not happened again, I'd not worry about it too much. Just ask the cardio when you see him next time.

Best wishes
Inga

My EP is stumped.

by camgough - 2011-05-29 08:05:12

Hey everyone. I had another pacemaker appointment last Friday to try and figure out my situation.

I was put on a treadmill while in the AAI-DDD mode and when my HR went to 118 it dropped to 72. Doctor called me off and noted that as my HR went up, heart block developed and for unknown reasons the pacemaker didn't catch the missed ventricle beats.

I was then put back in DDD mode and did the same test without any heart block developing. The doctor did notice a few missed ventricle beats that were not caught by the pacemaker again.

The doctor does not know why the pacemaker missed beats in both modes and said he was stumped and needed to call the company. He said the pacemaker knew the beats were missed but did not step in.

They left me in DDD mode until he can get more info and have me back in. As a side note, for the approx 2 weeks I was in AAI-DDD mode I had 0 mode switches, so for that entire time my heart worked on it's own most of the time.

I am really hoping that they can figure it out so I can go back into AAI-DDD mode permanently.

Any thoughts??
Cam

Back to DDD with Search AV+ on

by camgough - 2011-06-13 11:06:11

OK, so here is the latest news on my Adapta settings. I had a treadmill test last week with the rep and doctor to try and figure things out. I was switched back to the MVP mode (managed ventricle pacing mode, AAI<=>DDD) and at rest my heart was conducting fine. I started on the treadmill and once my HR got to around 120 or I began to block and my HR decreased to 70 or so. The Dr stopped it immediately and the doc and rep looked at the ecg print out and discussed things for several minutes.

They believe that the issue with the MVP mode is that my own natural AV delay is quite long and the pacemaker is unable to pick this up. Unfortunately in MVP mode none of the settings can be altered or changed and are set by the company engneers to benefit the majority. The problem was that during exercise when my own conduction would start to fail or block, the pacemaker did not recognize it needed to change from AAI to DDD.

I was then put in DDD mode and did another quic brisk walk and this time the pacemaker followed my HR into the 140's no problem and paced the ventricles. So the doctor and rep began discussing again how they would keep me in DDD, but reduce unneeded ventricle pacing as much as possible.

These are my new settings, that the rep suggested were quite aggressive and pushing the pacemaker capability to the limits...

MODES Initial DDD Final DDD
Mode Switch ON ON
Detection rate 210bpm 210bpm
Detection duration no delay no delay
Blanked flutter search On Off

All the rated stayed the same. Lower 50ppm, Upper tracking 200ppm, Upper sense 180ppm, ADL rate 95

Intrinstic/AV
Paced AV Initial 150ms New 300ms
Sensed AV 120ms 250ms
Search AV+ Off ON
Max increase to AV 150ms
Rate adaptive AV ON ON
Start rate 80ppm 80ppm
Stop rate 180ppm 180ppm
Maximum offset -40ms -240ms

Refractory/Blanking
PVARP Initial Auto New Auto
Minimum PVARP 250ms 180ms
PVAB 180ms 180ms
Ventricle refractory 230ms 230ms
vent pacing (after A. pace) 28ms 28ms
PMT Intervention, PVC response and ventricle safety pacing all ON.

The only other changes were in the atrial where sensitivity was taken from 0.50mV to 0.35mV ans sensing assurance was turned off. I do not even know what this is. Battery life expected 10.5 - 14 years, likelt 12.5 years left.


There are more settings on my sheet, but these are the major ones that were changed. I can always put the whole report up as a pdf if anyone is interested.

So I guess the bottom line is that these settings will allow my heart to do as much on it's own because the AV delay was increased. Also my HR should be able to get into the 180 range and only periodically block (11:10, 10:9, etc....) as opposed to a 2:1 like I experienced before.....BRUTAL! At my next appt they will be able to tell me how much I am pacing in the ventricles, and I hope it is low! I think it will be primarily when I exercise. The doctor said that my conduction may continue to get better with time, but at the moment these are the right setting. This way I will never drop a ventricle beat, even with eexrcise which was happening with the MVP mode. The Search AV+ feature continually looks for intrinstic AV conduction, times it and changes it's setting automatically to promote intrintic conduction as much as possible, but also pace the ventricle when needed. If it is pacing the ventricle it keeps cheking on conduction and stops pacing when conduction is found.

I guess this is kind of the best of both worlds for now. I should be able to exercise up to 180 before any blocks, and pace on my own as much as possible at rest.

I also did notice on the Sorin website their SafeR pacving mode (like MVP) says that it switched to DDD quickly in exercise, but also extends the AV during rest to promote intrinstic conduction. Anyone have these settings?

Any comments on the new numbers, thoughts or similar experiences gladly welcome. Sorry for the long post!

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