Medtronic Micra - Anyone part of the Marvel 2 study?

Curious

by pbbrown7 - 2019-12-21 20:14:24

I'd be curious too. My doctor wanted me to wait and get this Micra AV but my 2nd degree block keeps getting worse and now I'm scheduled for a regular dual chamber on January 2nd. My heart rate gets to 37 sometimes at night. So I may be better off with a standard pm over the Micra that only beats the ventricles 

Question

by SNORTINGDONKEY - 2019-12-21 21:08:19

So you are saying your sinus node also needs to be paced?

Micra

by AgentX86 - 2019-12-21 21:55:38

I'd be very curious about the thought process that thought a Micra was good for an AV block.  Of course, the atria and ventricles are going to be dyssyncronous with only a single ventricle lead.  There is nothing to synchronize them.  That's the whole purpose of a "dual chamber" or dual lead pacemaker.  The lead in the right atrium senses the pulse and, after some preset time, it delivers the pulse to the ventricles, just as the AV/His/LBB/RBB do naturally.  Without the lead in the atrium, there is no way they top and the bottom can synchronize. 

Why in the world didn't they just implant a dual lead pacemaker in be done with it?

   -so confused.

I have that problem but it's intentional.  I have an intentional AV/His block (AV ablation) to keep the atrial flutter from propogating through to the ventricles.  I'm then paced in both ventricles so my atria are just fluttering away but the ventricles beat normally.  I sure wouldn't want this if there were any other way to get rid of the symptoms of Aflutter.

Answer

by SNORTINGDONKEY - 2019-12-21 22:04:07

Because radiation therapy affected my veins and they couldn't put the top lead in. 
 

Well..

by AgentX86 - 2019-12-21 22:55:21

That makes sense, anyway.  In fact it's the best reason I've read for a Micra yet. 

Dyssynchrony doesn't just eliinate the ~20% atrial "kick" but it actually worse than that.  The out-of-sync atria actually load the heart because both valves can be closed at the same time, and no blood is pumped.  Your problem runing is qute understandable.  I hope the new Micra goes into general use soon.

...

by SNORTINGDONKEY - 2019-12-21 23:22:19

It's been submitted to the FDA for approval. My doctor said February. 

Micra AV

by pbbrown7 - 2019-12-27 12:32:49

Medtronic is naming this new Micra, Micra AV. The first ventricle only was released in 2016 and named Micra TPS. This Micra AV is modified such that it can sense the atrial beat and then beat the ventricles at the right time. It was able to do this 94% of the time in clinical studies for patients in normal sinus rhythm in the atrial and complete heart block. The main concern is what to do when the battery runs out. Some thoughts are abandon it and place a second Micra AV. In testing they could place 3 but in a human trial of the Micra TPS they had a failure and needed to remove or replace the device. They couldn't find a good site for a second device so they retrieved it and placed a new one. Retrieval seems possible early on but the concern is what about after 10 years. If it can't be removed and a suitable site for a second can't be found then what? It might prove to be the better choice down the road but right now while it reduces risks due to no leads and no surgical pocket I am still way to concerned with getting this as I am only 40 and would need several. I plan to get the standard Medtronic PM and have surgery. Maybe down the road I can have the leads removed and move to something like this Micra AV. Who knows.