This 'n That

New EP feels I'd do better with a PM/ICD device, rather than the 3-lead Medtronic device I currently own. I understand the ICD would come into play if a dangerous tachycardia set in. How does one define a "dangerous" tachycardia? (In early 2012, prior to my PM implant, the folks at TCAI were not concerned with my NSR pulse of 125 for 2+ months) I just went through a 118 pulse for 15 minutes before resuming my 100% paced 84 pulse. A couple EMS folks in the past have stated my PM will allow a short run of tachycardia, then increase the pulse to a number higher than the tachy event and eventually drive the pulse back down to the desired number (84 in my case). I'm not sure I believe that theory since I've found nothing on the Medtronic site to corroborate that claim. Any comments, gang?

3 Comments

Medtronic site

by Theknotguy - 2014-11-28 10:11:33

Know what you mean about the Medtronic site. I have a Medtronic PM and am very happy with it. However, for some reason, when I go on the Medtronic site I usually end up in a dead end. Fortunately members on this forum have been able to penetrate into the deep dark recesses and locate the information. Hopefully they will read your post and give you a direct address.

I'll give you a link which may answer your question.

http://www.medtronicfeatures.com/browse-features/all/CDF_DF_MODE-SWITCH

I've been very happy with my Medtronic. I had the APP function (Atrial Preference Pacing) turned on in May of this year and have noticed a difference for the better in my afib sessions. Another member pointed out APP won't initiate a counter beat to my afib but it sure feels that way. In any case and regardless of how it happened there has been a decrease in the number of afib sessions I've had since APP has been turned on. There wasn't an instant change with APP turned on but there was a difference over a six month period.

Medtronic did a survey and indicated APP did make a difference for people who have APP turned on. However the survey was done my Medtronics. I also don't know if the results were only given to doctors.

I hope your Medtronic PM performs as well for you as it has for me. My best wishes go out for you.

ICD

by golden_snitch - 2014-11-29 11:11:57

Hi Dave,

an ICD has special algorithms to detect ventricular tachycardias, and to differentiate between atrial and ventricular tachycardia. It can analyze the ECG and an arrhythmia originating in the ventricles looks much different than one that originates in the atria.

Sometimes single chamber ICDs, that have one lead in the right ventricle only, have problems to clearly differentiate between fast rates caused by atrial fibrillation and fast rates coming from the ventricles, but that's because there is no lead in the atrium allowing the device to "see" more clearly. You have a CRT device already (bi-ventricular pacemaker), with one lead in the right atrium, so this should not be a problem in your case.

Also, ICD have programming options with regards to the different therapies it can deliver. Ever since the so called MADIT-RIT trial most ICD are programmed not to shock at heart rates lower than 200bpm. Also, they are programmed to wait a little longer till they deliver a shock. In the trial different settings were tested, and it was shown that patients in whom programming isn't that "aggressive" (e.g. shocking at comparatively slow rates) have much better survival rates.

What has also changed is that the first shock is delivered using the max. energy; years ago it shocked, for instance, with 20 Joule first, then 25, then 30, leading to many patients receiving several shocks when one shock with max. energy would have been sufficient.

Before an ICD shocks it can deliver a therapy called "anti-tachycardia pacing" (ATP): When the device detects a ventricular tachycardia, it starts pacing the ventricle at a rate that is a bit higher than the tachycardia, and then it slowly decreases that pacing rate. I know several ICD patients who never got shocked, ATP always stopped their ventricular arrhythmias before a shock was necessary.

Hope this helps a bit.

Inga

Opinion from my new EP

by Dave H - 2014-12-01 12:12:51


There is no proven effect of atrial preference pacing. There is also no proven benefit of anti-tachycardia pacing (ATP). While I am suspicious that that former may make AFIB worse but the latter cannot hurt. If your device does have ATP, it doesn't hurt to program it on. I would not program preferential pacing on for fear of more AF (theoretically). I'll check with Melanie at the device clinic to confirm that this is programmable feature for your device. You may also make an appointment directly to do so.

You know you're wired when...

You have rhythm.

Member Quotes

I’m healthy as a horse because of the pacemaker.