Exercise test

DDD to DDI mode change

by AgentX86 - 2020-11-23 23:10:32

I'm not sure DDD to DDI is a mode switch at all.  The third 'D' means it's dual mode DDI or DDT, whatever's needed.  It's not really a switch, per se. A switch would be from DDD to VVI (or VVO) after atrial tachycardia was detected, for instance.

It sounds like you hit your maximum rate and it switched to 2:1 conduction mode to limit your ventricular rate.  If this is the problem (it's hard to know with this little information), your EP set this intentionally.  If this is the case, a 90bpm heart rate suggests that your atrial rate went to 180bpm.

DDI Mode

by PacedNRunning - 2020-11-24 01:48:21

DDI mode is a mode that will inhibit pacing if your ventricles are able to beat on their own.  So if it senses a ventricular beat or atrial beat it will withhold pacing.  The "I" means inhibited as a response to sensed beats. My guess is they need to increase the rate for your upper rate tracking for the switch.  There are AT/AF mode switches. They may need to increase it so you can exceed it without it switching. I hope that makes sense.  

Mode Switch might be key

by Gemita - 2020-11-24 03:46:07

Hi Savannah, I am sorry you are still struggling and haven’t yet had an EP study/ablation.  Not the best time to get anything done unfortunately is it.  

From your comments I somehow feel this is a mode switching sensitivity problem and that mode switching is being activated too many times and causing instability. This is something that I am also experiencing.  By adjusting other settings (increase upper tracking rate) so that mode switching is not activated so frequently might just help.  I am hoping so anyway.  

I think too as we both know, going in and out of arrhythmias is certainly activating our mode switching (so that the fast atrial rates are not tracked by the ventricles), on a frequent basis but this comes at a cost and increases our symptoms.  I had thousands of mode switches reported for AT/AFib at my last pacemaker check.  I was shocked, but not surprised.   When your arrhythmias are hopefully stabilised through an ablation, you and your pacemaker should have an easier time!  I am still trying to work with my settings but maybe I need to go down the ablation route too?

https://www.medtronicacademy.com/features/mode-switch-feature

I have attached a Medtronic mode switch link above for further reading in case it helps?  While you wait for your ablation please try to push for a settings change immediately otherwise Christmas will soon be here and nothing will be done.  Good luck Savannah and hope the little one is behaving himself and looking after his Mummy.  You need all the help you can get

I think its a safety feature

by Savannah55 - 2020-11-24 14:16:13

From researching I think switching from DDD to DDI is an automatic safety feature when experiencing an atrial tachyarrythmia- it stops tracking the atria to prevent lethal ventricle tachycardia.

My upper tracking is set at 150bpm which is why I am confused, as my heartrate always maxes out at around 125 when I'm doing exercise! 

Gemita thank you as always. I really do not think anything will be done this side of Christmas. I seriously do hope an ablation fixes the problem because I'm so fed up off feeling so rubbish. I am struggling with my weight at the moment but cannot work out as it floors me. 

Another odd thing is that only my pacemaker picks up these AT episodes- they cannot see them on the 12 lead ECG.