AV Delay

Has anyone had their settings changed for their AV Delay and Have you felt a difference? What is AV Delay and how can it make you feel worse or better?

4 Comments

AV Delay

by Carol - 2007-11-26 03:11:47

Hi! I have had my AV delay adjusted to the max by the PM technician. She even had to check with the Doctor to make sure it was OK with him to set it where it's currently at. I don't know all the particulars but what I can tell you, is that I was having trouble with "feeling" the PM kick in . On the day I went in and had it adjusted, I was having a particularly rough day with tachycardia and what I believe were PACs/PVCs-anyway sure felt like lts of skipped beats and pauses. I think by increasing the delay this gives the heart a little more time to kick in on its own before the PM takes over to initiate the heartbeat. I have felt pretty much OK since the adjustment, I don't notice the PM working, but I still get runs of those premature beats and I know that the PM can't fix that. Sorry I don't know the technical aspect of your question....mostly just know I've had it done. Best wishes, Carol

AV Delay

by SMITTY - 2007-11-26 10:11:21

Hi JL,

Your questions of "What is AV Delay and how can it make you feel worse or better?" are interesting and are about something we frequently hear about but I have never been able to get a clear cut answer I can understand. However, after reading about 25 or 30 articles on the subject, I think, and I repeat, I think, a proper AV adjustment is necessary to have the chambers of our heart in sync for them to function at the optimum.

Now for an answer to your questions, read the following paragraph. Before you think something ugly about me, if you understand what is said in that paragraph good, but if you don't welcome to my crowd. Frankly, I thought it was something that would make any Philadelphia lawyer proud. I'm sure it says something, I just have no idea what it is really saying.

"A cardiac pacemaker has an algorithm for dynamic overdrive of a patient's atria in order to suppress atrial tachyarrhythmias. The device further has circuitry for adapting the AV-delay during dynamic overdrive of the atria to a value adapted to the patient's needs."

Now, the following paragraph does a little better.

The chambers of the heart contract and pump blood with the directions conducted by the electrical system of the heart. The electrical system starts usually at the sino-atrial node (SA node), a cluster of specialized cells. The SA node works as a pacemaker and produces electrical impulses at regular intervals, setting the pace for the heartbeat. Each electrical impulse spreads throughout the atria (upper chamber of the heart) causing the heart to contract and pump blood into the ventricles (lower chambers of the heart). Beginning at the atria, the electrical impulse reaches the atrio-ventricular node (AV node).

The AV node then slows each electrical impulse prior to going to the ventricles. This slower impulse reaches the ventricles through a conduction pathway (made of specialized muscle fibers). This pathway divides into a network of smaller fibers, distributing the impulse throughout both the lower entricles allowing them to contract and pump blood.

And this one may add even more.

A dual chamber pacemaker system, having atrial sense means for sensing signals from a patient's atrium, ventricular sense means for sensing ventricular signals from a patient, ventricular pace means for generating and delivering ventricular pacing pulses to said patient's right ventricle, AV means for setting and timing out an AV escape interval from the occurrence of a sensed atrial signal, and sync control means for controlling delivery of a ventricular pacing pulse at the time out of a said AV escape interval in the absence of a sensed ventricular signal, comprising scan means for controlling said AV means to vary said AV escape interval through successive values thereof,

I think I have a little better idea of what is important about the AV settings now. I did go back and look at my checkup reports and my settings have not been changed from their original 250 ms for both the paced and sensed settings. I did notice that the Rate Adaptive setting are off and that the Search AV was increased from Off to >60 ms about 2 years ago. What those changes meant to me, I have no idea.

With all that said, I'll now join you in waiting to see if someone will give us clear answers to your questions.

Good luck,

Smitty

AV Delay

by ElectricFrank - 2007-11-27 07:11:24

Good one, Smtty! Maybe a simple explanation would be that in the normal heart there is a delay between the contraction of the atrium and the ventricle. This is due to the time it takes for the timing signal to travel down those tricky bundles to the ventricles. Ideally it gets there just as the ventricles are nicely full of blood and ready to contract. I'm not sure we have any idea how the heart knows this optimum timing. When we replace a broken bundle (block) with a pacemaker it works best if the timing is near optimum. My guess is that as long as we have a good heart other than the block it will adapt to any reasonable timing. With things like congestive heart failure we need everything we get so it becomes more important. I also suspect that like a lot of the settings, we have a subtle feeling that all is well when the timing is optimum, but the doc's can't measure our subtle senses so it doesn't mean anything to them.
So I started out to say it simply!!! Check out Smitty's and then mine and chose whichever one works for you.

gest,

frank

Fixed

by JLTREBEL23 - 2009-03-16 08:03:09

Ok guys I forgot to post a comment on this thread about my cardiologist finally adjusting my pacemaker settings back to their original settings! what an amazing improvement. but now more than a year has passed and I have felt alot better but I dont have the explosiveness feel of energy that I had when I first got my PM, I had my check back in january and all the settings are still the same as when I had it first implanted. I am really confused because now my average resting rate is a little higher than before.. now about 68 BPM and before about 61.. I have my pacemaker for bradycardia and my lower limit is 60 bpm. I also notice that my blood pressure is also a little higher ar avg 128/78, before it was 121/75 or lower. My point here is that when I used to exercise I felt my heart beat and energy in my body a great feeling, now when I am running I have to check my pulse because I dont feel that rush like before, when I am running around playing basketball I dont have the energy I used to have, I feel my pulse increasing and decreasing but again I feel weakish. I also have this weird feeling of my head and face feeling really hot when I get nervous before I used to feel my heart race and I would feel nervous but now I just feel something hot rush to my head and it feels really weird. Had blood work done, echo, ekg and everything is fine. I am confused about what this might be.. this has been going on for months! I am getting frustrated. Any suggestions would help. Thank you!

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