Rate response question

how it works`

by Tracey_E - 2018-12-18 17:52:00

If you are in av block then your sinus node in the atria works normally, you need the pacer in the ventricles to make sure the ventricles stay in sync with the atria. The pacer can only go up to the upper limit so if your atria is doing 170 but your upper limit is 160, you will still be pacing at 160 but the heart will be out of sync and it won't feel good. As soon as your rate comes under 160, you'll feel normal again. So, the answer to when does it start pacing is it never stops pacing. The answer to when you feel good again is however long it takes your atrial rate to come down under the upper limit. 

rate response

by Tracey_E - 2018-12-18 17:53:34

And none of that has anything to do with rate response. Rate response is when the sinus rate doesn't go up adequately on exertion, then the pacer steps in and increases our rate. That's atrial pacing.  If you have av block you may not even have rate response turned on because you don't need it. 

Similar to the lower limit?

by benne81 - 2018-12-19 17:44:49

So is this similar to the lower limit? How does that work if the lower limit is set to 60?

lower limit

by Tracey_E - 2018-12-19 18:32:47

Lower limit is for the atrial lead, how low your sinus rate will get before it kicks in with atrial pacing. If it's set at 60, that means it won't let you go a second without a beat.If you have av block and a normal sinus rate, you probably don't use this very often so it doesn't much matter where the lower limit is set. When our pulse is too low because we are in av block, it's because the ventricles aren't keeping up with the atria, not because our atrial rate dipped too low. 

Rate response isn't upper or lower limit, it's when the pacer senses movement and the atrial rate doesn't go up, then it kicks in and makes our rate go up.

Rate Response

by Selwyn - 2018-12-20 07:37:00

The onset and offset of pace maker rate response can be set ( and adjusted).

I have a fast onset and a moderate offset.

The result is that when I jump into a swimming pool and wave my arms around the PM starts quickly to increase my heart rate. At the end of my swim it take about a minute for the heart rate to drop.  

My upper limit for pacing is 115 bpm. Swimming produces a HR of 120 bpm at the end of a session as I check my pulse rate. 

You can repeatedly, rapidly,  tap your PM with a finger and see how the rate response performs if you don't mind getting palpitations- a bit like revving an engine before letting out the clutch for a sprint start!