Danger of ventricular pacing in SSS with AV Block?

• by jds66
• 2012-07-18 04:07:50
• Checkups & Settings
• 2106 views
• 4 comments

Danger of ventricular pacing in SSS with AV Block?

I have had a mixed bag of feeling since receiving my PM on 3/29/12. I got the PM for SSS, and junctional rhythms, basically bradycardia. My heart during the night was going into the 30’s, with a pause as long as 3 seconds. During the day, I was in the 40-50 range mainly, with fatigue.

I never have passed out, before or since the PM.

What I have had is a variety of good and bad feelings- and many adjustments since 3/29, to try to combat the symptoms of being light headed and fatigued, none have totally eliminated all the problems.

Without getting into a long winded discussion, here are my results under the various settings I have encountered since 3/29.

History of Pacemaker Settings (Rate is Lower Rate)

Date Rate AS-VS AS-VP AP-VS AP-VP
3/29-4/3 60
4/3-4/9 70 35.0% 90.0%
4/9-4/20 60 12.0% 2.3% 48.0% 37.7%
4/20-5/7 40 63.4% 0.1% 35.7% 0.8%
5/7-5/9 40 38.5% 0.6% 52.9% 7.9%
5/9-6/4 40 63.8% 0.6% 33.4% 2.2%
6/4-7/17 50 28.8% 50.8%
7/17- 40


My major “problem”, according to my EP is that I am pacing the ventricle too much. He doesn’t exactly explain why that is bad, but I know from reading here that too much ventricle pacing in SSS can be bad for the heart.

I have found that when my lower rate is set higher, for me anything over 40 is high, I have an much higher occurrence of ventricle pacing.

My most recent visit to the EP, 7/17- I was considering having my lower rate raised to 60, because I felt well when I initially went to 50 bpm on 6/4. But, after around 6/21 three weeks or so after going up to 50, I was getting increasing pain in breathing, to the point that I would wake up at night gasping for air, which in turn raised my bp significantly. (and, no, sleep apnea is not an issue)

The SOB would stay with me during the day also, not to a debilitating point, but to where it hurt right between my shoulder blades to take a deep breath.

My EP hooked me up to the Medtronic machine 7/17 and immediately told me that I was in heart block. Then, just as quickly, the heart block was over. He turned my rate up, and sure enough, heart block came and went again.

He turned down my rate back to 40 (I had been at 50 for the previous six weeks and the ventricle pacing number is pretty high 28.8%), and the heart block went away again. I heard him mention later that it was Wenkebach block, which I believe is Type 1 block.

He tested my leads, as I thought maybe something had shifted. He said that they were conducting as they had previously.

He is totally baffled as to what is going on. He is not a novice EP, has been doing this for years and he said he has never seen a heart do what mine is doing. He said that the AV node is sometimes letting the signals through, sometimes not- and other times the ventricle is taking over the beating- regardless of that the pacer is telling it to do.

He said, “it is like your heart is just there, doing its own thing”. That he is so baffled by this leaves me a little concerned- but the one constant is that I know when my lower rate is set at 40- this ventricular pacing seems to happen a very small amount of time.

I can say I am noticing an improvement in the SOB after only one day- I am scheduled for an echocardiogram tomorrow, so maybe that will yield some results.

My Medtronic unit is all ready using the MVP(managed ventricular pacing) option, he thought that might help, but it was all ready enabled.

At this point, my EP is baffled- I am not educated in the heart enough to be able to diagnose this- I have certainly schooled myself on the Medtronic Revo enough to be able to suggest settings to my EP-

I don’t know exactly how to proceed- I thought I was seeing some improvement in symptoms for a few weeks after upping the lower rate up to 50, but the last 3 weeks, the SOB symptoms and now this ventricular pacing issue makes me think that my heart just does not like being pushed artificially above 50.

I asked my EP about possibly using the AAI mode(just atrial pacing, ventricle pacing off) only, his worry is that since there is the intermittent AV blocks, that without the ventricle lead firing off, I might pass out, which is possible, but I am thinking with a lower rate of 40, my ventricle naturally would fire off, as it did pre PM and prevent any passing out- which has still never happened prior to PM even.

Is it possible that my heart is fighting the PM?

And, is the excessive ventricular pacing with SSS and AV block hurting my heart?