1st degree Heart Block

[Konopka1955]

Hi, I'm so thrilled to have gotten to post a question.



First of all I had OHS for MV - I had a replacement - I went into full heart block after my surgery - they reprogrammed my ICD from the AAI mode to the VVI mode and I've been fine.  



1.  Since then I saw my surgeon again and my ekg - said I was in 1st degree heart block - which is better than full block..  Right??



2. Now I think I may want to try the DDD mode on my ICD program - but had I been in full block - this mode would pace my right ventricle - constantly - but now that I'm in 1st degree block - do you think a DDD mode could cause me to become pacer dependent?



3. Can you explain - in layman's terms about this AAI mode and VVI mode and the DDD mode?  I don't quite understand it all.  But a runner friend of mine told me that the DDD mode is a much 'runner' friendly program.  She has an ICD and runs.  



4. I want the best ICD running program and I'm not sure what to ask for - do you know which is better for running?  AAI, VVI, or DDD?



5. Do most patients who go into full heart block (from surgery) come out of it - stay out of it?  Or perhaps like me it lessens to 1st degree block and you come out of that later.  Or does it usually progress to 2nd degree?



I have an ICD for ventricular tachys'  -  previous MI - but MV replacement was done due to rheumatic fever as a baby.



6. Do you know where I can learn more about 1st degree Heart Block and how long it lasts and if it progresses?



Thank You so very much for all you assistance.  :-)

Best Wishes

Konopka19

[Cleveland Clinic]

1) 1. Since then I saw my surgeon again and my ekg - said I was in 1st degree heart block - which is better than full block.. Right??



It is common for heart block after surgery.  Most of the time you are using your own conduction system from atria to ventricles its better. If you are in 1st degree block and are able to conduct at higher heart rates you may not need your pacer.



2) Now I think I may want to try the DDD mode on my ICD program - but had I been in full block - this mode would pace my right ventricle - constantly - but now that I'm in 1st degree block - do you think a DDD mode could cause me to become pacer dependent?)



No. In fact you could use DDD to pace people in complete heart block. To use DDD you need an atrial lead, which a standard ICD does not have.  If you are in 1st degree block, and able to use your own conduction system, there would be no need for DDD or VVI pacing, and the pacer could function as a back up.



4) 4. I want the best ICD running program and I'm not sure what to ask for - do you know which is better for running? AAI, VVI, or DDD?

  

Generally a DDD pacer would be best. There are other factors such as rate responsiveness programming that also play a role.



5). Do most patients who go into full heart block (from surgery) come out of it - stay out of it? Or perhaps like me it lessens to 1st degree block and you come out of that later. Or does it usually progress to 2nd degree?



You most likely have a higher risk than the general population for heart block later in life. However, I would imiaging this risk is not that great.



6) Do you know where I can learn more about 1st degree Heart Block and how long it lasts and if it progresses?



For most 1st degree block is a relatively benign rhythm and fairly common. It is important to keep in mind when dosing some drugs, but most often doesnt require intervention. Again, if you are in 1st degree block and relatively asymptomatic, i wouldnt put too much thought into your pacer or modes to try to pace alternatively.



Your EP can interrogate your device at each visit to see how much you are getting paced above your normal rhythm.



good luck

[Mickie]

I'm not sure about all of your questions, but I may be able to help wiht one. The first of the three to four letter in the pacemaker/ICD program code stands for which chambers are paced. If the first letter is "A" then the atria can be paced, if it is "V" then the ventricles can be paced, and if it is "D" then both the atria and ventricles can be paced. The second letter represents which chambers are sensed. The third letter is usually an "I" meaning inhibited, or "T" meaning tracking, or "D" meaning inhibited and tracking. So...AAI paces your atria at a set rate as long as the device is sensing that the atria need to be paced (your own heart rate is below the programmed low rate), if it senses your atrial rate is above the set lower limit, it will inhibit it's output and stop pacing. In VVI, it's the same but in the ventricles. In DDD, while in full/third degree/complete heart block, the device senses how fast the atria are beating, and if they are beating faster then the lower limit, the device paces the ventricles however fast the atria are beating(this is what tracking is). If the atrial rate is below the lower limit, the device will pace both the atria and ventricles at the set lower limit. If you came out of complete heart block and your atrial and ventricular rates were fine, the device would inhibit output and not do anything but sense. The good thing about DDD is that the atria and ventricular contractions are coordinated occuring at the same rate per minute, unlike in VVI. AAI leads to coordinated atria and ventricles, but can't be used in complete heart block. This is probably more then you were asking, but I hope it helps a little. Maybe the doctor can say it in simpler terms? Good luck,

Mickie

[DottyCece]

Hi,



I had a DDDR pacemaker which means that I had sensing and pacing in both the atria and ventricle.  WIth activity, my pacemaker went up to a rate of 130 which is what you would want for running.  After my redo open heart surgery two months ago(mitral valve replacement redo), my atrial lead was damaged and did not work any longer so I was reprogramed to a VVIR pacer.  Last week I had a AV nodal ablation and am now pacer dependent with a VVIR pacemaker.  In cardiac rehab I have been able to increase my rates from 80 to 128 to 130 on the threadmill and tolerated it fairly well.  The problem with not having a DDDR pacemaker is that I will not have what is called the atrial kick which helps to increase the cardiac output (increase in EF).  That can be a problem for some people.  So for me, they are loading me back on amiodarone and then will cardiovert my atrial fib once again in two months and if it is sinus rhyhtm, they will revise the atrial lead and I will once again have a DDDR pacemaker.  



I never had a heart block but rather tachybradyarrhythmias secondary to sinus node dysfunction.  So, it is questionable whether I will ever have AV sequential pacing which is what I want more than anything.  Keep asking your electrophysiologist questions.  The technology is evolving and their approaches are ever changing.  I am not giving up because I think there will be a better solution in time.  For the time being, I have to cope with what I have.