AV pacing and tachy brady syndrome

PostOpPrincess, BSN, RN · Dec 13, 2009

I am not an expert in pacing (ask a Medtronic, St. Jude's, etc., rep when you see one around)...

but having been on a OH unit/Code Team..I've seen it done plenty of times.

I've done Atrial overriding with a manual atrial pacer for paroxysmal a-tach/SVT , and chemically/mechanically converted someone out of a ventricular dysrhythmia--the questions I would have would be--if this is WPW or a form of it--what kind of tachy is it? Is it a an AICD combo? I'm going to assume since you said the patient is on beta-blockers, do the runs last a long time or is it a few seconds of PSVT?

Has the patient considered having an ablation to find the aberrant pathways? Has the patient tried new combos of bbs?

Perhaps someone who works in a cath lab with ablation therapies can answer this a lot better.

Love to know more info myself.....

RedCell · Dec 13, 2009

I work in a telemetry unit and have a question. Another nurse and I have come up with some ideas about the answer, but we just aren't sure.

We have a patient that has tachy brady syndrome. She has an AV pacemaker and is usually paced in the 80s. She will have intermittant tachycardia in the 130s. We know that she is receiving beta blockers, but we aren't sure why the AV pacemaker doesn't control for the tachy rate as well. So why doesn't the pacemaker control for both the brady and the tachy?

Is the source of the tachycardia pacemaker mediated? Is it an AICD/pacer or just a pacer? Does the patient have a history of a native reentrant dysrhythmia? Also, does the pacemaker have tachyarrhythmia detection capabilities? Finally, when was it last interrogated?

From what you have stated, it sounds like the dude's pacemaker is functioning fine. Pacers without tachyarrhythmia detection that are DDD sensing/pacing will fire if the HR drops below a certain preset rate, or if it senses an atrial spike without a QRS following. Although back in the day pacemaker induced tachycardia was more of a problem, it has become much less of an issue in the present era of EP technology.

questionsforall · Dec 13, 2009

This syndrome is also know as sick sinus syndrom. The sinus is not regulating correctly. The pacemaker is only in place for the bradycardia in these patients. The problem before the pacemaker is that they could not control the tachycardia with a beta blocker because the patient could become bradycardic. So they put in a pacemaker and load them with a beta blocker, so that they can control the tachycardia without causing bradycardia.

ippagoggy · Dec 13, 2009

This syndrome is also know as sick sinus syndrom. The sinus is not regulating correctly. The pacemaker is only in place for the bradycardia in these patients. The problem before the pacemaker is that they could not control the tachycardia with a beta blocker because the patient could become bradycardic. So they put in a pacemaker and load them with a beta blocker, so that they can control the tachycardia without causing bradycardia.

Thank you so much! I should've included more information in the first post (ie: that she had sick sinus syndrome and AICD combo etc). This is what we were thinking, but we weren't sure. Thanks again for all of the responses!

PostOpPrincess, BSN, RN · Dec 13, 2009

Is the source of the tachycardia pacemaker mediated? Is it an AICD/pacer or just a pacer? Does the patient have a history of a native reentrant dysrhythmia? Also, does the pacemaker have tachyarrhythmia detection capabilities? Finally, when was it last interrogated?
From what you have stated, it sounds like the dude's pacemaker is functioning fine. Pacers without tachyarrhythmia detection that are DDD sensing/pacing will fire if the HR drops below a certain preset rate, or if it senses an atrial spike without a QRS following. Although back in the day pacemaker induced tachycardia was more of a problem, it has become much less of an issue in the present era of EP technology.

I think she wants to know why the settings (DDD) won't override PSVT. I've never known anything to override PSVT except by another person's intervention.

Virgo_RN, BSN, RN · Dec 13, 2009

The AICDs will often have a set rate for a set duration before shocking. For example, the rate must be >180 for >30 seconds before the device will deliver a shock. If the person has bursts that either don't exceed the set rate, or terminate before the set duration, then the AICD will not fire.

PostOpPrincess, BSN, RN · Dec 13, 2009

The AICDs will often have a set rate for a set duration before shocking. For example, the rate must be >180 for >30 seconds before the device will deliver a shock. If the person has bursts that either don't exceed the set rate, or terminate before the set duration, then the AICD will not fire.

Thank you!

RedCell · Dec 14, 2009

i think she wants to know why the settings (ddd) won't override psvt. i've never known anything to override psvt except by another person's intervention.

first of all, i would like to say that i enjoy reading your posts as they are much more stimulating than the whining/complaining/cultural feel good type discussions that are typically seen on this website. however, i have never heard of psvt occurring at a rate in the 130's as the op originally stated. that just does not make any sense. second of all, i do not mean to undermine your knowledge of pacing capabilities, however present day pacers have the ability of employing tachyarrhythmia modes that override the intrinsic rhythm and reduce heart rate. there are a cuppla different methods for accomplishing this. one example, a ddd pacer with tachyarrhythmic settings will often switch to a vdi mode to overdrive an atrial tachyarrhythmia once a predetermined amount of atrial impulses are detected by the device's programmed settings. i think this stuff has been around now for about 10 or 12 years.

here is an older study published in 01' looking at the efficacy of terminating pat with a ddd+ pacer: http://131.188.28.126/links/200106040269.pdf

i agree that drugs, defibrillation and/or cardioversion have been the standard decision in the past, but times are a changing.

PostOpPrincess, BSN, RN · Dec 14, 2009

first of all, i would like to say that i enjoy reading your posts as they are much more stimulating than the whining/complaining/cultural feel good type discussions that are typically seen on this website. however, i have never heard of psvt occurring at a rate in the 130's as the op originally stated. that just does not make any sense. second of all, i do not mean to undermine your knowledge of pacing capabilities, however present day pacers have the ability of employing tachyarrhythmia modes that override the intrinsic rhythm and reduce heart rate. there are a cuppla different methods for accomplishing this. one example, a ddd pacer with tachyarrhythmic settings will often switch to a vdi mode to overdrive an atrial tachyarrhythmia once a predetermined amount of atrial impulses are detected by the device's programmed settings. i think this stuff has been around now for about 10 or 12 years.
here is an older study published in 01' looking at the efficacy of terminating pat with a ddd+ pacer: http://131.188.28.126/links/200106040269.pdf
i agree that drugs, defibrillation and/or cardioversion have been the standard decision in the past, but times are a changing.

thanks for the info--it's been awhile, i admit--i'm out of that area now so i would have to immerse myself in them again. i never dealt with perm settings either--as i usually overrode with the standby pacer for ohs. no undermining at all as my original post was wondering it myself...

and thanks for the "posts" compliments--i've been accused of being negative and "bitter"--but the feel good posts are just not in me as i find them almost symptomatic of "lala fantasy world" that i know doesn't exist. i also find them extremely degrading to my intellect and unfortunately, i do not feel i need to be touchy feely to know that i am a good rn. that kind of stuff makes me "puke a little in my mouth."

hehe....