Biventricular Pacemakers

One of our EP docs has been doing a roaring business in bivent pacers lately.  Between upgrades to existing pacemakers and new bivents we’ve been seeing these frequently.  On top of that, when we moved, our telemetry provider upgraded our system and software so we could actually see bivent pacing.  I figured that a quick primer on bivents was in order.

What is a biventricular pacemaker anyway?  It is what it says.  There is a lead in each ventricle, pacing each ventricle.  Historically, pacemakers have been one sided only, usually the right ventricle (RV) and/or right atrium (RA) due to ease of access.  You pop into the venous system, float a wire into the right side and you’re good to go.  The difficulty ramped up in reaching the left ventricle (LV) generally, the veins of the coronary sinus are harder to access and of a smaller caliber.  Thanks to advances in catheter size and mobility, this has gotten easier.

But why do this?  In heart failure, espcially dilated cardiomypoathy, the dilation of the heart makes the ventricles, well, floppy.  They get big and stretched out and consequently the condution system gets stretched out as well.  What begins to happen is that the RV and LV start beating out of time (or asynchronously), which in the end makes the heart work harder to achieve the output needed.  The harder workig heart stretches more, which make it work harder to maintain output and on and on down the spiral.  Cardiac resynchronization therapy (CRT) with the use of bivent pacing enables the heart to start beating in time once gain.

I know that I’ve way oversimplified this, but I’m going for core concepts here.  But talking about CRT allows me to post up some great strips that I’ve picked up to demonstrate visually what is happening.

click for largerLooking closely, you notice a couple of things.  This is both a bivent and a dual chamber pacer.  Notice the spikes before the P wave and then the double spikes leading into the QRS complex.  We’re able to see both the RV and LV leads firing.  So instead of having only 1 lead firing in the RV and having the conduction impulse cross via cell-to-cell contact, each side of the heart is being paced, thereby getting better contractility and a better ejection fraction (EF).

Here’s the same patient:

click for largerI changed the tracing speed to 50mm/s to better illustrate the 2 separate ventricular spikes.

In many cases, this is coupled with a defibrillator (CRT-D) for the prevention of sudden cardiac death due to ventricular arrhythmias that folks with severe heart failure can be prone to.  And it is proven to work.  In the MADIT-CRT trials, there was a “29% reduction in death or heart failure interventions when comapred to traditional implated cardioverter defibrillators.”  (h/t Dr. Wes)

Yes, there are risks, there are patients this doesn’t work for and the cost is pretty steep (I’ve heard in the range of $45,000 for the device alone…) but it appears to do what it is intended to do.

Here’s a couple of resources for some in-depth information:

Cleveland Clinc: Biventricular Pacemaker

About.com: Cardiac Resynchronization Therapy

WebMD: Cardiac Resynchronization Therapy

Summer Medblog Smackdown

In booming announcer voice…

“Ladies and gentleman, boys and girls children of all ages…welcome to the Interwebs Arena for our main event of the  Summer…”

“Fighting out of the Doctor’s Corner wearing the red trunks, the contender from a big hospital somewhere in America.  With a record of 200,000 and 0, years and years of residency training, thousands of sidebar ads and an ego a mile wide, Happy “I’m a Medical Doctor and have my own way of running a code” Hospitalist! …”

“And out of the Nurse’s Corner, wearing the blue trunks, the challenger from a big ER somewhere else in America.  With a record of a million saves, years of being at the front lines of American health care, a chip on her shoulder and Dr. Bloody Gloves in her corner, Nurse “The Snarkinator, can’t believe Happy runs a Code like this” K! …..”

crowd goes wild…

“Let’s get ready to ruuuuuuuumble…..!”

referee…

“OK you two, let’s have a clean fight.  No low blows, no crayzee talk…oh whatever, just come out swinging.”

announcer

Happy and Nurse K are at it again.  Sit back and enjoy the show.

Not going to say who’s right, who’s wrong (although Nurse K is right dude, either wake the patient up for fucks sake, hello, sternal rub ’em! or pull the cord for the code team), but it sure is turning out to be a real smackdown.  I mean between Happy’s smug aloofness and K’s snark attack, you’ve got a real read on your hands.

Happy’s Post: Michael Jackson May Have Died From Fibromyalgia

Nurse K’s Rebuttal: How to resuscitate a patient Happy-style

Happy’s Attempt to hide the fact he got pwned: Is It Reasonable to Stock Every Room With Emergency Resuscitation Supplies

Would you two just get a room or something…

Edit: K just posted up a rebuttal to Happy’s rebuttal (a double butt-al?)  Face it bro, you’re getting pwned.  Throw the towel.

Customer Service Surveys

Instead of the dreaded Press-Ganey, we use HCAHPS to track our patient satisfaction scores.  This then dumps to the Hospital Compare website that showcases how poorly we do.  Or at least how we are percieved by our patients.

In a staff meeting  they went over some of our latest scores and this time provided comments along with the scores.  My floor, well, according to the surveys, is pretty much the worst in the hospital and our sister floor is a little better, but not much.  The best scores came from the folks who do mostly stuff that people want to be in the hospital for.  Things like childbirth and total joint replacements.  The floors that do a roaring trade in people who do not want to be in house had the worst scores across the board.  This tells me several things.  First, the whole idea of rating is bunk.  Second, basing a rating on a subjective survey is bunk.  Third, unadjusted scores for patient population (taking into account when tallying pain control with the number of drug addicts and chronic paineurs we have) is bunk.  And finally, no cross-referencing the mortality rates with satisfaction is bunk.

Granted, I’m biased.  I think that the care we provide is the best possible for the situation.  But, we’re not perfect and that’s what it seems the mob wants us to be.  They want to be pain-free.  It’s nice, but after giving you the amount of narcotics to kill an elephant and your pain is still a 10/10, nothing, I repeat, nothing is going to make you pain-free.  They want it to be quiet at night.  Sorry we have some double rooms, but the alternative is less rooms so that you stay in the ED will be even longer (another complaint).  And unfortunately, people get sick and admitted in the middle of the night and as quiet as we may try to be, attempting to get a history out of an 80 year old dude who’s deaf as a doorknob is not going to be conducive to your sleep (another complaint).

Now having had crappy hospital experiences with my family, I am sympathetic to the need to control pain, keep things quiet, let you sleep and all the other things that we do wrong.  Believe me, I understand, I do.  I try to make the stay as pleasant as I can, but sometimes, I just can’t.  I need to check you vital signs every 4 hours to ensure that you’re not dying quietly on me.  We have to draw blood to ensure that everything is progressing the way we hope it should.  Sometimes you have to have a roommate, but it is better than spending the night in the ED because there are no beds upstairs.  So many of the things we do “wrong” is things taht need to be done in order to heal.  Guess many people just don’t get that part of the equation.

This though sums the entire thing up for me, it should “be free of charge.”

Question to the Experts

Awhile ago I’m sitting charting when the tele tech comes out of his cubby and says rather excitedly, “93’s rate dropped to 27 and is staying there!”  I pop up, walk over to the room and and see my patient sitting at the side of the bed with a look that says, “What do you want?”

“Do you feel OK?” I ask as I’m slapping a BP cuff around his arm.

“Feel fine.”

“Not dizzy, light-headed?”  I press.

“Nope, nothings changed from when you were here last.”  he says as the BP pops up 144/72.

“Your heart rate dipped into the 20’s and hung there for awhile, that’s all.”  I reply.

Here’s the funny thing though:  he had been doing this for days.  No problems with the low pulse at all.  Peeing fine.  No light-headedness, dizziness, auras or any other weird lack-of-perfusing the brain problems.  Only problem was when he moved about too much, he turned a lovely shade of eggplant purple.

Telemetry was showingwhat appeared to be a slow atrial fibrillation, but with his size, it would not have surprised me it if was a combination of junctional and ventricular escape rather than the a-fib due to the morphology of the QRS complexes.  Even with that in mind though, it could have been a-fib with a bundle branch block.  Then by luck, the morning before he was going to get a pacemaker the tele tech and I were chatting and examining his rhythm when we were able to get this shot.

click for largerIt starts with a PVC, then a sinus beat and another PVC.  Then it starts to get funky.  The deflection of the QRS complexes shift in every lead except the V-Lead, flipping opposite from what they had been doing.  There wasn’t slowing of the rate that could be coupled to this flip as he had gone lower several times during the night and his strips hadn’t changed like this.  Looking back through, we noticed that he had been doing this all along, but had never captured it on paper.

So why question becomes:  what the hell is going on here?  Am I looking at a junctional/ventricular escape type of rhythm?  Or an intermittent right/left bundle?  And what could be causing this transient shift in axis, especially with no complaints from the patient?

And for what it’s worth, he got a pacer and looked much, much better the next day.  But I’m still baffled.  Any help?

Kind of weird

It’s kind of weird to see a co-worker looking at your blog while at work and having no clue that the author is sitting less than ten feet away.  Or at least they didn’t say anything about it..

Oh yeah, it looks like Mr. Black Cloud is back.

Why do patients try to die right before shift change?  Don’t they know the last thing I want to do before I go home is send them to the Unit.  Well, I wanted to send this guy to the Unit, he was Sick (notice capital S?).   But why at all times to crump than at 6am?  It must be my luck.