Stents for Mr. Floppy?

UPDATE 1-Medtronic to study stent in erectile dysfunction | Stocks | Reuters.

The study is intended for men who have not responded well to PDE5 inhibitors such as Viagra, Cialis and Levitra.

I figured that was just Nature’s way of saying, “Throw in the towel Rock!”

I can see the PMH now…

65 y/o male, history of coronary artery disease with coronary stents x3 and pelvic stents x2, hyperlipidemia, hypertension, diabetes, erectile dysfunction (resolved)…

or answers on the MRI checklist…

Uh, yeah, I got them stent thingies in my hips or something ’cause I couldn’t get it up no more and Vigara didn’t work…

I mean, really, let’s handle the hard, err..difficult topics in medicine: depression, hair loss and ED.  Got to have your priorities in the right place!

h/t to Dr. Wes

The Intensive Art: Linky Love

Nurse Sean, of whom evidently rumors of his demise were in fact exaggerated, has re-emerged, new site, new look and new stories.  Only issue is that he nuked the old site so folks looking for him will be just a little lost.  Go see his new site: The Intensive Art

Plus the new name is so fitting…it’s near perfect!

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.

Looking 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:

I 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

Neurosurgical Set From Early 19th Century | bored-bored.com

Neurosurgical Set From Early 19th Century | bored-bored.com.

Too cool.  Glad we’ve moved beyond this, kind of.  What passed for medicine in the 19th century really seemd to be more like butchery and until the realization of germ theory and infection control, odds were pretty grim.  Not to mention lack of anesthesia!

Issues

I was listening to music on my laptop the other night when it went all “fizzy” and strange.  Then it went dark.  Not good. 

I rebooted and everything seemed to be OK, then it went dark again.  Now I can’t get it to reboot or do anything.  Not good.

Luckily, all of my blog stuff is in the clouds and I just backed up the important stuff not too long ago so all is not yet lost.  Now I get to try to figure what is going wrong.  And I ain’t happy about it.  Posting will probably be a bit more sporadic than normal (not that I’ve been prolific lately anyway), but stick around, I’ll be back to myself soon enough.

EKG of the Week #1

Pretty classic example of failure to sense and failure to capture.

As you can see, the pacer is firing but there is no response from the heart.  No P-waves, no QRS complexes, just lone pacer spikes hanging out.  This is classic failure to capture.  Possible causes of this can be a fractured or dislodged lead, battery failure or electrolyte abnormalities among others.  Luckily in this case the patient has an intrinsic rhythm that is probably perfusing them.

The second item shown is failure to sense.  Notable for this is the pacer spikes in the ST-segments.  Failure to sense is exactly what is says, the pacer is failing to sense the cardiac cycle and inappropriately pacing.  Again, luckily in this case the pacer is not capturing so the inappropriate pacing is not causing issues.  The biggest problem with this failure is inappropriate firing when the heart is not quite yet refractory possibly initiating ventricular arrhythmias.  Causes of failure to sense include lead issues (dislodgement, fracture or poor positioning) or sensitivity issues requires a change to sensitivity.

In this particular case, it appears the patient is in atrial fibrillation, which may be causing issues with both capture and sensitivity.  The erratic electrical signals emanating from the atria may be throwing off the pacer, but many times they are programmed with this in mind.  For nurses the important things to remember is to check on the patient when the pacer is acting up and ensure they are stable.  Past that, with permanent pacemakers, we need to get the cardiolosit involved.  If it the nurse who is running a temporary pacer at the bedside, adjustments to both output and sensitivity may be required to ensure adequate sensitivity and capture (but that’s a whole other ball-game!).

Here’s what a pacer strip should look like:

Each spike has a corresponding activity, just like it should.

Skynet Anyone?

French fighter planes grounded by computer virus – Telegraph

No thanks in part to Microsoft, but this reeks of so much of recent sci-fi writing almost feels like it was either planned or just a freaky conicidence.  Even Skynet started somewhere….

Yes, I’m a sci-fi geek.

Freaky Weird EKG

Check it out…

Is it flutter, is it fib, what the heck is it?  Anyone want to play?

Angiography: Live and In-Person

BBC NEWS | Health | Watch an emergency heart procedure

This is far too cool.  Patient is a 36 year old male, with a blockage of his RCA (according to the cardiologist). Risk factors?  Smoking. I lived in England for 3 months and am sure that smoking was not the only risk factor…but.

I wish they had displayed a copy of the EKG, but I would venture to guess there was some ST-segment elevation for them to rush him back to the cath lab so quickly.  They show a fluoro shot of the dye being injected then stopping, which gives a great visual representation of what is going on.  You can see how it is pretty much totally blocked.  Then they also show a fluoro shot prior to stenting where you can see the narrowed lumen of the artery. Unfortunately, these shots are pretty much fleeting in nature so to get the best view you would have to pause the video, which I highly recommend.

It’s fun, especially when the patient has a bit of a reperfusion arrhythmia!

via Dr. Wes

Junkfood Science: National Patient Registry

Junkfood Science: National Patient Registry

The article explores the various legal and ethical pitfalls associated with EMRs…and it’s incredibly fascinating.  And it is a little scary, to realize that the creation of a national database would have far reaching effects onto the delivery of care and the provisions of privacy (or lack thereof).  One thing that struck me was the discussion of HIPPA and privacy, citing Supreme Court dialogs about the privacy of a persons’ medical record.

Being involved in an EMR transition project it brought up things I didn’t really consider and it is great food for thought.  It’s heavy reading but well worth it.