HeartMate II: the pulse-free artificial heart

Since the FDA gave the big thumbs up to a fully implantable artificial heart earlier this month, cardiac surgeon "Bud" Frazier and his team at the Texas Heart Institute aren't wasting any time in developing what they hope will be a fully-functioning, pulse-free artificial heart. The "continuous flow pump" channels deoxygenated blood through the entire body on a non-stop basis, and over two years of testing in cattle, has resulted in lengthening the lives of the previously terminal cud chewers. Replacement hearts that are currently available are too large to fit into folks without "large chest cavities" (including most women), and due to the vast quantity of moving parts, aren't guaranteed to function for an extended period of time. Frazier's alternative, however, is about the size of "an adult thumb," consists of a single moving part (the rotor), and has been designed to keep the blood moving for ten or more years. The HeartMate II can even respond dynamically to the needs of the body, so more blood is circulated when busting a move, and less is pumped when kicking back for a soothing game of competitive relaxation. While the long-term consequences of living a pulseless life are still under debate, Frazier's group is hoping to move forward with development -- and apparently challenge medical personnel everywhere to find a new way to monitor those vital signs.

[Brian @ Sep 22nd 2006 7:14AM]

You know you're in Texas when your cardiac surgeon is named "Bud"

[David @ Sep 22nd 2006 7:16AM]

...channels deoxygenated blood through the entire body...

So who didn't go to their biology class?

[DarkFader @ Sep 22nd 2006 7:25AM]

Perhaps the one with oxygen is simply bypassed? At least the one which is lacking of oxygen can be measured properly.

[David @ Sep 22nd 2006 12:36PM]

Can someone edit this already? It's oxygenated blood that the body needs - you need deoxygenated blood being pumped into your system circulation like you need a pitchfork in your head.

[Michael @ Sep 22nd 2006 7:33AM]

I'd hate to be wearing one of those and have some good meaning rescuer find me with no pulse while I was sleeping. Waking up to a defibrillator is not a happy prospect.

[Tim @ Sep 22nd 2006 11:50AM]

Yeah, this is totally going to screw with CPR training as we now know it...

"OK, so if there's no pulse, it *could* mean that they're dead. Or not. But don't do chest compressions, 'cause you might bend his rotor. But don't NOT to chest compressions, 'cause he might be dying. Essentially, do nothing."

[David @ Sep 22nd 2006 10:09AM]

I'm sure evolution/nature developed pulse for a reason.

[aeo @ Sep 22nd 2006 10:58AM]

Um yeah.. because meat can't act like a rotor. It can only contract/relax and thus the squeeze bulb type of pulmonary system. In short, nature has developed a pulse because its all she had to work with.

[RickDom @ Sep 22nd 2006 10:47AM]

Well...it's not so much that there is a reason for a pulse, it's more to do with your body being built around having one.

I, for one, welcome our new pulseless cyborg cow overlords.

[rj @ Sep 22nd 2006 10:59AM]

The "reason" is that it's about the simplest way to make a strong pump out of meat.

[Alex @ Sep 22nd 2006 11:04AM]

I wonder if they could eventually pulse the turbine to simulate a beat...

[64bprophet @ Sep 22nd 2006 11:07AM]

How strange would that be to NOT have a pulse? I think effectively you would have no way of knowing if the person's heart was actually working or not. It's crazy strange to think about the full ramifications of not having a pulse.

~B.

[Chad @ Sep 22nd 2006 11:51AM]

IMO, this is one of those "DUH" moments where you wonder why artificial hearts didn't start out this way. Why go to all the complexity of trying to replicate the pumping of a heart, when a continuous flow pump is 100x simplier?

[Erik @ Sep 22nd 2006 12:22PM]

lol, it's funny reading comments from people who have no clue what they're talking about...I love engadget!

[tekdemon @ Sep 26th 2006 12:37PM]

Umm...well for one thing our blood vessels evolved to work with a beating heart...and without a constant beat who knows what'll happen.

Just for example, the constant stretching and tightening of the vessels might help keep them flexible. Since you no longer have a pulse, your blood vessels might start to get less and less flexible just from the lack of having to stretch. This is just a theoretical example that I'm thinking of, but it's still something that has to be addressed.

Plus, the extra pressure might actually help to get certain things in your blood past membranes, etc. Who knows?

Of course it could also turn out that not having a pulse is a good thing, maybe it puts less stress on your vessels and actually is good for you.

I guess we'll find out though =)

Wait...is this the beginning of...borg? I mean if we found out a pulseless heart was actually superior (ha crazy fast beating heart definitely doesn't feel very good in your chest cavity since it's hitting everything nearby, and you could probably build a constant pumping heart that pumps quite a bit more volume since there's no pause) wouldn't people be tempted to upgrade even if their own hearts work pretty well?

Haha, I can't wait to spec myself out with some new organs ;)

[Aeon @ Sep 22nd 2006 11:54AM]

what needs to be done as far as notifying paramedics and other medical professiopnals of the fact that a patient is equipped with a pulseless heart is a braclet, just like we already use to notify medical professionals of an alergy to certain medicines or of preexisting medical conditions.

On that note, a wireless link to a bracelet or diagnostic device could inform paramedics of the status of the heart, replacing the diagnostic information previously provided by the pulse.

Aeon

[Dario @ Sep 22nd 2006 12:16PM]

do you guys think its a sin to remove ur heart and replace it with a artificial heart??... im not religious, just something i thought of askin.

[Matthew Palmer @ Sep 25th 2006 10:16PM]

I think its a sin and a bad ethic or moral to assume its a sin to receive the gift of extended life through science.. I think its a sin to even ask that question as it demands a religeous response by zealous and religeous fanatics on incorrect malice grounds.. It is worth responding to because it attepts to right an ignorence.. No offense its a bad moral that has the potential to become a bad ethic or other peoples moral imposed on someone else.. lllBewiselll

[Adam @ Sep 22nd 2006 12:45PM]

this is just a LVAD (left ventricular assist device) it aids the half of your heart that circulates blood to your body, it does not replace or augment the right ventricle that supplies blood to your lungs. Devices like this have been in use for decades as a bridge to transplant.

[brian @ Sep 22nd 2006 12:53PM]

when u dont have a pulse and your still walking around doesn't that mean your a zombie? brains

[Nick @ Sep 22nd 2006 1:22PM]

If you guys would just read the short 2 page article, it would clear a lot of thing up. The main one being:

- yes these things have been around a LONG time, but as assist devices. The article is taking about a full-fledged implantable heart based on one of these devices.

My own thoughts:

- The circulatory system is based on having pulsatile flow. For example the Aorta provides immediate damping to the pulse wave leaving the heart due to its distensible nature. The pressure driving the blood flow is pulsile all the way into the capillaries. I for one am not convinced the body will react favorable to a steady flow, especially in the long run. Maybe having a steady flow could encourage platelet aggregation in major arteries. No one knows just yet.

[Allan @ Sep 22nd 2006 1:39PM]

How difficult would it be to have some sort electronic device that would simulate a pulse to compliment the pump? Like say maybe an ipod nano stuck on repeat playing a pulse mp3(legally downloaded from itunes of course). Just my .02

[PosiCat @ Sep 22nd 2006 2:48PM]

Cool, get rid of this pesky heart, and there's almost room enough to put in an embeded computer along side the heart. I want a blood-cooled-quad-core Opteron in my chest!

[T-Will @ Sep 22nd 2006 5:18PM]

Wow strong heart.

[Joel @ Sep 22nd 2006 7:40PM]

But you've got to have a pulse... THATS WHAT SEPERATES US FROM THE ANIMALS!!

[Fat's @ Dec 30th 2008 3:29PM]

Dude COME ON!! animals have a pulse too!! OH GOSH!! what the F!!

[PumpGeek @ Mar 31st 2007 10:29PM]

I studied hydraulic pumps in college(specifically relating to oil/water) and I find this challenge for new system of vital signs for these new "pulseless wonders" fascinating.

A new system would have to be created to verify not pulse, but circulation instead.

Human hearts typically circulate anywhere from 5 liters of blood per minute at resting to up to 40 liters per minute during EXTREMELY strenuous activity in athletes.

That means the circulation capacity requirements of the variable speed pump is no greater than 11 US gallons per minute at full throttle.
(The only question is, what kind of battery, and how long can it last before recharging?)

[Kay @ Aug 22nd 2007 9:32PM]

What about the simple FACT that the cardiac cells have their own intrinsic pulse.....??? Would you NOT be able to detect that??? An ECG would, for sure...........

[ledesmakrew @ May 20th 2008 7:49PM]

I HAVE BEEN IMPLANTED WITH THE HEARTMATE 1 LVAD.
AND SOME OF YOU PEOPLES SOUND LIKE IT IS A GREAT BIG JOKE!
IF I WAS NOT IMPLANTED WITH THIS DEVICE UNTIL AN ORGAN DONOR IS FOUND I WOULD HAVE DIED.

[Kendra @ Jun 19th 2008 12:44PM]

For vitals, try a BP cuff and doppler

[JR @ Oct 24th 2008 5:29PM]

Anybody know where I can get more information on the fact that LVAD patients are prohibited from driving a car. The WIsconsin DMV has been less than helpful...

Thanks

[Darcia Pratt-Eriksson @ Mar 27th 2009 9:13AM]

Heartmate 2 is a good device. I am a living proof. I am Sweden and scandinavia first patient to have "bridge to recovery ". Meaning the pump was explanted in December 11th 2008 at Karolinska Hospital successfuly without needing a heart transplant. This device saves lifes. Today am doing fine and i dont feel like a heart patient

I am indeed greatful to Thoratec and Karolinska Hospital. If you want to know how this works ask me.