25-year-old lived for more than a year without a heart | Hacker News Reader

25-year-old lived for more than a year without a heart

sciencealert.com

293 pointsrocketpastsix85 comments

Admittedly I didn't read the whole story, the click-bait title got me.

I had a girlfriend with a similar device attached to her (an LVAD). At first it was a little unnerving seeing her unplug the batteries that were keeping her alive and charge them every night. It quickly became normal for me. Life with it seemed relatively normal except she had to have a purse with her at all times (it carried the batteries).

The interesting part was when she received a transplant and went cordless. After being attached to it for two years and not having a heartbeat the sound of her heat beating kept her up at night for a couple of weeks. I hadn't even considered the beating of a heart to be relevant to our daily lives until she had mentioned it once she heard hers beating again (an LVAD is just a constant velocity pump. The blood is always flowing).

Not sure how much it really adds to the conversation other than an interesting anecdote.

Wow, I had no idea you have no pulse when you have an LVAD. That's really neat.

Do you have any idea if there have ever been studies on the effect of constant flow vs peristaltic flow on the circulatory system? I wonder if the constant flow creates or solves any issues.

That continuous flow is new(-ish). My father had an LVAD in 2002, and it was the older type that actually pumps rhythmically, so that was his pulse. At the time continuous-flow models were in research, and I do remember there were concerns with thrombosis (basically, the shifting force of the pulse helps break up clots).

I don't know the current state of the art, but there are definitely studies (the keyword is "pulsatile"). For example:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4250555/

For comparison, here's a picture of some LVADs. The one I've seen in person (after it had been taken back out!) is the one on the far left. Flow issues aside, I can imagine the smaller ones are easier on the patient in general, just from the perspective of surgery trauma.

http://reliantheart.com/wp-content/uploads/2013/04/VAD_Size_...

To elaborate a little bit more: the first generation of LVADs were had large mechanical pumps and were huge -- they could only be implanted in people with a large chest cavity, excluding a large number of patients (especially women) from eligibility for their device.

Current popular models are continuous flow rotors that are much smaller (enabling their use in almost anyone) and are non-pulsatile.

However, there's been a big push to move towards pulsatile devices. This is mostly driven by mechanobiolgy studies that show that there is a difference in the cellular programs of cells that are exposed to a continuous shear force versus a pulsatile shear force. Accordingly, to more closely replicate the natural physiology of the heart, there has been a big push towards using pulsatile devices.

How do you perform CPR on a person with an LVAD? Plug the device in.

I'm not being snarky. I saw several patients with LVADs on my cardiology rotation in medical school. As far as I know they are the only patients exempt from CPR if they have a cardiac arrest, although device failure should be the only reason for this.

There is a difference between pulse and heartbeat, the pulse is from the veins and you can feel it even with an LVAD.

The audible heartbeat is from the heart sliding in the pericardium sac when it beats, many people lose the audible heartbeat after having heart surgery when the pericardium sac has to be cut or removed completely e.g. if someone is having a bypass surgery.

Peripheral Veins are not pulsatile (near the heart, they have a complicated waveform). Peripheral pulse is arterial.

The audible heartbeat is from the valves closing.

Yeah! Maybe the OP has the heart sounds confused with a pericardial friction rub, which can happen in pathological states and is due to the heart sliding against the pericardium.

I didn't know there was a difference in terminology when I asked. This was a worthwhile question - I learned a lot.

Thanks for the great explanations!

I knew about the continuous flow, but hadn't considered that you wouldn't hear your own pulse as a result. My father in law has an LVAD, which has given him back a lot of freedom following a severe heart infection early last year which damaged his natural heart badly. He's now on the transplant list, so I'll point it out to him as a "hey, this could be weird" thing.

Do they mean that blood pressure is stable too, since you presumably wouldn't have a diastolic reading - no pressure reduction between beats, since there are no beats?

The diastolic reading isn't about pressure reduction in-between heartbeats but about the pressure created by the vascular walls.

When you usually measure blood pressure you increase the pressure to a value that's likely above the systolic value of the patient (say 180). Then you gradually release pressure. Once you hear a heartbeat that's the systolic value. Once you stop hearing the heartbeat that's the diastolic value, which is the vascular walls resisting the heartbeat

In this particular case instead of the usual heartbeat you'd likely hear something more like a constant flow but you'd still have systolic and diastolic values.

"Clearest explanation" award for that second paragraph.

So that's how doctors do it with a manual pump and stethoscope. Never thought of asking one ...

Just to expand:

With a blood pressure cuff, what you are doing is collapsing the arterial wall with outside pressure. You increase the pressure above systolic blood pressure and then gradually reduce it until you hear a sound. This sound isn't the heartbeat, but is instead the result of turbulent flow in the blood vessel. While you are between systolic and diastolic pressure, only spurts of blood can flow through the vessel creating noise. Eventually, you reduce the pressure enough and blood even during diastole (which is lower pressure) can expand the walls of the artery against the blood pressure cuff.

So, in both cases what you are hearing is due to blood pushing open the vascular walls.

There are two types of LVAD's- continuos flow and pulsed. LVAD's "piggyback" onto the existing heart and provide additional force to the left ventricle (which pumps blood to the body). The biggest issue with LVAD's is immune rejection and plaque buildup. As the body responds to a foreign object it will frequently form plaques on the LVAD's internal valves. It's very challenging to determine if this plaque buildup is occurring without literally opening up the patient's chest via surgery. If the plaque breaks loose, they frequently cause stroke or pulmonary embolisms.

Not an expert, but from reading what an LVAD is and reading the article, these are two very different things. He had a full heart replacement device strapped to his back. As in, the blood ran out one tube, into the pack, then back into his body. An LVAD is an internal pump for the left side of the heart and you just provide it power externally. Not to discount your girlfriends experience at all, but that seem quite different.

EDIT: Actually, watching a video, it looks like the tubes are for air maybe? Weird device in any case.

Click-baiting titles on sites these days are probably driving people to the comments section first rather than RTFA. Crowd-sourcing and displaying in-place article titles on sites would make for a great browser extension. Might be as bad for site owners' short-term business goals as ad-blockers are.

Artificial heart designers may thus consider doing something to simulate the noise and vibration of a heart beat, to prevent any awkwardness after the transplant.

I gotta say, this is a rare case where the link-bait title wasn't so much link-bait as a succinct description of what was in the article.

That's amazing. It's both awe-inspiring and unnervingly depressing to be reminded that we are ultimately just biological machines.

Reminds me of that procedure where a surgeon can freeze you, drain your blood, take out all your organs and then put them back in, stitch you up, pump blood back in and then warm you up and awaken you. It was like unplugging your PC, taking it apart and then putting it together and turning it back on.

Please think about becoming an organ donor. It is completely ok to decide against it. At least you have contemplated the idea.

http://www.organdonor.gov/

Where I live it is opt out, not opt in.

Same here.

same. people that opt-out have 'non-donor' on their ids (my father is not a donor -- not sure why tbf)

No need in my country, it is opt-out instead of opt-in :)

Should be in the UK as well, it's been floated a few times as an idea.

As of December 2015, it is opt-out in Wales.

I registered as a donor in the UK. I received a leaflet saying that I should discuss this with my relatives because apparently those people have the power to kill the person needing my organs [1]. Fuck that.

[1] https://www.organdonation.nhs.uk/news-and-campaigns/news/fam...

Fun fact: The book Infinite Jest includes a character who keeps their artificial heart in their handbag. In one scene, the handbag is snatched by a passing thief which leads to the character shouting "She stole my heart, stop her!". As expected, this is tragically misconstrued by passersby who believe that the woman was in the middle of a sad yet not unexpected lovers quarrel, whereas in actual fact her heart had been stolen. Tragicomedy in the same scene.

Separate thought, if you were to replace your lungs with a machine that oxygenated your blood, could you calmly sit without breathing? Is the anxiety/impulse to breathe do to a lack of oxygen?

It's from buildup of co2. You would need to scrub that.

In particular, in an environment that has insufficient oxygen in the air but that doesn't have carbon dioxide, you don't feel a desperate need to breathe; you just pass out and die.

This can and does kill people, in a variety of low oxygen situations. E.g. labs with liquid nitrogen freezers are mostly now fitted with O2 alarms to warn occupants about a dangerous and undetectable low O2 situation. Since you're still able to expel CO2, you literally won't feel anything wrong until you just collapse and quietly asphyxiate. Movies get this wrong all the time, and it bugs the heck out of my biotech friends with safety training with aforementioned labs.

But at least it's a totally painless and stress free way to die.

Your body will prompt you to breath when either CO2 levels are too high or O2 levels are too low. In your example the subject is still breathing even if he isn't getting O2.

One problem ER docs see periodically is the CO2 "sensor" can become broken in patients with chronically high blood CO2 levels, i.e. people with certain types of COPD. They only breath when their blood O2 levels are low, and if you give them oxygen they just stop breathing.

This is not true; just about any relatively non-toxic inert gas other than CO2 can take the place of oxygen without any significant response.

We do have a hypoxic respiratory drive, but it is exceptionally weak, and unconsciousness will occur before any noticable distress is noted.

The hypercapnia alarm response we're all familiar with is tied to carbon dioxide levels, not oxygen.

What's not true? That he's not breathing?

Hence the recommended method of life exit for people with terminal illness is to use a hood connected to Helium. Of course you need some "assistants" to remove the evidence since most places assisted suicide is illegal.

I guess one thing to look out for is the smell of rotten eggs in a server room. From what i understand that is a sign that the UPS batteries are venting hydrogen sulfide.

That or sulfur dioxide, yeah. I've smelled the latter in an office that doubled as a data center, when one of the UPSs' charge regulation circuit went wonky and overdrove its batteries.

That's probably not a major asphyxiation risk unless you're trapped in a room with it, though, because, unlike inert gases like helium or nitrogen, sulfur compounds are irritating as hell - a UPS boiling its batteries will send you fleeing for the nearest source of fresh air, with eyes and nose streaming, before it'll suffocate you.

Excuse the morbidity, but if this type of asphyxiation is essentially pain and stress free, would it not be a humane method for euthanasia or even for capital punishment?

Yes it would.

Yes. It's been approved for capital punishment in the US state of Oklahoma:

http://www.newyorker.com/news/news-desk/how-oklahoma-came-to...

Also search for “exit bag”. You’ll find instructional images, as well as an instructional video made for the sick and elderly, about using this technique to commit suicide.

It sure would. If I had to be executed and could choose my method, I would choose this.

I don't know why it's not universally used. I suppose it's some combination of tradition and a belief that executed criminals should suffer.

This is inert gas asphyxiation [1].

CO2 buildup is what drives the panicked "I can't breathe" response. If there's no CO2 buildup and no oxygen, it's a rapid and apparently peaceful lights out.

[1] https://en.wikipedia.org/wiki/Inert_gas_asphyxiation

It's due to the buildup of carbon dioxide.

https://en.wikipedia.org/wiki/Respiratory_center

How many organs can you do this for? Heart, lungs, kidneys at least. 'Brain-in-a-jar' seems like the most achievable form of immortality at the moment.

Our bodies are more complex than we can design for yet. Most organ replicating machines will start to fail after a couple of hours due to complications like clots. The heart is probably the simplest due to it's very simple function. We also have kidneys mostly working. But everything else is still problematic.

Yes, you could sit without breathing. They do this in surgery all the time (heart/lung machine).

I suspect they want to minimize the blood's contact with anything because blood likes to clot, so doing it longterm without blood thinners might not work so well.

That's what is so amazing about this device: All other devices before it threw off so many clots they killed the patient rapidly.

Lookup "Jarvik" for some of the history.

This oxygenator[1] along with a load of other kit and gas supplies replaces your lung function during a heart bypass. It swaps O2 and CO2. But it only works for hours before clots start to become a problem. The fibres in the oxygenator are coated with heparin to delay the complications.

[1] http://www.medtronic.com/affinity/

edit: forgot the link!

You could fill them with a oxygen providing fluid?

https://en.wikipedia.org/wiki/Liquid_breathing

The pump is shown in this video: https://www.youtube.com/watch?v=i9WUHSJrhm4

It's surprisingly loud

Geez I wonder if it makes that noise the whole time you have it or if it goes through cycles.

That would drive me crazy, but hey you get to live.

There is a great NYT documentary on artificial hearts and the history behind it: https://www.youtube.com/watch?v=0Xn5u-LzsW8

It starts with the Jarvik-7 artifical heart from the 1980s (first seen as a success, then as a failure) and then moves on to today's temporary and permanent artifical hearts.

Really interesting documentary. Thanks for posting this.

-----

Some highlights:

- these new SynCardia artificial hearts are basically the same as old Jarvik-7 hearts (part that goes inside patient's chest), save for different sizes available today

- just the external part is now more modern (thanks to advances in power sources they can be now portable)

- big problem with Jarvik-7 at those earlier times were infections and blood clotting (leading to strokes), but doctors today know better how to manage this (as far as I understood, this is not due to better mechanical design of the heart but due to better medication / monitoring / protocols compared to ~30 years ago)

- these new SynCardia hearts were used for already ~1,600 patients (as "bridge" while waiting for heart transplant)

- FDA approved trial for use of these artificial hearts as permanent solution (no heart transplant needed), the first patient already got implanted this heart for permanent use

See also this reddit AMA (Ask Me Anything) thread from another patient with such device from 2 years ago (2014):

https://www.reddit.com/r/IAmA/comments/24a8ln/hello_reddit_i...

I wonder if it affected his mood at all. I mean is the heart pumping of anxiety or anger a symptom or part of a feedback loop?

Even if it is, I assume everything that comes with knowing you don't have a heart is too much of a factor for this to be measured/evaluated.

What is the feedback loop that regulates the artificial heart's pump rate, assuming it exists at all?

There isn't any. The vagus nerve helps regulate heart rate, but artificial hearts don't change their pump rate to internal factors.

Not true. The Carmat heart increases and decreases pulse rate in response to changed hormone (or some other biomarker) levels

It's the body telling the heart "Pump more, we need extra oxygen".

Not having a heart doesn't change his mood, his mood changes the heartbeat.

That's why there were so surprised he could play sports - without that acceleration he might not have enough bloodflow for his activities.

I wonder if it has a knob to manually adjust the flowrate.

Or maybe since it's mechanical it's fine for it to run at max at all times? That might not be good for the rest of the vascular system though.

If that's bad for the vascular system then an idea would be to measure O2 saturation in the toes, and adjust the flow if it gets low.

I would guess so because beta-blockers are also prescribed for anxiety as well as various heart conditions, and breaking the feedback loop is the intended effect. I'd imagine therefore that you'd be a bit less anxious as a result.

Carmat have a competing device that's been implanted in 5 patients so far. It is much more technically advanced, with Alan Carpentier designing, I think, to prevent blood clots. However, it's. A pump based device Nd the jury is still out on how long pump based devices can last. They expect the xarmat heart to last 5 years.

Carmat gets a lot of bad press when each patient with their pump dies, even though the press does not realise patients would be long dead without them.

I don't know if the press are that important tbh. They have now progressed to clinical trials. If they are successful they will make and sell millions of them. 23andme showed that press isn't that important in medicine - pleasing the FDA is the name of the game.

The Bivacor is another interesting device based on pumpless technology. Good read this http://edition.cnn.com/2013/12/04/health/permanent-artificia...

Artificial KIDNEY will be a boon for human beings

Love seeing these stories about the will to live and fighting through hardship and making the most of every opportunity. These sorts of folks - who just want to be normal - really strike a chord with me. Fascinating specific instance and type of treatment.

I wonder if it is just better to have the artificial heart for the rest of your life? With all the complications with having a heart transplant, it seems like it could be equally dangerous.

Note, I'm a lay person, and have no clue. Just pondering.

Presumably the doctors involved are balancing the various trade offs when they go with the transplant.

Its good to hear people are working on things like these, artificial hearts prolonging life. Gives some perspective and your own problems pale in comparison.

I don't know why for a second I've read that he lived more than a year without internet.

Wow, would hate for one of those supply lines to fail :|

whoa, one step closer to becoming cyborgs.

That surprises me. I thought that we had ample proof that Cheney lacked a heart.

Cute.

We detached this subthread from https://news.ycombinator.com/item?id=11859827 and marked it off-topic.

This is not new or particularly interesting. Dick Cheney had one of these for a long time. I knew someone who had one too. I'm not sure why this is being written about as if it's new.

https://en.wikipedia.org/wiki/Ventricular_assist_device

The above seems to be what Cheney was outfitted with.

The syncardia system mentioned in the article appears to be a full heart replacement unit.

It's somewhat different. Cheney still had his heart inside his body. This device is a total replacement.

http://www.syncardia.com/medical-professionals/tah-for-medic...

This guy also played basketball with this - and also, it is a external machine worn as a backpack! So it is new in big ways.

Cheney had an LVAD, not one of these.

How could you be so heartless! Oh, how could you be so heartless!

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