A stroke does not equal death. A stroke is either a blockage of asupplying artery to the brain (ischaemic stroke) or a rupture of –most often– an aneurysm of one of the intracranial arteries (haemorrhagic stroke). If left untreated, part of the brain dies off, but that is entirely survivable. Old people can have multiple holes in their brains from minor strokes and still walk around. If a large area is affected the patient may become hemiplegic and will need help with many daily tasks and activities, but a stroke generally doesn’t cause death. There are a few exceptions though (see 2.).
A person generally doesn’t just stop breathing with a functioning heart and brain. A rare cause could be a basilar artery occlusion or haemorrhagic stroke affecting the midbrain’s respiratory centre.
We don’t really have a lot of experience with artificial hearts that provide pulsatile flow through pneumatic pumps, the few that have been implanted were mainly for research purposes. What we do have experience with is LVADs, or left ventricular assist devices. These are rotating centrifugal pumps that are implanted inside the heart and aorta and provide laminar, continuous flow. These pumps are so strong they can keep the brain oxygenated even if the heart itself stops pumping (e.g during ventricular fibrillation).
As for your question: death would be brain death or multi-organ failure. The blood would still flow and provide oxygen, but the end organs (including the brain) would not have enough functioning tissue to sustain life. The LVAD would keep pumping until it runs out of battery or is shut off.
The absence of flow is what causes blood to clot.
On top of that, people with an LVAD are continuously on strong anticoagulants (vitamin K antagonists) or heparin.
That being said, it is difficult to tell for sure and clotting would definitely occur in multiple places throughout the body as tissues and organs start to become necrotic, as would haemorrhage due to damaged blood vessels.
But whether the actual pump itself would get blocked before the battery runs out, I don’t think so, since that is where the flow is highest still and the battery pack only lasts a couple of hours before it needs to be replaced.
Yup, there is a cable running through their skin connected to battery packs outside of the body that need to be changed regularly, so patients are always walking around with a bag containing the battery packs wherever they go.
A few things:
Wouldn’t the blood get thick and stop the flow before the battery died?
The absence of flow is what causes blood to clot. On top of that, people with an LVAD are continuously on strong anticoagulants (vitamin K antagonists) or heparin.
That being said, it is difficult to tell for sure and clotting would definitely occur in multiple places throughout the body as tissues and organs start to become necrotic, as would haemorrhage due to damaged blood vessels.
But whether the actual pump itself would get blocked before the battery runs out, I don’t think so, since that is where the flow is highest still and the battery pack only lasts a couple of hours before it needs to be replaced.
Hours?!?
Yup, there is a cable running through their skin connected to battery packs outside of the body that need to be changed regularly, so patients are always walking around with a bag containing the battery packs wherever they go.
If it only lasts a couple hours, how do they sleep for more than 3 hours?
A couple is maybe a bit of an understatement. It’s likely about 8-10 hours