CHANGE THE PROTOCOLS. THE LACK OF A PULSE doesn’t always call for CPR or de-fib anymore. Not now that people are walking around with a new-design artificial heart that pumps continuously, i.e. no pulsing.
Our friend Sabotank sent along THIS ARTICLE from the Singapore Straits Times that says in part:
MADAM Salina Mohamed So’ot has no pulse. But she is very much alive.
The 30-year-old administrative assistant is the first recipient here to get a new artificial heart that pumps blood continuously, the reason why there are no beats on her wrist. Older artificial hearts usually mimic the heart’s pulsations.
And the petite Madam Salina, who suffers from end-stage heart failure, would not have been able to use the older and bulkier models because they can only be implanted in patients 1.7m or taller.
These are becoming so commonplace now that four of them have been implanted in the past four months in Singapore. The device was developed in the U. S. by O.H. “Bud” Frazier, a prominent heart surgeon and pioneer in the development of cardiac devices at the Texas Heart Institute in Houston. He introduced the device called the HeartMate2 three years ago and it has now reached approval for use.
As the Straits Times article mentions, the standard artificial heart is too large for small-statured people, but this new continuous-pump heart is only the size of an adult’s thumb.
An article in the MIT Technology Review from September, 2006, explains how the device works:
“Continuous flow pumps are like little turbo machines,” says Tim Baldwin, program director of the advanced technologies and surgery branch of the National Heart, Lung and Blood Institute in Bethesda MD. “They are more durable and allow you to make smaller devices.”
With Frazier’s continuous flow design for an entirely artificial heart, a severely damaged heart is removed and replaced with two rotor-based pumps that continually cycle blood through the body, completely taking over the function of the heart.
The biggest advantage to the rotor-style or axial pumps is that they are small and relatively simple. The AbioCor heart, for example, is so large that it can only be implanted in people with large chest cavities, making it inappropriate for most women. “Axial pumps are about the size of an adult thumb and can pump more blood than a normal heart,” says Frazier.
Continuous flow pumps are also more durable, due to the simplicity of their design–the only moving part is the rotor. “Other pumps work well, but there are lots of moving parts so they are subject to mechanical wear,” says Cohn. The longest the AbioCor heart functioned in clinical trials was 18 months, while continuous flow devices are being designed to operate for 10 or more years.
Another advantage of the continuous flow pump is its ability to increase flow on demand, much like a real heart. If the patient gets up and starts walking, for example, the device senses the call for more flow and speeds up accordingly.
You can read the full article from the MIT Technology Review HERE.
Have any Firegeezer readers come across any patients without a pulse yet? Tell us your experience.
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