Wednesday, November 16, 2011

A New Small Cardiac Assist Device

Devices - The Future of Medicine



Cardiac Assist Device

Let’s consider some other devices that can be helpful for patients with heart problems, in particular, patients with heart failure. I will illustrate with the story of Ron Caspian, a fifty-nine-year-old analyst with one of the think tanks that surround Washington, DC. In the fall of 2002, he developed some chest discomfort one Saturday morning. His wife and daughter were out shopping, so he drove himself to the nearby emergency room where it was quickly confirmed that he was having a heart attack.

Indeed, his heart rapidly began to fail, and he was rushed to the cardiac catheterization laboratory where an angioplasty was performed. This opened up the major blocked artery, but his heart muscle was dangerously weak. His cardiologist telephoned a cardiac surgeon at the hospital where I worked and asked if he could transfer the patient while adding, “But I’m not sure you’ll be willing to accept him.”

The surgeon, never one to give up easily, asked, “Why not?” “Well, because despite the angioplasty, his pulse is very rapid, his blood pressure is zip, his kidneys are not making much urine, and his blood flow is so limited he is semi-comatose.” “Send him quick,” said the surgeon, who geared up to insert a cardiac assist device. The idea is to let the heart rest while a mechanical device does much of the pumping for the heart. It is hoped that after a few days the heart may regain some of its function and be able to carry on its role once again.

So Mr. Caspian was transferred, and the cardiac assist device was installed. It is about the size of your fist and fits around a portion of the heart and through a pneumatic system helps the heart pump blood to the body. The large pneumatic driver that powers the assist device is housed in a small suitcase-like affair that the patient must keep next to him all the time.

I saw this gentleman when I came to work on Monday morning, and he certainly did not look well-although the surgeon was quite pleased. By Wednesday, Mr. Caspian was sitting up and really looking pretty good. This was remarkable because there is no question he would have died on Saturday afternoon if not for the quick work of the cardiologist in doing an emergency angioplasty and the cardiac surgeon in implanting the cardiac assist device.

After a few more days, however, it became evident that Mr. Caspian’s heart was just not going to recoup and that he would need a heart transplant to survive. But a heart for transplantation becomes available only every so often, and in fact, most patients die before a heart is ever available.

What to do? The cardiac surgeon decided-with the advice and consent of both the patient and his wife-to try a new device. It is about the size of a D battery, like the one you use in your flashlight, with a little electric turbine inside; yet it can move blood, not quite in the amounts that a normal heart can pump, but still enough to keep the body functioning at a fair level of activity.

The surgeons tell me it is quite easy-for a skilled surgeon-to insert, but the description I am about to give you may not sound all that simple. First, the chest is opened, and then the tip end (apex) of the heart is opened, and this battery-sized device is inserted and sewn into place. Coming out from the heart is a tube about an inch in diameter, which goes to the aorta, that large artery that sends blood to the rest of the body. Also a wire from the little turbine comes out through the chest and hooks onto a battery about the size of a cell phone that can be hooked to your belt. The chest is sewn up. Using electricity from the battery, the turbine moves the blood from the heart out through the tube up to the aorta and into the body.

This device is much smaller than the larger assist device that Mr. Caspian first had installed; it can be left in place for quite some time, and it runs on batteries. Indeed, some even think that this may prove to be a long-term alternative to a heart transplant, a “destination” device if you will. This was placed into Mr. Caspian’s chest, and he did great. He was shortly up and about and after a time went home.

Then about three months later, a heart became available and he had a cardiac transplant. I saw him one day in the hospital coffee shop, and he said that he was going to retire. “I’ve been eligible for three years now and frequently thought about it, but after 9-11 there was so much work to be done at our organization that I just couldn’t leave. But now I know I need to avoid the stress and take care of myself. I have a new lease on life, and I want to make good use of it.”

That all sounded pretty logical to me, but when I saw him again six months later he said, “Well, I just started back to work. They made me an offer I couldn’t refuse. I really need to get out of the house and do some constructive things. But I will be careful. I feel really good, but I do know I need to not get overstressed.”


- Posted from my iPad2

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