February 18th, 2011 by Mary Knudson in News, Opinion
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This was the Guest Blog at Scientific American on February 16th, 2011.
New wave of MRI-safe pacemakers set to ship to hospitals
This week Medtronic will begin shipping to hospitals in the United States the first pacemaker approved by the FDA as safe for most MRI scans. For consumers, it is a significant step in what is expected to be a wave of new MRI-compatible implanted cardiac devices.
But this is an example of one technology chasing another and the one being chased, the MRI scanner, is changing and is a step ahead of the new line of pacemakers. The pacemaker approved for U.S. distribution is Medtronic’s first-generation pacemaker with certain limitations, while its second-generation MRI-compatible pacemaker is already in use in Europe where approval for medical devices is not as demanding as it is in the U.S. So let’s check out what this is all about — what it means now for current and future heart patients and where it may be headed.
We are all born with a natural pacemaker that directs our heart to beat 60 to 100 times a minute at rest. The pacemaker is a little mass of muscle fibers the size and shape of an almond known medically as the sinoatrial node located in the right atrium, one of four chambers of the heart. The natural pacemaker can last a lifetime. Or it can become defective. And even if it keeps working normally, some point may not function well along the electrical pathway from the pacemaker to the heart’s ventricles which contract to force blood out to the body.
Millions of people in the world whose hearts beat too fast, too slow, or out of sync because their own pacemaker is not able to do the job right, follow their doctors’ recommendation to get an artificial pacemaker connected to their heart to direct its beating. The battery-run pacemaker in a titanium or titanium alloy case the size of a small cell phone, (why can’t it be the size of an almond?) is implanted in the upper left chest, just under the skin, with one or two insulated wire leads connecting to the heart. It can be programmed to run 24/7 or to only operate when the heart reaches a certain state of irregular beating. Read more »
*This blog post was originally published at HeartSense*
February 2nd, 2011 by Mary Knudson in Health Tips, Opinion
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I confess to loving Campbell’s tomato bisque soup. I mix it with 1 percent-fat milk and it’s hot and delicious and comforting, but one of the worst food choices I could make because one cup contains more sodium than I should have in a day. Knowing this, I have already relegated it to an occasional treat. But by the end of this blog post I will do more.
We are overdosing on sodium and it is killing us. We need to cut the sodium we eat daily by more than half. The guidelines keep coming. The U.S. government has handed out dietary guidelines telling Americans who are over 50, all African Americans, people with high blood pressure, diabetes, or chronic kidney disease to have no more than 1,500 milligrams (mg) — or two thirds of a teaspoon — of sodium daily. That’s the majority of us — 69 percent. Five years ago the government said that this group would benefit from the lower sodium and now it made this its recommendation. The other 31 percent of the country can have up to 2,300 mg a day, say the guidelines from the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services (HHS).
Or should they? The American Heart Association (AHA) recommends that all Americans lower sodium to less than 1,500 mg a day. Excessive sodium, mostly found in salt, is bad for us because it causes high blood pressure which often leads to heart disease, stroke, and kidney disease and can also cause gastric problems. People with heart failure are taught to restrict salt because water follows salt into the blood and causes swelling of the ankles, legs, and abdomen and lung congestion that makes it difficult to breathe.
I saw one recommendation by an individual on the Internet to just drink a lot of water to flush the sodium out of your body rather than worry about eating foods that have less sodium. BAD idea, especially for people with heart problems who need to restrict fluids to help prevent fluid accumulation in their bodies. The salt will draw the water to it.
But cutting our salt consumption by half is quite a tall order for an individual consumer because Americans have been conditioned from childhood to love salt and we on average consume 3,436 mg — nearly one and a half teaspoons — a day. Sodium is pervasive in our food supply. We get most of our sodium from processed foods and restaurant and takeout food, sometime in unexpected places. Read more »
*This blog post was originally published at HeartSense*
