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 16th, 2011 by Dinah Miller, M.D. in Health Policy, Opinion
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Electroconvulsive therapy (ECT) is considered to be a highly effective treatment for depression. The story goes that roughly 90 percent of patients respond. The downside is that it requires general anesthesia with all its attendant risks, and patients may suffer from headaches and memory loss. The memory loss is often mild, but there are cases where it is profound and very troubling.
As with any psychiatric treatment — or so it seems — there are those who say it saved them and those who say it destroyed them. Because the risks aren’t minor, the procedure is expensive and often done on an inpatient unit, and people generally don’t like the idea of having an IV line placed, being put under, then shocked through their brain until they seize, only to wake up groggy and perhaps disoriented with an aching head, it’s often considered to be the treatment of last resort, when all else has failed. This makes the 90 percent response rate even more powerful.
I’m no expert on ECT. I haven’t administered it since I was a resident and I don’t work with inpatients where I see people before and after. I’ve rarely recommended it, and then I’ve been met with a resounding, “NO.” My memory of it was that it worked, and that most people didn’t complain of problems. One woman read a novel during her inpatient stay. I asked if she had trouble following the plot (ECT in the morning, novel reading in the afternoon), and she said no.
The Food and Drug Administration (FDA) has been looking at the safety and efficacy of the machines used to perform ECT. It’s a fairly complex story where the FDA advisory panel was considering whether to keep ECT machines categorized as “Class III” machines, which would now require machine manufacturers to prove their efficacy and safety. A reclassification as Class II (and therefore lower risk) would not require this stringent proof. Read more »
*This blog post was originally published at Shrink Rap*
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*
January 28th, 2011 by Elaine Schattner, M.D. in News, Opinion
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The FDA [has] issued an alert about a possible link between breast implants — saline or silicone — and a rare form of lymphoma called anaplastic large cell lymphoma (ALCL). These lymphoma cases are exceedingly rare, but the association appears to be significant.
The FDA identified a total of approximately 60 ALCL cases in association with implants, worldwide. Of these, 34 were identified by review of published medical literature from 1997 to May, 2010; the others were reported by implant manufacturers and other sources. The agency estimates the number of women worldwide with breast implants is between five and 10 million. These numbers translate to between six and 12 ALCL cases in the breast, per million women with breast implants, assessed over 13 years or so.
In women who don’t have implants, ALCL is an infrequent tumor, affecting approximately one in 500,000 women is the U.S. per year. This form of lymphoma — a malignancy of lymphocytes, a kind of white blood cell — can arise almost anywhere in the body. But ALCL cases arising in the breast are unusual. The FDA reports that roughly three in 100,000,000 women are diagnosed with ALCL in the breast per year in the U.S.
These are very small numbers. Still, the finding of ALCL tumors by the implant capsules is highly suggestive. Almost all of the implant-associated ALCL cases were T-cell type, whereas most breast lymphomas are of B-cell type. The lymphomas arose in women with both silicone and saline-type implants, and in women with implants placed for purposes or augmentation and for reconstruction after mastectomy. Read more »
*This blog post was originally published at Medical Lessons*
January 27th, 2011 by AnnMacDonald in Better Health Network, Health Tips
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This picture shows the view from my office window in Boston: Dull, dreary, and depressing — at least on overcast days like today. Lack of light is one of the reasons that people feel mentally foggy.
One of the bloggers I follow, Rachel Zimmerman of WBUR’s CommonHealth blog, recently wrote that she’s been drinking three times as much coffee as usual. In addition to imbibing more caffeine, I’ve been trying to boost my spirits and alertness with mid-day runs to the snack machine (not the best strategy, in case you’re wondering).
At this time of year, many people aren’t just foggy and sad — they’ve got SAD, or seasonal affective disorder. About half a million Americans — women more often than men — are diagnosed with seasonal affective disorder each year. Many others experience at least some of the symptoms, which include loss of pleasure and energy, inability to concentrate, feelings of worthlessness, and an uncontrollable urge to eat sugar and high-carbohydrate foods (in my case, chocolate chip cookies).
Bright white light therapy remains a mainstay of treatment for seasonal affective disorder. That’s because the light acts on cells in the retina, the tissue located at the back of the eye that sends visual information to the brain. The hypothalamus, which helps control the sleep-wake cycle, is one part of the brain that receives this information. During the winter months, when people tend to stay indoors more, days are shorter, and the weather becomes overcast, our exposure to natural light diminishes. That disrupts the sleep-wake cycle, as well as other circadian rhythms. The result can be symptoms of seasonal affective disorder. Read more »
*This blog post was originally published at Harvard Health Blog*
