March 5th, 2011 by John Mandrola, M.D. in Opinion, Research
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It’s hard to believe that turbulence could be a good thing for the heart. Consider how the word turbulent is defined: “Characterized by conflict, disorder, or confusion; not controlled or calm.” Those traits don’t sound very heart-healthy. But when it comes to heart rhythm, it turns out that a turbulent response — to a premature beat — is better than a blunted one. The more turbulent the better.
No, you haven’t missed anything, and turbulence isn’t another of my typos. Until [recently], heart rate turbulence was an obscure phenomenon buried in the bowels of heart rhythm journals.
What Is Heart Rate Turbulence (HRT)?
When you listen to the heart of a young physically-fit patient, you are struck not just by the slowness of the heartbeat, but also by the variability of the rhythm. It isn’t perfectly regular, nor is it chaotic like atrial fibrillation (AF). Doctors describe this — in typical medical speak — as regularly irregular: The heart rate increases as the patient inhales and slows as he or she exhales. This variability occurs as a result of the heart’s responsiveness to its environment. The more robustly and quickly the heart responds, the healthier it is.
HRT seeks to measure how quickly and vigorously the heart rate reacts in response to a single premature beat from the ventricle — a premature ventricular contraction (PVC). Normally after a PVC, the heart rate speeds for a few beats, and then slows back to baseline over the next 10 beats. The healthy heart responds with a more intense rise in heart rate and a quicker return to baseline. Using simple measurements of heart rate from a standard 24-hour electrocardiogram (ECG) monitor, a propriety software program averages many of these responses and comes up with a measurement of turbulence onset and turbulence slope. Read more »
*This blog post was originally published at Dr John M*
March 4th, 2011 by Toni Brayer, M.D. in Health Tips, Research
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There are few medical conditions that people fear more than a stroke. We know that blood pressure control and lowering cholesterol levels reduces stroke risk. Now, thanks to a huge analysis from Italy published in the Journal of the American College of Cardiology, we know that higher dietary consumption of potassium is associated with lower rates of stroke and could also reduce the risk of coronary heart disease and total cardiovascular disease, too. What is even more remarkable is that the results apply to all parts of society and not just to specific “at-risk” subgroups.
Most doctors aren’t even aware of how important it is to eat potassium-rich foods. And what are these foods that have potassium? Surprise: It’s fruits and vegetables like bananas, tomatoes, oranges, apricots, most legumes, spinach, winter squash, avocado, kiwi, and cantaloupe. Actually, almost all fruits and veggies have moderate to high potassium content.
The researchers looked a number of well-done studies that included 247, 510 participants over age 30 and found that those patients with the higher potassium intake reduced their stroke risk by 21 percent. The Italian doctors say the protective effect of potassium against stroke is in part due to its blood pressure lowering effects and also due to other properties of the potassium mineral, such as the inhibition of free radical formation.
I’ve written before about the DASH diet, which also found that reduction of sodium and addition of fruits and vegetables to the diet is an effective way to control blood pressure. The DASH diet is high in potassium.
Think about it: Did you have five servings of fruits and vegetables today? Numerous studies have shown their life-prolonging benefits. This new study just adds to what we already know. I challenge all readers to keep a diet count and make sure you are eating five fruit and vegetable servings a day — every day — to help reduce your risk of stroke, cancer, and heart attack.
*This blog post was originally published at EverythingHealth*
March 3rd, 2011 by StevenWilkinsMPH in Opinion, True Stories
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We hear about stories like this all time: An elderly person falls and breaks something — a hip, a wrist, or an arm. Soon what once was a healthy, independent senior begins an inexorable downhill slide. Such is the case of my 89-year-old mother who recently fell and broke her wrist.
Turns out that 30 percent of people age 65 and older fall each year. Predictably, seniors with the following risk factors are more prone to falls:
- Using sedatives
- Cognitive impairment
- Problems walking
- Urinary tract infection
- Eye problems
- Balance issues
Similarly, when a person does fall, a cascading series of predictable clinical events occurs. It even has a name: “Post-fall syndrome.” This syndrome is characterized by things like fear of falling again, increased immobility, loss of muscle and control, lack of sleep, nutritional deficits, and so on. Seniors susceptible to falls also have higher rates of hospitalization and institutionalization.
What strikes me about falls among the elderly is that they are seemingly predictable events. And once a fall does occur, the consequences seem pretty predictable as well — enter post-fall syndrome. So if falls and their consequences are so predictable, why aren’t primary care physicians more proactive in terms of:
- Preventing falls?
- Treating post-fall syndrome?
In the case of my mother, her primary care physician and orthopedist were both very diligent at treating her episodic needs (i.e. her pain and broken bones). But little attention, if any, was given to assessing her long-term needs, such as nutrition, inability to do anything with her left hand (she’s left-handed), sensitivity to new medications (she never took drugs because they make her loopy), gait analysis, and depression counseling. Read more »
*This blog post was originally published at Mind The Gap*
March 2nd, 2011 by Jon LaPook, M.D. in News, Research, Video
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A new study finds that half of men in America are infected with the HPV virus. Dr. Jon LaPook reports on the growing concern that the virus in men could be responsible for an increase in head and neck cancers.
HPV Affects Half Of U.S. Men
A study out [yesterday] in The Lancet by Moffitt Cancer Center researcher Anna Giuliano, Ph.D., and her colleagues finds that 50 percent of men ages 18 to 70 in Brazil, Mexico, and the U.S. have genital infection with human papillomavirus (HPV). HPV is the virus that causes cervical cancer in women. It also causes warts and cancer of the genitals and anus in both men and women. Over the past several years, researchers have realized that the virus can also cause cancer of the head and neck.
Aimee R. Kreimer, Ph.D., of the National Cancer Institute, estimates that about 65 percent of the approximately 8,000 cancers of the tonsils and base of the tongue (oropharynx) seen in the U.S. in 2010 were from HPV infection; eighty percent of these are in men. The rates for HPV-associated cancers like these are increasing; for sites like the mouth and larynx that are associated with tobacco and alcohol use, the rates are decreasing (though still too high since too many people still smoke and abuse alcohol).
An infection rate of 50 percent for a virus that can cause cancer sounds scary. But knowing a few more facts about HPV helps put the risk in perspective. About 90 percent of men and women infected with HPV virus get rid of it on their own within about two years. There are many different strains of HPV — some that cause cancer and some that don’t. Only about 6 percent of men have genital infection with HPV 16 — the strain linked to more than 90 percent of cancers of the head and neck. And only about 0.6 percent of men have HPV 16 in specimens taken from their mouths; what percentage of those men go on to develop head and neck cancer is unknown. Read more »
February 26th, 2011 by PJSkerrett in Opinion, Research
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We all know that using a cell phone can stimulate the brain to work a bit harder. “Mr. Skerrett? This is Dr. LeWine’s office. Do you have a minute to talk about your test results?” or “Dad, a bunch of kids are going to Casey’s house after the dance. Can I go?” But a new study published in JAMA is making me wonder what the energy emitted by the phone itself — not just the information it delivers — is doing to my brain.
Here’s the study in a nutshell. Dr. Nora Volkow and her colleagues recruited 47 volunteers to have their brain activity measured twice by a PET scanner. Both times the volunteer had a cell phone strapped to each ear. During one measurement, both phones were turned off. During the other, one phone was turned on but muted so the volunteer didn’t know it was on; the other was left off. Each session lasted about an hour. The scans showed a small increase in the brain’s use of glucose (blood sugar) when the phone was on, but only in parts of the brain close to the antenna.
It was an elegant study. The researchers took pains to anticipate sources of error. They used a control (both phones off) against which to compare the effect of a “live” cell phone. They used cell phones on each ear, one on and one off, to see if the effect was localized. They muted the phone that was on to eliminate the possibility that any brain activation was due to listening to the sound of a voice coming through the phone’s speaker. So the result is probably a real one, not an artifact or measurement error.
What does this brain activation mean? No one really knows. As Dr. Volkow told NPR, “I cannot say if it is bad that they [cell phones] are increasing glucose metabolism, or if it could be good.” Read more »
*This blog post was originally published at Harvard Health Blog*
