Mayo Clinic Health Letter: Highlights from the July Issue

ROCHESTER, Minn., Monday, July 19th 2010 [ME NewsWire]:

(BUSINESS WIRE)-- Here are highlights from the July issue of Mayo Clinic Health Letter. You may cite this publication as often as you wish. Reprinting is allowed for a fee. Mayo Clinic Health Letter attribution is required. Include the following subscription information as your editorial policies permit: Visit www.HealthLetter.MayoClinic.com for subscription information.


When the Heart Skips a Beat -- Worry or Not?


ROCHESTER, Minnesota -- Almost everyone feels occasional heart palpitations -- a change in the heart’s rhythm. Palpitations range from what feels like a skip, flip or bump in the heart’s rhythm to a sustained, racing heartbeat.


The July issue of Mayo Clinic Health Letter provides an overview of heart palpitations, including when emergency care is needed, what diagnostic tests are used and common triggers.


Most often, heart palpitations are harmless, but not always. Palpitations can be a sign of an underlying serious problem such as heart disease, an overactive thyroid gland or anemia. Rarely, tumors can produce certain hormones that can cause heart palpitations.


Emergency care is recommended when palpitations are accompanied by chest pain or fainting, or if they involve a racing heart that doesn’t slow to a normal pace within about 20 minutes.


Palpitations, along with light-headedness, shortness of breath or a feeling of dizziness, or a racing heart that returns to normal on its own, are not considered medical emergencies but should be checked out with a physician.


To determine the underlying cause of palpitations, diagnostic tests might include a blood test to check for health concerns and a chest X-ray or echocardiogram to view the structure and function of the heart. An electrocardiogram (ECG) recording of the heart is generally recommended, too. Some patients are given ECG monitors to wear at home for one to three days in the hope of recording the heart during a palpitation episode.


Treatment varies greatly depending on the underlying cause of the palpitations. A doctor may also suggest ways to address possible palpitation triggers that can include:

* Stress, anxiety or panic


* Strenuous exercise


* Caffeine, nicotine and alcohol


* Any medication or supplement that acts as a stimulant, such as cold medicines containing pseudoephedrine, certain asthma medications or diet pills


* Fever


* Hormone changes associated with menopause


* Dehydration


* Thyroid abnormalities


MicroRNA -- A Switch that Determines Cell Behavior and Holds Answers on Disease, Prevention, Treatment


ROCHESTER, Minnesota -- Thousands of research studies are under way to better understand microRNA -- short for micro ribonucleic acid. These tiny genetic strands may play a role in identifying, treating and possibly preventing many diseases, according to the July issue of Mayo Clinic Health Letter.


MicroRNA acts like a switch that changes cell behavior. Different microRNAs are in each tissue of the body. For instance, what makes liver cells unique is, in part, their expression of a particular microRNA that influences which protein is produced.


About 1,000 distinct human microRNAs have been identified. Each can influence and regulate expression of hundreds of genes that determine a major change for the cell, such as whether it lives or dies, multiplies rapidly or develops into bone, muscle or another type of cell.


MicroRNA is a relatively new discovery. Scientists have been aware of its role for about 20 years, and there is still much to be learned. Scientists hope that microRNA research might eventually lead to improved diagnosis, more accurate predictions of disease outcomes and new treatment and medication options with fewer side effects.


Diseases being studied include:

* Heart failure -- MicroRNAs associated with this disease process may eventually tie into innovative therapeutic approaches.


* Alzheimer’s disease -- Studies have linked survival of brain cells (neurons) to their ability to produce microRNAs. Neurons incapable of doing so slowly die.


* Hepatitis C virus -- This virus “hijacks” certain microRNA to make copies of the virus within liver cells. Work is under way to develop a treatment that might keep the microRNA away from the virus.


* Schizophrenia -- Researchers are looking at possible associations between microRNA and this severe psychiatric disorder.


* Cancer -- Scientists have used microRNA to destroy liver cancer cells without harming healthy liver cells. Researchers have discovered a correlation between certain microRNAs and aggressive prostate cancer.


Meningioma -- Brain Tumor that May Not Need Treatment


ROCHESTER, Minnesota -- Meningiomas, the most common type of brain tumors, are rarely cancerous and may not require treatment. The July issue of Mayo Clinic Health Letter offers an overview of this brain tumor that is usually benign.


Meningiomas account for about 25 percent of primary brain tumors, those that originate in the brain. They are formed from the cells that provide a protective coating (meninges) that lines the outer surface of the brain and spinal cord. They typically grow outside brain tissue and rarely grow into the brain. The cause is unknown.


Symptoms: Meningiomas easily can go unnoticed, with no signs or symptoms. They may exert pressure on the brain and cause symptoms that can include vision changes, seizures, loss of hearing, weakness in the arms or legs or changes in balance.


Diagnosis: Diagnostic imaging -- particularly MRI -- is useful to identify the size and location of the tumor. On an MRI scan, meningiomas have a very characteristic appearance. Because many meningiomas don’t cause symptoms, they often are detected during imaging for some other, unrelated purpose.


Treatment: Ninety percent of meningiomas are benign, slow-growing tumors. If no bothersome symptoms are present, periodic monitoring for changes may be all that’s needed.


When meningiomas are causing symptoms, growing rapidly or are cancerous, several treatment options are available. The tumor can be removed during surgery. Depending on the location, removing the entire tumor may not be possible. When that’s the case, another step in treatment may be radiosurgery or radiation therapy.


In stereotactic radiosurgery, narrow beams of radiation are directed simultaneously at a small tumor, usually no bigger than an inch. Another approach is radiation therapy over a period of weeks. Radiation therapy is considered when tumor removal isn’t complete or surgery is not possible.


Overall, treatment outcomes are good for benign meningiomas after complete surgical removal. Tumors that can’t be totally removed due to their location are more likely to recur. However, in those cases, when radiotherapy or radiosurgery is done in combination with surgery, recurrence rates also are low.


Mayo Clinic Health Letter is an eight-page monthly newsletter of reliable, accurate and practical information on today’s health and medical news. To subscribe, please visit www.HealthLetter.MayoClinic.com.


About Mayo Clinic


For more than 100 years, millions of people from all walks of life have found answers at Mayo Clinic. These patients tell us they leave Mayo Clinic with peace of mind knowing they received care from the world's leading experts. Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. At Mayo Clinic, a team of specialists is assembled to take the time to listen, understand and care for patients' health issues and concerns. These teams draw from more than 3,700 physicians and scientists and 50,100 allied staff that work at Mayo Clinic’s campuses in Rochester, Minnesota, Jacksonville, Florida, and Scottsdale/Phoenix, Arizona. These locations treat more than half a million people each year. To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news. For information about research and education, visit www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource for your general health information.


For media enquiries, please contact:
Mayo Clinic
Duska Anastasijevic,
507-284-5005 (days)
507-284-2511 (evenings)
newsbureau@mayo.edu