all cardiology stories

Sleeping your way to heart health

Wed, 11 Jul 2007 11:43:16 -0400

A new Harvard School of Public Health study indicates that there's more than just olive oil and red wine keeping heart disease rates down in Mediterranean countries. There's the naps, too.

A study that followed more than 23,000 people for six years showed that regular napping can cut deaths from heart disease by as much as 37 percent, providing a benefit in the same order of magnitude as that linked to lowering cholesterol, eating a healthy diet, or exercising.

Marathon running can damage a heart

Wed, 11 Jul 2007 14:56:27 -0400

Running 26.2 miles is not for the faint of heart.

Abnormalities in heart structure and function were found in men and women who ran the Boston Marathon in 2004 and 2005 by Harvard Medical School researchers.

For some 2,500 years, scientists have written about possible unhealthy outcomes of running for tens of miles when nothing is chasing you. But more and more people are doing it. In 2005, 382,000 runners completed a marathon, 80,000 more than in 2000. That has not led to a massive increase in heart attacks. In fact, Arthur Siegel, an assistant clinical professor of medicine, says the risk of dying from a heart attack is a scant one in 50,000 runners.

Research reveals how stem cells build a heart

Wed, 11 Jul 2007 16:11:35 -0400

Master cells that give rise to the three main cell types in a human heart have been discovered by Harvard Stem Cell Institute scientists working independently at two Harvard-affiliated hospitals. Together they found that a single progenitor stem cell differentiates into cells that cause a heart to beat, that make up its internal surface, and form its blood vessels.

The master cells arise during an early stage of embryo growth. As-yet-undiscovered signals then stimulate them to form the main building blocks of the heart, the first identifiable organ in the development of human life. Once started, that life-sustaining muscular pump beats more than 2,500 million times during an average lifetime.

Migraine auras and heart disease linked - risks high for women

Thu, 12 Jul 2007 10:01:49 -0400

Marsha T. saw the lights of pain coming. They flashed and zigzagged before her eyes. Her visual field shrank into a tunnel. A registered nurse, she knew what was next. In about 30 minutes, a familiar sharp, pulsating pain ripped through her head. Now 48 years old, she had been suffering from migraine headaches with aura since she was a teenager.

When the intense pain subsided, she relished the relief, but knew that the headaches would be back. Some 28 million people in the United States, most of them women, suffer from such repetitive, life-spoiling pain. And if that's not bad enough, evidence is accumulating that migraines are linked to an increased risk of major cardiovascular diseases, including stroke and heart attack.

Study says moderate drinking reduces men's heart attack risk

70652986 — Mon, 26 Mar 2007 07:10:56 -0400

Even as studies have consistently found an association between moderate alcohol consumption and reduced heart attack risk in men, an important question has persisted: What if the men who drank in moderation were the same individuals who maintained good eating habits, didn't smoke, exercised and watched their weight?

How would you know that their reduced risk of myocardial infarction wasn't the result of one or more of these other healthy habits?

A new study led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and the Harvard School of Public Health (HSPH) helps answer this question. Reported in the Oct. 23, 2006, issue of the Archives of Internal Medicine, the findings show for the first time that among men with healthy lifestyles, those who consumed moderate amounts of alcohol - defined as between one-half and two drinks daily - had a 40 percent to 60 percent reduced risk of heart attack compared with healthy men who didn't drink at all.

"This latest research speaks to how robust the link is between moderate drinking and heart attack risk," explains lead author Kenneth Mukamal, MD, MPH, an internist at Beth Israel Deaconess Medical Center (BIDMC) and associate professor of medicine at Harvard Medical School. "The fact that we found the association [between alcohol consumption and heart attack] to be just as strong in this tightly controlled group of men as we've found it to be in more general studies suggests that physicians should not avoid alcohol consumption as a topic for discussion when talking with patients about ways to reduce their risk of myocardial infarction."

Anger can break your heart

70652986 — Mon, 26 Mar 2007 06:28:18 -0400

Think about this the next time someone cuts you off in traffic or in a grocery store line: Anger can bring on a heart attack or stroke.

That's the conclusion of several studies at Harvard Medical School and elsewhere. One study of 1,305 men with an average age of 62 revealed that the angriest men were three times more likely to develop heart disease than the most placid ones.

Prostate treatment has risks

Thu, 12 Jul 2007 11:53:41 -0400

A treatment mainstay for prostate cancer puts men at increased risk for diabetes and cardiovascular disease, according to a large observational study published in the Sept. 20 Journal of Clinical Oncology.

"Men with prostate cancer have high five-year survival rates, but they also have higher rates of noncancer mortality than healthy men," says study author Nancy Keating, assistant professor of health care policy and of medicine at Harvard Medical School (HMS). "This study shows that a common hormonal treatment for prostate cancer may put men at significant risk for other serious diseases. Patients and physicians need to be aware of the elevated risk as they make treatment decisions."

Muscle cells grown into working heart cells

Fri, 13 Jul 2007 09:32:26 -0400

Muscle cells have been used successfully to restore life-sustaining rhythms to ailing hearts, a first step toward developing natural pacemakers. Placed in a tiny raft of collagen implanted into the hearts of rats, these cells survived for the entire lifespan of the animals.

"Our experiments provide proof that engineered tissue can function as an electric conduit in the heart and, ultimately, may offer a substitute for artificial (electronic) devices," says Douglas Cowan. He is an assistant professor of anesthesiology at Harvard Medical School who led a team of biologists, cardiologists, and surgeons at Children's Hospital Boston to create a biological substitute for the tissue that keeps the heart beating regularly.

New data finds defibrillator recalls to be common

70652986 — Mon, 26 Mar 2007 07:10:52 -0400

Data presented May 19, 2006 at the Heart Rhythm Society's 27th Annual Scientific Sessions finds that during a 10-year study period more than one in five automatic external defibrillators (AEDs) were recalled due to potential malfunction. The findings represent some of the first data available on safety and reliability of the devices, which are used to resuscitate victims of cardiac arrest.

"AEDs provide automated heart rhythm analysis, voice commands, and shock delivery and can be used by individuals with minimal training or experience," explains the study's lead author, William H. Maisel, M.D., M.P.H., director of the Pacemaker and Device Service at Beth Israel Deaconess Medical Center (BIDMC) and assistant professor of medicine at Harvard Medical School.

"As a result, widespread installation of AEDs has occurred in recent years." In fact, he adds, the annual number of the devices distributed between 1996 and 2005 increased almost 10-fold, from fewer than 20,000 to nearly 200,000.

"Public places such as airports, sports arenas and casinos are now routinely outfitted with AEDs and the U.S. Food and Drug Administration [FDA] has approved certain AED models for home use," he says. "Unfortunately, as AED use has increased, so too has the number of recalled devices."

Maisel and his colleagues reviewed weekly FDA enforcement reports to identify recalls and safety alerts (collectively referred to as "advisories") affecting AEDs. Enforcement reports are issued by the FDA to notify the public about potentially defective medical devices which may not function as intended. During the study period - beginning in 1996 and ending in 2005 - the authors found that the FDA issued 52 advisories involving either AEDs or critical AED accessories, affecting a total of 385,922 devices.

"The results showed that during this 10-year study period, more than one in five AEDs were recalled due to a potential malfunction," says Maisel.

Sense of security may be false with tried and true anti-inflammatories

70652986 — Mon, 26 Mar 2007 06:26:39 -0400

For all the tender joints and headaches they relieve and colon cancer they may prevent, the older nonsteroidal anti- inflammatory drugs (NSAIDs) raise another serious health risk.

The highly publicized danger of heart attacks and other cardiovascular side effects first discovered in randomized control trials of newer, selective NSAIDs are being found in the older agents, too.

A large prospective analysis from the Nurses' Health Study found elevated cardiovascular risk for daily and high doses of ibuprofen and naproxen, as well as acetaminophen, but not aspirin. Occasional use of the drugs, however, did not seem to pose any extra risk, said Andrew Chan, Charles Fuchs, and their co-authors in the March 28, 2006 Circulation.

Fatty foods feed heart attacks, researchers say

70652986 — Mon, 26 Mar 2007 06:26:30 -0400

Hold the french fries, doughnuts, and cookies, and save as many as 228,000 heart attacks and deaths from heart disease. That's the message from a team of researchers at the Harvard School of Public Health and Wageningen University in the Netherlands.

"Given the 1.2 million annual [heart attacks] and deaths from coronary heart disease in the United States, near-elimination of industrially produced trans fats might avert between 72,000 and 228,000 coronary heart events each year," the researchers report. Trans fats are also thought to play a role in unexplained sudden deaths and diabetes.

The major sources of trans fats include deep-fried fast foods, bakery products, packaged snack foods, margarines, and crackers. French fries, breaded fish burgers, breaded chicken nuggets, Danish pastries, pies, doughnuts, and cookies are the big offenders. Hamburgers, steaks, lamb chops, and dairy products contain only small amounts of natural trans fats so they don't make the list of "worsts." "The presence of beneficial factors in dairy and these meats may balance the effects of the smaller amount of trans fats they contain," according to Dariush Mozaffarian, lead author of the report that appears in the April 13, 2006, issue of the New England Journal of Medicine.

Ten to 19 percent of the coronary heart disease in the United States (120,000 to 228,000 heart attacks) could be averted by reducing the intake of trans fats, says Walter Willett, head of the research and Fredrick Stare Professor of Epidemiology and Nutrition at the Harvard School of Public Health.

According to the evidence that Mozaffarian, Willett, and their colleagues gathered from studies in the United States and Europe, the "adverse health effects of trans-fatty acids are far stronger on average than those of food contaminants or pesticide residues, which have in some cases received considerable attention. Furthermore, trans fats have no intrinsic health value above their calories."

The research team suggests that trans fats be reduced or eliminated from foods sold in stores, restaurants, and vending machines. Opposing arguments from food manufacturers and restaurants maintain that this would raise costs and lower taste. Recent experiences in Europe indicate that such concerns are overstated, say the researchers. They mention Denmark as a prime example. In that country, all oils and fats used in locally made or imported foods must contain less than 2 percent of industrially produced trans fats.

Exercise cuts risk of sudden cardiac death

70652986 — Mon, 26 Mar 2007 06:25:47 -0400

Exercise improves your health, but can you kill yourself with too much snow shoveling, yard work, jogging, or playing tennis?

"Despite all of the known benefits of exercise, there are also well-documented associations between acute episodes of exertion and sudden cardiac death," notes Christine Albert, an assistant professor of medicine at Harvard Medical School. "Although relatively rare, these deaths commonly occur in an unexpected fashion among those who appear quite healthy."

In the largest study ever done to get a better handle on this question, Albert and her colleagues followed the exertions of almost 85,000 women for 24 years, while keeping track of their hearts. The women, selected from an ongoing study of registered nurses known as the Nurses Health Study, were between 34 and 59 years old in 1986. From then until 2004, the women filled out questionnaires about how much time they spent jogging, running, bicycling, swimming, playing tennis or squash, and undertaking other activities that require moderate to vigorous exertion.

"To our knowledge, this analysis is the first to assess both the transient and long-term risk of sudden cardiac death associated with physical activity among women," says Albert, senior author of the study and also director of the Center for Arrhythmia Prevention at the Harvard-affiliated Brigham and Women's Hospital in Boston. Results of the study appeared in the March 22/29, 2006 Journal of the American Medical Association's theme issue on Women's Health.

The findings are encouraging. Out of almost 85,000 women, only nine died while doing yard work, housework, swimming, or physical therapy. To put this in numbers, as scientists always like to do: Their investigation covered 1.93 million person years of exercise and recorded only one death for each 36.5 million hours of exertion. In other words: Sudden cardiac death during exertion is an extremely rare event in women.

And there's still more good news. Regular exercise may significantly minimize this small risk, in both the short and long term.

Depression is bad for the heart

70652986 — Mon, 26 Mar 2007 06:25:04 -0400

Depression is more likely to break your heart than smoking or eating fatty food.

"Recurrence of cardiovascular events, including heart attacks, strokes, cardiac arrest, severe chest pain and other problems is more closely linked to depression than to high cholesterol, smoking, high blood pressure, or diabetes," according to a Harvard Medical School publication.

An article printed in the February 2006 issue of Harvard Mental Health Letter points out that patients who are depressed at the time of hospitalization for heart conditions "are two to four times more likely than average to die or to suffer further cardiovascular events during the following year."

And, just as sad, "about 50 percent of patients hospitalized with coronary heart disease have some depressive symptoms, and up to 20 percent develop major depression."

Depressed people who also are anxious add to their problems. According to one recent study, whereas depression doubles the risk of heart problems recurring, anxiety triples that risk.

It's not unusual for depressed people to suffer from anxiety. The two go together like pretzels and beer, so well that scientists have given it a new name - the Type D (for distressed) personality. Such people are chronically gloomy, worried, pessimistic, and lack self-assurance. The Harvard article mentions research in Belgium that found that "over a 10-year- period, patients in a cardiac rehabilitation program were three times as likely to die or have a second heart attack if they had this kind of personality."

Why does this happen? The Harvard publication notes that your mind and mood can push you into a chronic state of emergency readiness. Such people are ready to fight or run even when there's nothing to fight about or run from. In real emergencies, stress hormones rise, blood vessels constrict, your heart speeds up, appetite slackens, and it's harder to fall asleep. Inflammatory chemicals increase in the blood, which becomes stickier in anticipation of wounds that will need healing. When the scare ends, this red alert shuts down - unless you are seriously depressed or anxious.

Then, stress hormones stay jacked up. Inflammation may damage the lining of your arteries. Blood vessels become less flexible. The heart responds more sluggishly to internal signals telling it to slow down as the body's demands change.

It's hard to figure out exactly what happens. As the article notes, "cause and effect are difficult to disentangle in the relationship between depression and heart disease." Vicious cycles arise. Depression damages the heart and blood vessels, and that causes further depression.

Study provides first physiological evidence that insulin is critical for blood vessel formation

70652986 — Mon, 26 Mar 2007 06:24:49 -0400

For people with type 2 diabetes, the death rate from a first heart attack is two to three times the death rate of patients without the disease. Similarly, patients with diabetes and ischemic (reduced blood flow) heart disease have a much higher mortality rate than the general population.

International multi-center study confirms value of blood test to diagnose heart failure

70652986 — Mon, 26 Mar 2007 05:42:32 -0400

Congestive heart failure, which occurs when an impaired heart muscle cannot pump blood efficiently, is a growing health problem and major cause of cardiac death. The diagnosis of heart failure may be challenging because its symptoms can overlap those of other conditions.

Now a large-scale international study has demonstrated the usefulness of a blood test to confirm or exclude the diagnosis of acute heart failure in emergency room patients and shows that the test also can identify patients at a higher risk for death. The report from investigators in the U.S., the Netherlands, Spain and New Zealand also clarifies the importance of age-specific levels of a protein called NT-proBNP that definitively diagnose heart failure. The report appeared in the European Heart Journal.