Heart Health Archive

Q . Can you explain exactly what "ejection fraction" means? And is there any way to increase it?

A. Ejection fraction refers to the volume of blood that's pumped out of the heart's left ventricle each time it contracts. Contrary to what many people believe, a normal ejection fraction is not 100%. Even a healthy heart pumps out only about half to two-thirds of the volume of blood in the chamber in one heartbeat. So a normal ejection fraction lies somewhere in the range of 55% to 65%.

Q. My cardiologist told me to take clopidogrel for a year after I received a stent. Now the year is up. I haven't had any bleeding problems. Should I keep taking it?

A. In addition to aspirin, doctors routinely prescribe clopidogrel (Plavix) for people who receive stents, the tiny metal mesh tubes placed in clogged blood vessels to improve blood flow. This medication stops blood components called platelets from clumping together and forming clots. The current guidelines generally recommend that people take the drug for a year. This advice assumes they don't have any side effects such as unusual bleeding, which can show up as severe nosebleeds or blood in the urine or stools. However, these guidelines are still evolving. Experts are currently reviewing new findings from large studies on the benefits and risks of taking clopidogrel and similar drugs for extended periods of time.

New findings may help allay fears about sports-related heart death.

Rates of high blood pressure, diabetes, and heart disease vary among people of different backgrounds.

Summer's heat, humidity, and smog may be tough for people at risk of heart disease.

Cardiopulmonary resuscitation (CPR) not only saves lives, it may also help survivors of cardiac arrest recover well enough to return to work, according to a study in the May 12, 2015, issue of Circulation.

Researchers studied more than 4,300 people in Denmark who were employed before they suffered a cardiac arrest. In cardiac arrest, the heart suddenly stops working. More than 75% of survivors who had a cardiac arrest outside a hospital were able to return to work in a median time of four months. Those who received CPR from a bystander were nearly 40% more likely go back to work compared with those who didn't get CPR. The chest compressions given during CPR keep blood circulating to the brain, minimizing brain damage caused by a lack of oxygen.

Unless you have symptoms of a heart problem, taking a cautionary look under the hood is unlikely to help—and could even be harmful.

Many previous studies of adults of all ages have found that "moderate" drinking—one or two drinks per day for men and one drink per day for women—seems to protect against getting heart disease. A recent Harvard study challenges this notion, at least among older adults. The findings, published in the June 2015 issue of Circulation: Cardiovascular Imaging, suggest that even moderate amounts of alcohol are associated with heart damage among adults older than age 65. Researchers correlated weekly alcohol consumption among more than 4,400 seniors (average age 76) with the size, structure, and motion of the heart. The more people drank, the more researchers saw changes on images showing the heart's structure and function. This could mean that any alcohol intake may put older adults at a higher risk of developing heart problems, such as cardiomyopathy (which can lead to heart failure), a condition long associated with heavy drinking.

Image: Thinkstock

Now we have a better tool to calculate your chance of a brain attack if you've been diagnosed with afib.

Atrial fibrillation (afib) is among the most common heart rhythm irregularities. During a bout of afib, the usually rhythmic contractions of the heart muscle's upper chambers (the atria) are replaced by an ineffectual quiver that does not completely move blood out of the heart chamber. As a result, blood can stagnate and form clots. These clots can then travel to the brain and cause an ischemic stroke.

Some research has suggested that older people who take blood pressure medications may be prone to falls, perhaps because the drugs make them dizzy or lightheaded when they stand up. But a new study in the May 2015 Hypertension found no increased risk of falls in people taking blood pressure drugs.

For the study, nearly 600 people with chronic high blood pressure reported their falls to researchers via mail-in postcards and phone calls. Almost half of the participants, whose average age was 78, reported one or more falls during the yearlong study. Neither standard nor high doses of blood pressure drugs were linked to falls. In fact, people who took two commonly prescribed types of blood pressure medications—ACE inhibitors and calcium-channel blockers—had a lower rate of falling compared with people not taking those drugs. Given the known benefits of treating high blood pressure in older people, the authors say, withholding blood pressure medication for fear of causing a fall may not make sense.