The lowdown on low-calorie sweeteners

An advisory from the American Heart Association says beverages with low-calorie sweeteners are an acceptable way to curb the use of regular sugar-sweetened beverages, which are linked to diabetes, obesity, high blood pressure, and other risks for heart disease. Short-term studies suggest that replacing regular sugary soda with diet soda helps people control their weight, while longer-term studies are less definitive. But two large, long-running Harvard studies found no increased risk of obesity and diabetes among people who regularly drank beverages with low-calorie sweeteners. (Locked) More »

Understanding ejection fraction

An ejection fraction is the percentage of blood that leaves the heart each time it contracts. The most common way to measure the ejection fraction is with an echocardiogram. A normal value is 55% to 65%. (Locked) More »

Strategies for sleep apnea

Obstructive sleep apnea, which often causes loud snoring and daytime sleepiness, is closely linked to cardiovascular problems. The gold standard treatment, called positive airway pressure, can be challenging for people to use. Tips for using the bedside machine may help people use the treatment more consistently. These include making sure the mask fits properly and treating nose, mouth, or throat discomfort caused by the treatment. (Locked) More »

Heartburn vs. heart attack

During your regular after-dinner walk around the neighborhood, you feel a painful sensation in the center of your chest. Could it be your heartburn flaring up again, or something more serious? Heartburn is a common symptom of gastroesophageal reflux disease (GERD), often called acid reflux. Acid from the stomach bubbles up into the esophagus, causing a painful burning just behind the breastbone. Not surprisingly, it's often mistaken for a heart attack. In fact, of the over eight million emergency room visits for chest pain each year, severe heartburn accounts for over half the cases in which actual heart problems are ruled out. Chest pain caused by insufficient blood flow to the heart (angina) or a heart attack is often described as a feeling of tightness, constriction, or pressure, rather than a burning sensation (see "Heartburn or heart attack?"). But it's not always easy to tell the difference. "Chest discomfort brought on by exercise is more likely to be a heart-related problem," says Dr. Michelle O'Donoghue, cardiovascular specialist at Harvard-affiliated Brigham and Women's Hospital. But you can also have angina that's not related to physical activity, she notes. If you have any symptoms you're not sure about, see a doctor. And call 911 if you feel chest tightness, have trouble breathing, break into a sweat, turn pale, or become very weak. More »

What to expect during an exercise stress test

Exercise stress tests, also known as treadmill tests, are done mainly in people with symptoms suggestive of heart disease. That usually means stable angina, or chest pain that occurs in predictable patterns during physical activity. The test uses an electrocardiogram to record the heart’s electrical activity while a person walks on a treadmill that gradually increases in speed and incline. Changes to the ECG can signify blood flow abnormalities caused by blockages in the heart’s arteries or other problems in the heart. More »

Rethinking low-dose aspirin

 Image: © dszc/Getty Images It costs just pennies per pill, doesn't require a prescription, and may be lifesaving for some people. But daily low-dose aspirin doesn't make sense for everyone. Now, three major studies that examined the benefits and risks of this widely used drug may alter the advice about who should take aspirin. "Aspirin remains a cornerstone of treatment after a heart attack or stroke. But the question of whether people with a low to moderate risk of heart disease should take aspirin is a really important one," says Dr. Christopher Cannon, a cardiologist at Brigham and Women's Hospital and professor of medicine at Harvard Medical School. Tens of millions of people in the United States fall into that low-to-moderate-risk category. But until now, there weren't many large trials that included those people, he notes. (Locked) More »