Ask Tufts Experts

What exactly is a stress test?

A stress test, or exercise tolerance test, is used to screen for heart disease, predict a person’s risk for a heart attack, follow up after angioplasty or bypass surgery, or determine a safe level of exercise for someone recovering from a heart attack. A person taking the test walks on a treadmill or pedals a stationary bicycle while wearing electrodes attached to an electrocardiograph, or EKG, machine, which records the heart’s activity. If the arteries to the heart are narrowed or blocked, blood/oxygen flow is reduced. That can cause a person taking the test to experience fatigue, shortness of breath, or chest pain as the speed or incline is increased. The readout from the EKG will raise a red flag, too, and usually further diagnostic tests will be called for.

Do grapes have the same protective effect against heart disease as red wine?

Compounds called phenols, which come from the skin of grapes and are present in red wine, appear to benefit the heart by acting as antioxidants that prevent the formation of artery-blocking plaque. However, it’s not so much the phenols in red wine as the alcohol that seems protective. Studies have consistently linked moderate consumption of all kinds of alcohol to a reduced risk of heart disease. Health experts define “moderate” as no more than two drinks per day for men and one per day for women. But non-drinkers should not take up drinking for health reasons.