Medical Health Encyclopedia

The effects of mental stress on heart disease are controversial. Stress can certainly influence the activity of the heart when it activates the sympathetic nervous system (the automatic part of the nervous system that affects many organs, including the heart). Such actions and others could theoretically negatively affect the heart in several ways:

• Sudden stress increases the pumping action and rate of the heart while at the same time causing the arteries to constrict, thereby restricting blood flow to the heart. A 2002 study suggested that such actions may be responsible for some incidences of acute stress that have been associated with a higher risk for serious cardiac events, such as heart rhythm abnormalities and heart attacks, and even death in people with heart disease.
• Emotional effects of stress alter the heart rhythms, which could pose a risk for serious arrhythmias in people with existing heart rhythm disturbances.
• Stress causes blood to become stickier (possibly in preparation of potential injury), increasing the likelihood of an artery-clogging blood clot.
• Stress appears to impair the clearance of fat molecules in the body, raising blood-cholesterol levels, at least temporarily.
• Chronic stress may lead to the production of certain immune factors called cytokines that produce a damaging inflammatory response, which is now believed to be responsible for injuries in the arteries that contribute to heart disease.
• Studies have reported an association between stress and hypertension (high blood pressure), which may be more pronounced in men than in women. According to some evidence, people who regularly experience sudden spikes in blood pressure caused by mental stress may, over time, developed injuries in the inner lining of their blood vessels. In one 20-year study, for example, men who periodically measured highest on the stress scale were twice as likely to have high blood pressure as those with normal stress.