Heart attacks, or myocardial infarctions (MI), occur when blood flow to a part of the heart muscle diminishes or stops. The person usually experiences discomfort or pain, shortness of breath, sweating, nausea and weakness.
Heart attacks are the result of blockage or spasm of the coronary arteries, the blood vessels that nourish the heart muscle. The attack may result in permanent damage to the heart muscle and patients generally require immediate treatment, ongoing medical and lifestyle management and, often, cardiac rehabilitation.
There are many risk factors for heart attacks including smoking, elevated cholesterol, high blood pressure and diabetes. But these are generally chronic conditions, so what tips the balance towards the actual attack?
Unfortunately, even patients who were already taking drugs to prevent some of this cascade of events experienced an increase in risk of first MI following these two triggers.
The information used in the study came from 200 centers in 52 countries. The almost 12,500 participants in the study had a mean age of 58. Three quarters of the participants were male. Researchers took into account whether a person used cardiovascular preventive medications prescribed by doctors to help decrease known risks of cardiac events, and the scientists also controlled for the sex of the patient, their history of smoking, diabetes mellitus, hypertension, obesity, angina, stroke, levels of stress, depression and amount of education.
The data revealed that both physical exertion and anger or emotional upset acted as triggers for heart attacks. And when they were experienced together, the risk of heart attack increased even more. The findings were similar worldwide.
The reason for this double ewhammy, the authors suggest, is that heavy physical exertion and emotional upset activate the sympathetic nervous system. This leads to secretion of stress hormones, the constriction (narrowing) of blood vessels, rises in heart rate and blood pressure. These all add up to increased demands on the heart muscle and on the heart's need for oxygen. All this can lead to the rupture of an atherosclerotic plaque that is present in the coronary artery system, causing blockage of a coronary artery and an acute heart attack.
Unfortunately, even patients who were already taking drugs — aspirin, beta blockers and blood pressure drugs — to prevent some of these cascading events had an increased risk of a first heart attack following these two triggers. The authors conclude that this shows that preventing heart attacks that are precipitated by external triggers may be challenging, despite the availability of medications.
This is one reason physical activity is so important for maintaining cardiac and general health. Rather than avoiding such activity based on this study, people need to strengthen their cardiovascular systems, and the authors stress that health care providers should continue to advise regular activity but caution patients against short term intense bouts of physical activity (such as shoveling snow during a basically sedentary winter) — especially when angry or upset.
Check with your health care provider about starting an appropriate exercise program. Meditation and other stress management techniques can also help keep angry emotional responses from getting the best of you.
The study is published in the journal, Circulation.