Stress and heart disease


How does stress cause heart disease?

Stress and heart disease has various aspects. Stress can lead to increase in risk factors for heart disease as well as precipitate symptoms in a hitherto silent heart disease. Most older persons have build up of plaques in the blood vessels of the heart (coronary arteries). When there is a sudden severe stress, heart rate and blood pressure can shoot up. This can lead to increase of shear stress on the fat plaques in the blood vessels of the heart. A small break may form in the covering of the plaque, exposing the inner cells. Blood components known as platelets adhere to these breaks in the inner surface of the blood vessels and initiate the formation of blood clots. Blood clots in turn block the flow of blood in the vessel, leading to damage of heart muscle known as heart attack.

Sudden stress can sometimes lead to a surge in the blood levels of certain hormones like adrenaline. These contribute to the surges in blood pressure and heart rate. In addition this can upset the heart rhythm leading to life threatening rhythm disorders (cardiac arrhythmia) which can sometimes cause sudden stoppage of the heart (cardiac arrest).

Another manifestation of stress in the heart is the ‘broken heart syndrome’ or stress cardiomyopathy. This was initially described more in elderly females after sudden demise of their spouse. Part of the left ventricle (lower muscular chamber of the heart) becomes enlarged, giving it the name apical ballooning. This occurs in the absence of any blockage to the blood supply. Most of these cases do recover sooner or later. Stress cardiomyopathy has been described along with multiple other forms of stress other than bereavement.

Stress in general changes our life style and we may eat more of carbohydrate and fat. This has long term consequences like increase in body weight, blood sugar and blood pressure. These can further increase the chance of heart disease. Stress increases the blood pressure and blood sugar through hormonal influences even without a change in the diet pattern.

Risk factors for heart disease

bloom-in-the-wildernessWhat are the important risk factors for heart disease?

In general, when we talk about risk factors for heart disease, we tend to think about the most common variety of heart disease in adults – coronary artery disease. Risk factors for heart disease can be divided into modifiable and non modifiable ones. The non modifiable ones are age, gender, ethnicity and family history. The risk of coronary artery disease increases as age advances. So also, the risk is more in males compared to pre-menopausal females. A strong family history of premature heart disease is an important risk factor. Some races are more prone to coronary artery disease than others. Obviously, all these risk factors cannot be modified.

We are more concerned about the modifiable risk factors because that is where the individual and the community can act to reduce the risk. Important modifiable risk factors are smoking, high blood pressure (hypertension), high blood sugar (diabetes mellitus), high body weight (obesity), high levels of lipids in the blood (dyslipidemia) and chronic kidney disease. There are other risk factors as well, though not always checked for – increased levels of homocysteine, fibrinogen, C-reactive protein (CRP) and lipoprotein (a) [Lp(a)] in the blood. Though Lp (a) levels carry significant risk, there are no well established ways of reducing the risk due to it.