How does stress cause heart disease? Cardiology Basics

How does stress cause heart disease? Cardiology Basics

Stress and heart disease have various aspects. Stress can lead to increase in risk factors for cardiovascular disease as well as precipitate symptoms in a hitherto silent cardiovascular disease. There is also a condition known as stress cardiomyopathy or broken heart syndrome, typically precipitated by an acute stressful event like loss of spouse in an elderly female.

Most older persons have build-up of atherosclerotic plaques in the coronary arteries. When there is a sudden severe stress, heart rate and blood pressure can shoot up due to sympathetic overactivity. There is also the release of stress hormones like adrenaline into the circulation.

The resulting hyperdynamic circulation can lead to increase of shear stress on the atherosclerotic plaques in the coronary arteries. Plaque rupture can occur in thin capped atheromas with more of fat content than fibrous tissue.

Platelets adhere to these sites of intimal rupture and initiate the formation of thrombus. Thrombus superimposed on an atherosclerotic plaque can lead to total occlusion of the coronary artery and lead to acute myocardial infarction.

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 and enhance the hyperdynamic circulatory state. Both sympathetic overactivity and release of stress hormones increase the myocardial contractility, thereby increasing the workload of the myocardium. Increase in myocardial workload can precipitate myocardial ischemia in those with significant coronary obstruction.

In addition, both sympathetic overactivity and release of stress hormones can increase the irritability of the ventricles. Enhanced ventricular ectopy, ventricular tachycardia and even ventricular fibrillation can occur with extreme stress. Other than the direct effect of neurohumoral activation, precipitation of myocardial ischemia can also indirectly increase the risk of life threatening ventricular arrhythmias.

Another manifestation of stress in the heart is the ‘broken heart syndrome‘ or stress cardiomyopathy. Takotsubo Cardiomyopathy and apical ballooning cardiomyopathy are other eponyms. Broken heart syndrome was initially described more in elderly females after sudden demise of their spouse.

In stress cardiomyopathy, apical regions of the left ventricle are hypokinetic and dilated, giving it the name apical ballooning cardiomyopathy. This occurs in the absence of significant coronary obstruction. The region of involvement does not conform to a single coronary territory as in acute myocardial infarction. The name Takotsubo cardiomyopathy is because of the resemblance of the angiographic appearance of the left ventricle to a Japanese octopus trap.

Most of these cases do recover sooner or later. Stress cardiomyopathy has been described along with multiple other forms of stress other than bereavement as well. Presentation of stress cardiomyopathy may be like acute myocardial infarction with ECG changes or as acute left ventricular failure with pulmonary edema. Diagnosis is usually made by the classical apical ballooning seen on echocardiography and absence of significant coronary obstruction on coronary angiography.

Stress in general changes our life style and we may eat more of carbohydrate and fat. High calorie food is often chosen when we are stressed as a sort of relief. This has long term consequences like obesity, hypertension and impaired glucose tolerance.

These can further increase the chance of cardiovascular disease. Stress can increase the blood pressure and blood sugar through hormonal influences even without a change in the diet pattern. So reducing stress in day to day life has a lot of beneficial effects. But it may not be that easy to achieve and may mean cutting down on one’s ambitions. Taking a break and relaxation techniques may be useful.