The functioning of the heart is under the control of the autonomous nervous system. Thus, the heart continues to beat without taking a break and without asking us. It is this continuous process of cardiac output that enables nutrition and oxygen to be supplied to all the tissues of the body. The heart itself needs nutrition and oxygen from the blood. This means that while pumping out blood, the heart also must have a source of blood. This function is performed by the coronary arteries.
The function of the coronary arteries is to supply blood to the heart. This is an essential process as the heart muscle is a highly aerobic tissue. The myocardial cell is packed with mitochondria indicating the high rate of oxygen consumption in this tissue. Problems arise when the area available for blood flow is reduced as a result of plaque formation within the arteries. Plaque formation may lead to blocking of one or more of the coronary arteries. This may lead to myocardial infarction and heart attack which may turn out to be fatal. This phenomenon has been called cardiovascular disease.
Plaque formation is not peculiar to the coronary arteries. This can take place in other arteries as well. When this occurs in the arteries which supply the brain, such a situation has been described as cerebrovascular disease. Blocking of the cerebral arteries can lead to impairment of the cognitive functions including abstract thinking, reasoning as well as memory. Other cognitive functions include reading comprehension, conversational skill, attention, concentration, organization, planning, mental imagery, pattern recognition, perception, action, association and concept formation. Occasionally, cerebrovascular disease and Alzheimer’s disease may work together to increase the cognitive impairment.
What is bad for the heart is bad for the brain as well. Hypertension, high blood cholesterol levels and decreased glucose tolerance are factors which promote cardiovascular disease. Obesity is another important contributor. Chronic sleep deprivation also plays a part in the development of coronary heart disease. All these factors also contribute to the development of the cerebrovascular disease and therefore, contribute to cognitive impairment. Therefore, steps taken to improve the cardiovascular function also help to prevent deterioration of cognitive functions.