Ischaemia is a reduction in blood flow, and Ischaemic heart disease is characterized by a reduction in blood flow to the heart muscles. The main cause of Ischaemic heart disease is coronary artery disease. Conditions such as high blood pressure, high cholesterol, diabetes, and lifestyle choices such as smoking, unhealthy diet, and lack of exercise can worsen this condition.
How coronary artery disease causes Ischaemic heart disease
Coronary artery disease also commonly known as atherosclerotic heart disease is a build up of plaque in the coronary artery. The coronary artery supplies the myocardium with oxygen via blood circulation. The build up of plaque in this artery causes a partial blockage, and decreases the available oxygen supplied to the heart muscle. The progression of this disease directly results in Ischaemic heart disease.
Symptoms of Ischaemic heart disease
- Stable Angina: this is a pain experienced in the chest when mild force (example walking up a flight of stairs, or even walking briskly) is exerted. This is due to the atherosclerotic plaque build up in the coronary artery. When force is exerted the heart needs more oxygen to perform its functions. If there is a partial obstruction of the coronary artery, the heart has to do more work with less oxygen, and so pain is experienced on exertion.
- Unstable Angina: this is a rupturing of the atherosclerotic plaque obstruction that is found in the coronary artery. This can lead to the fat droplets traveling in the blood stream, which may lead to blockages elsewhere, for example the brain, thus causing a stroke.
- Heart failure: since the heart has to do so much work with reduced blood and oxygen flow, it may fail due to over exertion.
- Myocardial infarction: this is commonly known as a heart attack. A heart attack is an interruption in blood supply to the myocardium or heart muscle. This interruption causes the heart cells to die, thus resulting in a heart attack. The interruption in blood supply is most likely caused by the partial or in some cases total blockage of the coronary artery which supplies the heart with blood and oxygen.
Other conditions influencing Ischaemic heart disease
- High cholesterol: the build up of cholesterol in the blood, specifically low density lipoproteins (LDL’s) contributes greatly to coronary artery disease. This is a partial or full obstruction in the coronary artery and this causes Ischaemic heart disease.
- High blood pressure: an overall chronic increase in the blood pressure, causes an increase in the muscle mass of the heart, and the blood vessels. When the muscle mass of the heart increases, the amount of blood it is able to store and circulate decreases. If the blood vessels are thickened then their overall circumference decreases. This decrease, increases the pressure of blood going to the heart, but reduces the blood flow. Because the heart muscles are already thickened, and the left chambers are receiving less blood, and a reduced oxygen concentration, the two conditions combine to give an overall effect of reduced blood flow to the heart. This requires the heart to do more work with its limited resources.
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