Dr Health-shared Official
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Diabetes and heart attack

Diabetes and heart attack

Those diagnosed with diabetes are at greater risks of cardiovascular disease. Cardiovascular disease is the disease of the heart and the blood vessels. The inability to control the blood sugar levels causes damage to both the large and small blood vessels in the body. A high blood sugar level causes carbohydrate molecules (known as sugars) to stick to the molecules that circulate around in the body in the blood vessels. This has a variety of effects but it importantly increases the amount of inflammation in the body. This aids a process known as atherosclerosis - the narrowing and hardening of the arteries. Atherosclerosis is an inflammatory process in which certain cell types move into the artery wall and begin a chemical process which changes its structure. This process leads to infiltration of the artery wall with fat-like substances which are then chemically changed and harden over time. The artery wall is then vulnerable to plaque formation in which the inner surface of the artery is broken and fissured – this means it is more susceptible to narrowing and blockage. There is a wealth of research into this process and certain medications are targeted at halting and reversing it. Narrowing of the arteries causes the blood pressure to increase as it becomes increasingly difficult to pump blood around the body. This in turn, causes more pressure on the vessel wall and further damages the artery wall. 

Diagram showing the progression of atherosclerosis, causing narrowing of arteries over time

The heart itself requires nutrients and oxygen to pump blood continuously around the body, this is supplied by blood vessels known as the coronary arteries. Narrowing of these vital arteries results in a reduction in the amount of nutrients and oxygen reaching the cells in the heart. When there is insufficient oxygen and nutrients then the heart muscle can diminish – a process known as ischaemic heart disease. A heart attack occurs when a part of the blood vessel becomes completely blocked and thus dramatically and quickly depriving the heart of nutrients and oxygen it needs – causing the cells in the heart to die. This is known as myocardial infarction (MI) and is irreversible.

Diagram illustrating what happens during a myocardial infarction, also known as a heart attack. The blood coronary arteries are unable to supply the cells in the heart with oxygen and nutrients required to function, thus causing causing the heart cells supplied by that artery to die.

Surviving a heart attack is time critical – the faster one gets treatment, the greater the chances of survival. The most common treatment for a MI is a procedure called percutaneous coronary intervention (PCI), where the narrowing of the arteries is widened by inflating a balloon like device (angioplasty) and a small mesh-like tube called a stent is inserted to keep the blood vessel open. However, even if the supply to the heart is re-established, since the damage to cells is irreversible, patients can develop further complications such as the inability to pump blood effectively (heart failure) as well as developing irregular heartbeat rhythms (arrythmia).

Find out more about heart attacks here. (Hyperlink heart attack page on Health Shared)