Background Information | Benefits of exercise on Coronary Heart Disease (CHD)

What is Coronary Heart Disease?

Coronary heart disease is a leading cause of death worldwide and in the United Kingdom, with approximately 1 in 6 women and 1 in 5 men dying from the disease each year (Health Knowledge, 2006). CHD is also referred to as ischaemic heart disease (Bhf.org.uk, n.d.), this disease occurs as a result of the narrowing of the coronary arteries due to the build-up of fatty material, known as atheroma. The fatty deposits cause damage to the inner artery layer leading to atherosclerosis, which prevents oxygen rich blood to the heart muscle (Felman, 2019).

Atherosclerosis is caused by various lifestyle factors such as (nhs.uk, 2017):

Smoking
High cholesterol
High blood pressure
Diabetes
Obesity
Ethnicity
Sex (men develop CHD earlier than women)
Age (more likely to occur in older people)

Symptoms

A common symptom with CHD is angina (chest pain) which can extend to other areas of the body such as the arms and legs. These pain symptoms are most often triggered by physical activity or stressful situations (Felman, 2019).

Heart attacks (myocardial infarctions) are major symptoms and they can cause permanent heart damage which can be fatal. Acute or chronic heart failure can lead to fluid build-up in the lungs and cause breathing difficulties (nhs.uk, 2017).

Diagnosis

The initial check would be to take a blood test and see whether the patient’s history highlights any previous occurrences of CHD or related diseases and inspecting the patient’s lifestyle factors that may cause CHD ( nhs.uk, 2017).

CT and MRI scans can be used to diagnose CHD by checking calcium deposits, narrow arteries and blood clots.Electrocardiograms are carried out to check electrical activities and rhythm of the heart via electrical signals passed through the heart. This test enables a view of information on a previous or upcoming heart attack (Mayoclinic.org, 2018).

A complex but efficient method called coronary angiogram involves a special contrast dye being injected into the coronary arteries allowing blood flow to be seen, outlining narrow spots and blockages (Mayoclinic.org, 2018).

Treatment

Coronary heart disease can be treated through medication but in some instances may require surgery. Medications are mostly oral medications that are taken in tablet form. Examples of these are beta blockers, ACE inhibitors and calcium channel blockers.

Beta blockers like atenolol and propranolol work by reducing the blood pressure and heart rate of the patient (nhs.uk, 2019).

Angiotensin converting enzyme inhibitors such as ramipril and perindopril lower blood pressure (WebMD, n.d.).

Calcium channel blockers such as felodipine and verapamil widen the arteries and reduces hypertension (WebMD, n.d.).

Some medications are used via transdermal and nasal routes. For example, nitro-glycerine comes in the form of sprays, patches and tablets which widen the arteries.

For patients where medication alone is not sufficient, surgery is required. Laser surgery is carried out on the heart muscle to create small holes which eventually triggers the formation of new blood vessels which will allow blood flow (Felman, 2019).

Another surgery type is coronary bypass, where a blood vessel from the leg or inner chest wall artery is used to form a graft which allows blood to reach the heart by avoiding the blocked artery (Felman, 2019).

Angioplasty is an effective surgical method that involves a catheter being placed in a narrow artery with a deflated balloon which is then inflated. This pushes out fatty deposits against the walls, widening the artery. On some occasions a stent may be required to ensure the artery stays open (Felman, 2019).

Prevention

Coronary heart disease can be prevented through changes to various lifestyle factors before symptoms develop or once any symptoms are seen.

Consuming foods which are less in sugar, salts and saturated fats contributes to a healthy balanced diet (Mayoclinic.org, 2018).

Smokers can stop smoking as a precaution to preventing CHD as nicotine constricts blood vessels (Mayoclinic.org, 2018).

In addition to eating healthily, regular exercise can help maintain a healthy weight and to allow normal blood flow which is vital to stop CHD occurring (Mayoclinic.org, 2018). Exercise is an important component in maintaining a healthy weight which in turn makes the heart and blood system more efficient which prevents the risk of CHD (nhs.uk, 2017). There is a wide range of evidence from over 40 years that individuals who are constantly sitting have twice the risk of developing CHD compared to those who exercise regularly. Evidence has also shown 37% of deaths of CHD patients has been due to no exercise (Press, Freestone and George, 2003).

Exercise benefits

There is an inverse relationship between physical activity and CHD risk where the risk is lower in patients who exercise more. This was seen in a test on around 45000 men where exercise such as running, walking and weight training were associated with reduced CHD risk. The intensity of the exercise was also related to the reduction of CHD risk as there was an inverse association between overall intensity and CHD incidence (Tanasescu, 2002).

Physical activity has an effect on CHD risk as it directly affects the heart by increasing myocardial oxygen supply and improving myocardial contraction and electrical stability. Furthermore, exercise assists in increasing HDL levels and lowering LDL levels, lowering blood pressure, decreasing blood coagulability and increasing insulin sensitivity (Tanasescu, 2002).

As well as improving HDL and LDL levels of cholesterol, exercise improves the blood lipid profile and reduces triglyceride levels. Studies have shown that 45% of deaths from CHD in men and 47% in women are due to raised blood cholesterol levels (Press, Freestone and George, 2003).

Blood pressure is lowered by physical activity where more activity has led to greater reductions in blood pressure up to 11 mmHg and 8 mmHg in systolic and diastolic pressure respectively. Approximately 13% of CHD deaths have been due to high blood pressure (Press, Freestone and George, 2003).

Obesity has been suggested to increase the risk of CHD and exercising not only reduces blood clotting but also promotes body fat metabolism and increases metabolic rate which helps prevent obesity (Press, Freestone and George, 2003).

Diabetes is another factor that increases coronary heart disease and it has been discovered that women have a greater risk of CHD than men with type 2 diabetes. As exercising has shown to increase insulin sensitivity, blood glucose levels are reduced, and this reduces CHD risk. The same has also been seen amongst type 1 diabetic patients (Press, Freestone and George, 2003)

Research of exercising in patients who already have CHD has shown that the risk of death from CHD is reduced by 20% and is beneficial for those with NYHA class II and III heart failure (Press, Freestone and George, 2003).

Written by Lydia Sivanathan (17848425)

References:

Bhf.org.uk. (n.d.). Coronary heart disease (CHD). [online] Available at: https://www.bhf.org.uk/informationsupport/conditions/coronary-heart-disease [Accessed 4 Dec. 2019].

Felman, A. (2019). Coronary heart disease: Causes, symptoms, and treatment. [online] Medical News Today. Available at: https://www.medicalnewstoday.com/articles/184130.php#symptoms [Accessed 4 Dec. 2019].

Health Knowledge. (2006). Coronary heart disease. [online] Available at: https://www.healthknowledge.org.uk/public-health-textbook/disease-causation-diagnostic/2b-epidemiology-diseases-phs/chronic-diseases/coronary-heart-disease#CHD [Accessed 4 Dec. 2019].

Mayoclinic.org. (2018). Coronary artery disease – Diagnosis and treatment – Mayo Clinic. [online] Available at: https://www.mayoclinic.org/diseases-conditions/coronary-artery-disease/diagnosis-treatment/drc-20350619 [Accessed 4 Dec. 2019].

nhs.uk. (2017). Coronary heart disease. [online] Available at: https://www.nhs.uk/conditions/coronary-heart-disease/ [Accessed 4 Dec. 2019].

nhs.uk. (2019). Beta blockers. [online] Available at: https://www.nhs.uk/conditions/beta-blockers/ [Accessed 4 Dec. 2019].

Press, V., Freestone, I. and George, C. (2003). Physical activity: the evidence of benefit in the prevention of coronary heart disease. QJM: An International Journal of Medicine, [online] 96(4), pp.245-251. Available at: https://academic.oup.com/qjmed/article/96/4/245/1528536 [Accessed 5 Dec. 2019].

Tanasescu, M. (2002). Exercise Type and Intensity in Relation to Coronary Heart Disease in Men. JAMA, [online] 288(16), p.1994. Available at: https://jamanetwork.com/journals/jama/fullarticle/195439 [Accessed 5 Dec. 2019].

WebMD. (n.d.). Heart Disease Treatment with Calcium Channel Blocker Drugs. [online] Available at: https://www.webmd.com/heart-disease/guide/heart-disease-calcium-channel-blocker-drugs#1 [Accessed 4 Dec. 2019].

WebMD. (n.d.). How do ACE Inhibitors Help Treat Heart Disease?. [online] Available at: https://www.webmd.com/heart-disease/guide/medicine-ace-inhibitors#1 [Accessed 4 Dec. 2019].