Coronary heart disease
a) The pathophysiology of coronary heart disease
Stephenson (2011) explains that there are two major important diseases of the arteries – one is arteriosclerosis which is a hardening of the arteries. Arteriosclerosis is a natural aging process where gradually the initial elastic tissue is replaced by firmer connective tissue, which in some instances can accumulate calcium. Such hardened vessels are unable to contract and expand and can restrict blood flow. The other, which is more important in coronary artery disease, is atherosclerosis. This is the build-up of a waxy plaque forming an atheroma on the inside of the arteries, but which also harden and weaken the arteries too.
Schematic representation of normal coronary artery wall (top) and development of atheroma (bottom). Grech(2003)
As shown on the diagram above, there are 3 layers to an artery wall. Kumar and Clak (2009) describe how the intima, is made up of a layer of endothelial cells which secrete a variety of substances such as nitrous oxide and endothelin. Nitric oxide has a dual purpose of a) keeping the artery’s inner lining smooth and slippery preventing white blood cells and platelets sticking to it and b) nitric oxide widens the artery to allow more blood to flow through it. The media is the middle layer of the artery wall and that is composed mainly of smooth muscle cells which increase or restrict the flow of blood in an artery.
Tortora and Grabowsji deacribe how excess LDL cholesterol leaves the bloodstream and lodges in the artery walls. Problems start occurring when free radicals interact with the LDL and oxidise it, changing its chemical form (to OxLDL) and so becoming toxic. This injures the endothelial layer, causing endothelial dysfunction and the cells can’t preform their normal tasks such as producing nitric oxide normally. The endothelial cells in response to this attack release chemical messengers called cytokines which attract specialised white blood cells (T-lynphocytes and macrophages) . These scavenger cells engulf the oxidized LDL which enlarges them into fat-laden foam cells. The first sign of artherosclerotic lesions in childhood are these arterial fatty streaks.
Progression of atheromatous plaque from initial lesion to complex and ruptured plaque. Grech(2003)
Kumar and Clak (2009) further explain that the toxic LDL injures the foam cells and many die, releasing a fatty gruel which provokes further round of inflammation as more macrophages are attracted to the site, continuing the cycle. The artery becomes inflamed and the smooth muscle cells in the media enlarge and proliferate and so thicken the endothelium. Collagen is produced in larger and larger quantities. The cholesterol plaque causes the muscle cells to enlarge which over time can become hardened by connective tissues and calcium, forming a fibrous cap covering the lipid core. All this substance causes a narrowing of the artery and reduces blood flow. By impairing or obstructing normal blood flow, atherosclerotic build-up causes myocardial ischemia. As can be seen in the above diagram this whole process takes about 40 years before it results in cardiovascular symptoms. In addition to narrowing the artery atheromas cause stiffening and distortion of the larger vessels and the affected blood vessels have an irregular and fragile lining which can stimulate the clotting process so that small blood clots form in these places. Small clots are more likely to break free and lead to major problems such as thrombosis and embolism which result in the infarction or death of tissues.
b) Why Marie is at particular risk of developing coronary heart disease
Unmodifiable risk factors Lifestyle risk factors Lifestyle protective factors
Age • High levels of saturated fats and trans fatty acids in the diet • Polyunsaturated and monounsaturated fats
Gender • Smoking • Fish oils
Positive Family history • Sedentary lifestyle • Regular moderate physical activity
• Overweight and Obesity • Flavonoids
• Alcohol intake greater than 4 units per day • Moderate alcohol intake
• Diabetes mellitus • Garlic
• Diet low in antioxidants • Diet rich in antioxidants
• Social causes of stress • Vitamins AC and E
• Excess salt in diet
Slightly modified diagram from CICM CMS Disk additions from NHS(1)
Family history – Marie’s mother had a heart attack. The susceptibility to developing heart attacks can be inherited, especially from a close family relative like your mother, and so Marie is at greater risk than average.
Marie is at an age now, post-menopausal , where the risk factor difference between men and women has levelled out. The risk of developing CHD increases with age and Marie is now 67.
Marie has Type 2 diabetes. This is the type of diabetes which can often be controlled by diet, exercise and weight loss. Diabetes is one of the major risk factors for heart disease and stroke. People who have diabetes are much more likely to develop heart disease and stroke than people who do not, due partly to the effect of the high sugar levels on the walls of the blood vessels, but also due to the fact that diabetics often have raised blood lipid levels. We don’t know the full circumstances of Marie’s life, but her husband says that she doesn’t really look after herself and so we might therefore consider that Marie might not be managing her diabetes as well as she might and so the risk of damage to the blood vessels from both atherosclerosis and arteriosclerosis will increase.
High blood pressure – Marie also has high blood pressure. We are not told what medication she is on for hypertension, but perhaps she is not managing it as well as she could be? Uncontrolled high blood pressure is an important risk factor in coronary heart disease, heart attacks and strokes and the higher the pressure, the higher the risk. Hypertension probably triples the risk of death from CHD.
Unhealthy eating – Her husband says that Marie doesn’t eat healthily. She possibly samples the pastry dishes that she bakes for others. It is necessary for someone with diabetes to really be in control of their diet otherwise the risks are compounded.
Stress – Her husband says that Marie looks after other people and not after herself. Although this may be giving her pleasure, it may also be contributing to the stresses of her life. Also I’m assuming she also looks after her husband, who is not a young man and not in the best of health. Stress is known to increase the risk of CHD.
So Marie has many factors which are contributing to her higher than average risk of developing CHD. However having more than one of these risks factors will multiply your overall risk factors for heart disease and stoke significantly.
Today also Marie walked in to the clinic on a very cold day
c) Questions which a GP might ask
Symptoms in the elderly may be different to those laid out in the table below. In the elderly the symptoms are milder and sometimes all they feel is a sudden onset of breathlessness or palpitations. This can be a warning sign of angina or heart attack.
Questions Expected answer(s) for a patient with:-
Stable angina Myocardial infarction
Nature of the pain
(crushing, burning, aching,
stabbing) Intense cramping pain Heavy, Tight, Gripping.
Can also be similar to indigestion or heartburn Crushing, Thick band around the chest. Sustained, intense.
Location /radiation of the pain
Centre of chest, Up neck, jaw and down one or both arms Centre of chest, tends to radiate to the left shoulder
Severity of pain (out of 10) Variable – 9 or 10, but can be painless in the elderly Variable but 9 or 10
Onset. What was the patient doing at the time? Exertion of some kind. Cold. Emotional Stress. Eating(large meal) Can be at rest. No discernible pattern
How quickly did the pain begin Begins slowly and gets worse Can happen after worsening angina or can happen without notice, spontaneously
Changes in pain over a period of time / duration Generally improves within 15 minutes May last longer than 15 minutes
What made the pain worse Anything that puts the heart under load eg exercise., Stress
What relieved the pain Rest, Glyceryl nitrate usually tablet or GTN Spray Less likely to be relieved by rest
Associated symptoms Feeling of impending doom or emotional sense of deep fear. Cold sweat, May vomit . Shortness of breath.
The above information collated from Stephenson (2011)
d) Warning features of angina and heart attack
When Marie first arrived at the clinic, it was possible that she was just having a bout of angina from her early morning exertions in the cold. The initial symptoms of angina and a heart attack are similar and warning features are:
Central chest pain which is related to exertion, eating or the cold – Marie has this.
The pain is heavy, gripping rather than sharp or stabbing. It can radiate to the neck or down the arms – Marie has severe pains in her arm and chest
In unstable angina or heart attack all the symptoms are the same and can also come on spontaneously without exertion etc. However, with stable angina, resting the patient out of the cold environment that she was in should give the body time to recover and the GTN spray should ease the symptoms. (The current medical advice is to spray 3 times at 5 minute intervals over a 15 minute period and then call an ambulance, unless the symptoms are getting more severe in which case call straightaway).
Marie is resting and has taken the GTN spray, but her symptoms are not subsiding. Stephenson (2011) describes how iIn unstable angina the symptoms are less likely to be relieved by rest.
She is distressed, breathless and sweating profusely. In the elderly there are often fewer symptoms of a heart attack and sometimes the only symptoms experienced can be the sudden onset of breathlessness or palpitations. She is also feeling very nauseous and vomiting is one of the warning signs of unstable angina. Clearly Marie is exhibiting some of the signs of unstable angina or a heart attack and the safest precaution is to call an ambulance in such circumstances. Her age, medical and family history reinforce such a decision.
e) Hospital investigations of coronary heart disease
The NHS (2) describe a coronary angiography as a test that can be used to identify whether your coronary arteries are narrowed and determine how severe any blockages are. A catheter (a thin, flexible tube) is passed into a vein or artery in your groin or arm and using X- ray images it is guided to heart or arteries.
1. Catheter in arm, 2. Catheter in groin, 3. Heart. NHS(2)
A special fluid (called a contrast medium or dye) is injected into the catheter to highlight the arteries supplying blood to your heart. A number of X-ray images (angiograms) are taken that will highlight any blockages and as the fluid that is injected is visible on the X-rays it will reveal if any of the blood vessels are narrowed or blocked, and if the heart is working as it should be.
Coronary angiograms are generally considered safe procedures according to NHS (2). However there are some risks, with minor risks including: allergy to the contrast dye used, bleeding under the skin at the wound site (haematoma), bruising. In very rare cases, a more serious complication can occur. These include: death, heart attack or stroke. The risk of one of these serious complications occurring is estimated to be around 2 in 1,000 and is usually the result of a serious underlying heart disease.
An echocardiogram uses sound waves to produce images of the heart. The images from an echocardiogram can be used to identify various abnormalities in the heart muscle and valves as it will not only reveal the outline, but two- dimensional (2-D) Echo is capable of displaying a cross-sectional “slice” of the beating heart and also show up the four chambers, the valves, the major blood vessels that exit from the left and right ventricle ,and also the speed of flow and pressure of blood within the heart using the same principle as with the Doppler probe. It can be a useful test the precise assessment of valvular conditions and heart failure and is routinely used to assess people with heart valve problems or congenital heart disease. It is a very safe tool.
f) TCM interpretation of Angina and Complementary therapies for treating angina
Stephenson (2011 explains how the intense pain of angina would most likely be diagnosed as Heart Blood Stagnation with an underlying Stagnation of Qi and Blood. The root cause of angina is often atherosclerosis and so that the patient might also exhibit some signs of non-substantial Phlegm and a deficiency of Zong Qi, the Qi that supports the health of the vessels.
One complementary therapy that Marie might receive is acupuncture. There have been some trials showing that acupuncture treatment is effective for angina.
Richter et al (1991) describe how in a Swedish trial 21 patients with stable effort angina pectoris were randomized in a crossover study to 4 weeks traditional Chinese acupuncture or placebo tablet treatment. All of the patients had a history of at least five anginal attacks per week despite intensive conventional medical treatment. As well as their conventional medicine, acupuncture treatment was given three times per week, which led to a 40% reduction in the number of anginal attacks. The researchers also observed that the patients were able to exercise for longer before the onset of pain. A life quality questionnaire confirmed improved an improved feeling of well-being. The conclusion was that acupuncture was beneficial even for patients with severe, medically intensively treated angina pectoris.
Marie could continue to take her normal medication as well as undergo acupuncture treatment which would act as a complimentary therapy.
Another complementary treatment that can be helpful for Angina is Naturopathy. According to Trattler (1987) Naturopaths feel that diet is an important way of preventing cholesterol from obstructing the arterial walls and advise dietary changes to bring this about. After a dietary regime has been put into practice, treatment will then focus on relieving stress. Relaxation and breathing exercises will be proscribed as well as an exercise regime to help overall fitness. Such a regime is more for an active person who wishes to get involved in the management of their health.
CICM (2010), CMS Disk
Grech, E.D (2003) ABC of interventional cardiology -Pathophysiology and investigation of coronary artery disease BMJ2003;326:1027
Kumar P and Clark M L (2009) Clinical Medicine (Kumar and Clark’s Clinical Medicine). 7th Edition. Spain: Saunders Ltd
NHS web site (1) http://www.nhs.uk/Conditions/Angina/Pages/Causes.aspx accessed 14/4/12
NHS web site(2) accessed 14/4/12
Richter, A, Herlitz,J. Hjalmarson, Å. (1991)Effect of acupuncture in patients with angina pectoris European Heart Journal (1991) Volume 12, Issue 2 Pp. 175-178.
Stephenson, C (2011) The Complementary Therapist’s Guide to Conventional Medicine, 1st Edition, Oxford: Churchill Livingstone
Trattler, R (1987) Natural Healing, Wellingborough, Thorsons
Tortora, G J and Grabowsji, S R (1992) Principles of Anatomy & Physiology. 7th Edition. New York: Harpercollins College Div.
Waugh A and Wilson K J W (2006) Anatomy and Physiology in Health and Illness 10th edition Oxford: Churchill Livingstone