What is a heart attack?
A heart attack is medically known as a ‘myocardial infarction’ and is usually the result of underlying coronary heart diseases. They are described as a temporary or sudden change in blood circulation to the heart. Typically during a heart attack, the blood flow to the heart muscles is restricted, which results in the death of cardiac tissue due to being starved of oxygen (ischaemia). Heart attacks can cause subsequent life-threatening medical conditions such as congestive heart failure and cardiac arrests.
There are three types of heart attacks:
- ST-Segment Elevation Myocardial Infarction (STEMI): A type of heart attack where the arteries are completely blocked, and there is almost no blood supply to the heart.
- Non-ST Segment Elevation Myocardial Infarction (NSTEMI): A type of heart attack where the arteries are partially blocked and cause less damage than a STEMI.
- Coronary Artery Spasm (CAS): Also known as unstable angina or a silent heart attack. This type of heart attack is characterised by the arteries tightening such that blood flow stops, but without any blockage.
Heart attacks are caused by the gradual progression of coronary heart diseases. Over time, due to certain risk factors, fat can be deposited in between the cells of blood vessels in the heart. These fatty deposits in the arteries are called atheromas, which are characteristically ‘soft’ and sticky. Eventually, they transform into ‘firm’ atheromas (from deposits of calcium and other cell debris). Due to their brittle nature, they can rupture and release the semiliquid material from the central portion of the atheroma.1 Because this material contains thromboplastin (an enzyme that triggers blood clotting), a blood clot (thrombus) forms at the site, thereby restricting blood flow through the heart.1
There are two types of risk factors that can cause heart attacks: genetic (i.e. those that are inherited) or acquired (i.e. those that are related to lifestyle choices). Factors that contribute to heart attacks include:
- Hypertension: Also known as high blood pressure, which accounts for 50% of heart attacks, according to the British Heart Foundation.2 Arteries are naturally elastic in nature; however, high blood pressure causes them to lose their elasticity. As a result, they constrict, making them more prone to blockage by atheromas. Furthermore, hypertension puts additional arterial strain on patients previously diagnosed with cardiovascular diseases. Hypertension can be genetic (typically reported at the heritability of approximately 30% to 60%)3 or acquired.
- Low Levels Of High-Density Lipoproteins (HDL) Cholesterol: Low levels of HDL, also known as ‘good’ cholesterol in the blood, have been associated with cardiovascular disease; however, the causal relationship between heart attacks remains unclear.4 Low levels of HDL can be genetic (changes in the ‘ABCA1’5 or the ‘APOA1’6 genes) or acquired factors (due to poor nutrition).
- High Levels Of Low-Density Lipoproteins (LDL) Cholesterol: High levels of LDL, also known as ‘bad cholesterol’, aid in atheroma development by removing molecules in the blood (ex: nitric oxide) that widen the arteries.7 In the latter, they induce inflammation and blood clots.7 These collective events can trigger a heart attack. Low levels of LDL can be due to genetics (changes in the LDL receptor, APOB and PCSK9 genes)8 or an acquired factor (ex: poor nutrition).
- Type 1 & 2 Diabetes: Diabetes can damage the intricate structure of the arteries by disrupting the blood supply and damaging the surrounding tissue.9 This further effectuates inflammation and blood clots. Type 1 Diabetes is a genetic factor, whereas Type 2 Diabetes is an acquired factor.
- Other Genetic Factors: Menopause (the withdrawal of oestrogen has been linked to factors associated with cardiovascular diseases),10 obesity (due to having an excess of ‘bad’ cholesterol), and familial history of heart disease.
- Other Environmental Factors: Factors such as smoking, excessive alcohol consumption, an unhealthy diet, and sedentary and stressful lifestyles can contribute to heart problems.
The symptoms of heart attack vary amongst individuals, but the most common symptoms are: 11
- Chest pain (angina) that happens unexpectedly and doesn’t go away easily. The pain resembles pressure, heaviness, or squeezing in the chest. It can also feel like burning or indigestion.
- Pain that radiates from the chest to the jaw, neck, arms (usually the left, but can be both), back, and stomach.
- Feeling dizzy or lightheaded.
- Shortness of breath.
- Coughing or wheezing.
- Feeling sick (nausea) or being sick (vomiting).
- Feeling overwhelmed (anxiety or panic attacks).
If a heart attack is suspected by your doctor, you will be sent to the hospital immediately. You would typically be admitted to the acute cardiac care unit (ACCU), or the cardiac catheterisation unit, to confirm the diagnosis of your heart health.12 Some of the diagnostic tests that are conducted:
- Electrocardiogram (ECG): ECGs are a diagnostic method to determine the heart’s rhythm. It is a painless procedure and should be done within 10 minutes of being admitted to the hospital. During an ECG, electric sensors are attached to the skin to determine the electric impulses produced by every heartbeat. The signals are traced onto a paper and the pattern detected can be interpreted by the doctor to determine the type of heart attack. ECGs also determine the size of the heart, its contractions and relaxations, and if the valves work efficiently.
- Blood Tests: Damage to the muscles of the heart causes the broken-down protein to release into the blood. These protein concentrations can be measured by blood tests and are cardiac markers which are often elevated during heart attacks. One such protein is troponin.13
- Coronary Angiography: This diagnostic method is usually conducted after a heart attack to observe the exact position of the blockage. The test is carried out under local anaesthetic. A catheter is inserted into a blood vessel from the groin or arm and guided to the coronary arteries by x-ray imaging. A contrasting dye is pumped in through the catheter, and its movement through the vessels of the heart can help locate the site of a blockage. 12
- Other Tests: Chest X-Ray (to look for fluid in the lungs if a heart attack is not suspected), echocardiograms (a type of ultrasound to assess the efficiency of the heart’s chambers and valves in pumping blood) and cardiac CT/MRI scans (to diagnose heart problems and the extent of damage caused by heart attacks).
The type of treatments administered to the patient depends on the type of heart attack they have suffered from. However, all the treatments are aimed at restoring blood flow to the heart; they are:
- Coronary Angioplasty: A procedure that holds open the blocked artery by inserting a cylindrical mesh called a stent. The stent is expanded into place by an inflating balloon inserted via a catheter through a blood vessel in the groin or arm (similar to the process used in a coronary angiograph).14
- Thrombolysis Drugs: Certain drugs can prevent blood clots (e.g. antiplatelets and anticoagulants) by thinning blood so that it can easily flow through the arteries. Other drugs can break down blood clots (e.g. thrombolytics or fibrinolytics) by destroying their protein structures. Furthermore, drugs such as Glycoprotein IIb/IIIa inhibitors prevent blood clots from getting bigger (and are especially useful if patients are at risk of a second heart attack).15
- Coronary Artery Bypass Surgery (CABS): This procedure is used in place of coronary angioplasty (because the artery’s anatomy doesn’t support stent insertion). In CABS, a graft blood vessel (taken from the chest, leg or arm) is attached to the blocked coronary artery of the heart. This graft subsequently diverts the blood from the blocked region to the rest of the heart, thereby improving circulation.
Recovery after a heart attack is often multifaceted and can take many months. Its main purpose is to rehabilitate the patient back to physical fitness and daily life. More importantly, it is essential to reduce the risk of a second heart attack. During this period, the patient will receive physical and emotional support from a plethora of health care professionals. The initial recovery period happens in the hospital for close observation of the patient (usually take up to 3-5 days). This is followed by hospital discharge, where the rest of the recovery is done at home (several months).
Life after a heart attack
The heart is a vital organ that is essential to sustaining life. Naturally, a heart attack can be a traumatising experience, and in most cases, it is natural for the patient to be anxious about their health and daily life. According to the American Heart Association, 1 in 4 heart attack and stroke survivors has another.16 Therefore, it is crucial to monitor your lifestyle and not rush your rehabilitation in order to have a speedy and successful recovery. Proper recovery reduces the risk of a second heart attack and is centred around:
- Attending regular follow-up appointments with your cardiologist.
- Taking your prescribed medication daily.
- Participating in cardiac rehabilitation.
- Getting physical and emotional support.
- Managing your risk factors.
What not to do after a heart attack?
Smoking causes nearly 20,000 deaths from cardiovascular diseases in the UK every year, and the risk of a heart attack is up to four times greater for smokers.17 Chemicals found in cigarette smoke can cause inflammation in the blood vessels of the heart. Furthermore, it makes the arterial walls sticky and prone to atheromas.18 Studies have shown that in just one year, the risk of coronary heart disease is half that of someone who continues to smoke.17 And after 15 years, the risk of coronary heart disease and death is approximately the same as for someone who has never smoked.17 For heart attack patients, it is crucial to completely give up smoking.
A healthy diet delays the progressive nature of coronary heart diseases, particularly managing obesity, hypertension and diabetes, all of which are associated with risk factors for heart attacks. There are certain foods that can be avoided:
- Decrease Levels Of Unhealthy Fats: Fats are important to regulate body temperature, energy levels, vitamin absorption and hormone production. However, trans and saturated fats are types of ‘bad' cholesterol that increase the risk of atheroma deposits. For healthier alternatives, replace these fats with mono and polyunsaturated fats, also known as unsaturated fats or ‘good’ cholesterol. It is important to bear in mind that unsaturated fats still increase calorie intake, and should be regulated. Examples of fatty foods are listed below (adapted from British Heart Foundation):19
Limit the intake of this fat:
Fried foods and takeaways. Confectionaries like biscuits, cakes, pastries and pies. Hard kinds of margarine are made with hydrogenated oils.
Reduce the intake of this fat:
Processed and fatty meats like sausages, ham, burgers, bacon and cured meats. Hard cheeses like cheddar. Whole milk and ice cream. Butter, lard, ghee, suet, palm oil and coconut oil.
Consume these fats:
Peanut butter, almonds, cashews, hazelnuts, peanuts and pistachios. Rapeseed oil, olive oil, olives and avocados.
Consume these fats:
Oily fish like kippers, mackerel and salmon. Sunflower and corn oil. Nuts like walnuts, pine nuts, sesame seeds and sunflower seeds.
- Decrease Salt Levels: Salt levels play an important role in water regulation. The more salt we eat, the more water is retained in the blood, thereby increasing blood pressure. Some foods may label salt as sodium instead. For heart attack patients, it is recommended that salt levels are kept at 6g and sodium levels at 2g per day (one level teaspoon).20 Examples of salty foods are listed below (adapted from British Heart Foundation):21
High Salt & Sodium Foods
Limit the intake of these foods:
Cheese. Breakfast cereals. Canned soups. Bread, pastries and pizzas. Biscuits, cookies and cakes. Processed meats like sausages, bacon and ham. Sauces such as gravy, ketchup, mustard, brown sauce and soy sauce.
Low Salt & Sodium Foods
Increase intake of foods like:
Snacks: Sliced apple, celery sticks, rice cakes, unsalted nuts. Breakfast: Fresh fruit, yoghurt, cooked eggs, porridge oats. Lunch: Swap processed sandwich fillers for chicken, tuna, lettuce or tomato instead. Home-made Food: Soups, pasta sauces, and pizzas.
Healthier Salts & Seasonings
Pink or black or rock or crystal salts and salt flakes.
Alternate food seasonings to salt:
Chili, lemon juice, black pepper, fresh or dried herbs and spices.
- Decrease Sugar Levels: Studies have shown that there is an association between a high-sugar diet and a greater risk of dying from heart disease.22 Increased levels of sugar can increase inflammation and atheroma development. It is recommended that adults should have no more than 30g of sugar a day (approximately two tablespoons or lower).23
Excessive alcohol consumption causes abnormal heart rhythms and increases blood pressure, inflammation and build-up of atheroma in the arteries.24 Moreover, it disrupts healthy diet regimes because it increases calorie intake and lowers self-consciousness, making individuals more prone to eating unhealthy foods. Adults are recommended to not drink more than 14 units of alcohol per week, and there should be several alcohol-free days each week.25 For reference: a single shot (25 mL) of spirits, a glass (50 mL) of liqueur/sherry/fortified wine, and half a pint (300mL) of beer/ciders are all equivalent to 1 unit of alcohol.23 A standard glass of wine (175 mL) is 2.3 units of alcohol.25
Exercise (Mention that more strenuous activities may not be suitable)
After having a heart attack, high-intensity exercises should be avoided. For the first few days, it is essential to rest and do light activities. Exercise intensity can be gradually increased from light (sitting or walking up and down the stairs) to intermediate (taking a short walk) to high (aerobic exercise: jogging, running, cycling or swimming) to strengthen the heart. Exercise plans are fairly subjective to the doctor’s recommendation and the individual. It can happen over months and is further detailed in the cardiac rehabilitation plan.
Ignore psychological stressors
After a heart attack, worrying about your health and external factors related to personal life (such as finances, work and relationships) is imminent. However, emotional support and well-being are crucial to recovery. There is support available to patients. Symptoms of depression can persist due to anxiety; therefore, it is important to seek help. Mental health recovery is a slow process, but recovery happens one step at a time!
Returning to work can be a daunting task! After having a heart attack, the ability to return to work is dependent on your health and the type of job you have. If you have a desk job with light duties, you may be able to return to work within two weeks.26 However, if your job involves manual labour and your heart has suffered extensive trauma, it may take several months. Your healthcare professionals will guide you with the best course of action to return to a healthy and happy life.
If you drive, you can return to driving within one week of having a heart attack. In more complicated cases, driving should be withheld for up to four weeks.26 It is also important to remember that you may have other side effects of the heart attack that could stop you from driving. Your healthcare professionals will advise you on your abilities. You may be required to inform the relevant authorities about your condition.
If you are in a relationship, you will be able to return to sexual activities four to six weeks after having a heart attack.26 If you have had surgery, it may be longer. Sex will not increase your risk of another heart attack as much as any other activity would! Heart attacks can cause a loss of libido. For men, erectile dysfunction can happen due to emotional stress and side effects of heart medication. For women, vaginal dryness and difficulties reaching orgasm are common. If you are having sexual difficulties, do not be worried about discussing these issues with your doctor.
What to do after a heart attack?
Heart attacks are a stressful period, and food can be a coping mechanism for stress. Fueling your body with the right type of nutrition not only benefits you physically but mentally as well. The best way to achieve this is through a balanced diet. A balanced diet should consist of plenty of fruits and vegetables (remember, five a day keeps the doctor away!), plenty of starchy foods, some dairy products and sources of protein. Restrict yourself from fatty, salty or sugary foods.
After a heart attack, taking daily medication becomes a normal part of your life. It is necessary to take your medication regularly (even if you are well enough) as it lowers the risk of a second heart attack, reduces the blockage of arteries, manages angina and strengthens your heart. Some of these medications include:
- Antiplatelets: Drug that prevents blood clots, e.g. clopidogrel, prasugrel or ticagrelor.
- ACE (angiotensin-converting enzyme) inhibitors: Drugs that lower blood pressure by blocking hormones that regulate them.
- ARBs (angiotensin receptor blockers): Drugs that lower blood pressure, an alternative for patients who cannot take ACE, e.g. ramipril or losartan.
- Beta Blockers: Drugs that relax the heart muscles so that the heart rate is slower, blood pressure drops and less strain is put on the heart, e.g. bisoprolol.
- Statins: Drugs used to reduce cholesterol, e.g. atorvastatin.
- Glyceryl Trinitrate (GTN) Spray: Drug that treats angina.
Cardiac rehabilitation will be a critical part of your recovery programme where you will be liaising with nurses, physiotherapists, dieticians and exercise specialists. They will assist you in getting back to normal life by:
- Frequently monitoring and assessing your health
- Briefing you on the type of treatment and medication you will receive
- Advising you on risk factors that have contributed to your heart attack
- Advising you on the lifestyle changes that you need to make in order to manage those risks
- Advising and managing your diet, exercise and mental well-being plans
- Answering any questions that you have about financial support, welfare rights, housing and social care
Over the years, heart attacks have become less deadly due to the cutting-edge research conducted by our scientists and the excellent care provided by our healthcare professionals. We have a better understanding of how heart attacks work and ways of treating them. Studies have shown that the survival rates for people hospitalised for heart attacks are approximately 90% to 97%.27,28 More importantly, the good news is that the majority of the risk factors contributing to heart attacks can be managed by the patient themselves. To help prevent future heart attacks, the best treatment is to tackle the root of the problem, which is to take care of yourself: have a healthy diet, exercise daily, avoid drinking and smoking and look after your well-being.
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- Shih, Pei-an Betty, and Daniel T. O’Connor. ‘Hereditary Determinants of Human Hypertension: Strategies in the Setting of Genetic Complexity’. Hypertension, vol. 51, no. 6, June 2008, pp. 1456–64. DOI.org (Crossref), https://doi.org/10.1161/HYPERTENSIONAHA.107.090480.
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- Burnett, John R., and Amanda J. Hooper. ‘Common and Rare Gene Variants Affecting Plasma LDL Cholesterol’. The Clinical Biochemist. Reviews, vol. 29, no. 1, Feb. 2008, pp. 11–26.
- Schnell, Oliver, et al. ‘Type 1 Diabetes and Cardiovascular Disease’. Cardiovascular Diabetology, vol. 12, no. 1, 2013, p. 156. DOI.org (Crossref), https://doi.org/10.1186/1475-2840-12-156.
- Rosano, G. M. C., et al. ‘Menopause and Cardiovascular Disease: The Evidence’. Climacteric, vol. 10, no. sup1, Jan. 2007, pp. 19–24. Taylor and Francis+NEJM, https://doi.org/10.1080/13697130601114917.
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