Acute Coronary Syndromes

 

The term 'acute coronary syndromes' encompasses a range of conditions from unstable angina to ST-segment-elevation myocardial infarction (STEMI), arising from thrombus formation on an atheromatous plaque.  If untreated, the prognosis is poor and mortality high, particularly in people who have had myocardial damage. Appropriate triage, risk assessment and timely use of acute pharmacological or invasive interventions are critical for the prevention of future adverse cardiovascular events (myocardial infarction, stroke, repeat revascularisation or death)

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Myocardial infarction (STEMI)

ST-segment-elevation myocardial infarction (STEMI) occurs when a coronary artery becomes blocked by a blood clot, causing the heart muscle supplied by the artery to die

Signs and symptoms

While the classic symptoms of a myocardial infarction (heart attack) are chest pain and shortness of breath, the symptoms can be quite varied

The most common symptoms of a heart attack include:

  • pressure or tightness in the chest
  • pain in the chest, back, jaw, and other areas of the upper body that lasts more than a few minutes or that goes away and comes back
  • shortness of breath
  • sweating
  • nausea
  • vomiting
  • anxiety
  • a cough
  • dizziness
  • a fast heart rate

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NOTE:  Not all people who have heart attacks experience the same symptoms or the same severity of symptoms. Chest pain is the most commonly reported symptom among both women and men

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However, women are more likely than men to have:

  • shortness of breath
  • jaw pain
  • upper back pain
  • lightheadedness
  • nausea
  • vomiting

In fact, some women who have had a heart attack report that their symptoms felt like the symptoms of the flu

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Causes

There are several factors that can lead to a blockage to one of the coronary arteries, which include the following:

  • Bad cholesterol
    • Bad cholesterol, also called low-density lipoprotein (LDL), is one of the leading causes of a blockage in the arteries. LDL cholesterol can stick to the walls of your arteries and produce plaque. Plaque is a hard substance that blocks blood flow in the arteries. Blood platelets, which help the blood to clot, may stick to the plaque and build up over time
  • Saturated fats
    • Saturated fats may also contribute to the buildup of plaque in the coronary arteries. Saturated fats are found mostly in meat and dairy products, including beef, butter, and cheese. These fats may lead to an arterial blockage by increasing the amount of bad cholesterol in your blood system and reducing the amount of good cholesterol
  • Trans fat
    • Another type of fat that contributes to clogged arteries is trans fat, or hydrogenated fat. Trans fat is usually artificially produced and can be found in a variety of processed foods. Trans fat is typically listed on food labels as hydrogenated oil or partially hydrogenated oil

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Risk factors

Certain factors can increase a person's chances of a heart attack, including:

  • high blood pressure
  • high cholesterol levels
  • high triglyceride levels
  • diabetes and high blood sugar levels
  • age (higher risk for men > 45 years, and women > 55 years)
  • family history of early heart disease
  • stress
  • lack of physical activity
  • use of certain illegal drugs, including cocaine and amphetamines
  • a history of preeclampsia, or high blood pressure during pregnancy

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Diagnosis

To determine whether someone has had a heart attack, listen to their heart to check for irregularities in their heartbeat, and measure the patient's blood pressure.  An electrocardiogram (EKG) may be done. Blood tests can also be used to check for proteins that are associated with heart damage, such as troponin

Other diagnostic tests include:

  • a stress test to see how the heart responds to certain situations, such as exercise
  • an angiogram with coronary catheterization to look for areas of blockage in the arteries
  • an echocardiogram to help identify areas of the heart that aren’t working properly

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If you suspect that a patient has suffered an MI refer urgently to secondary care

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Unstable angina and NSTEMI

Unstable angina is chest pain that occurs at rest or with exertion or stress. The pain worsens in frequency and severity. Unstable angina means that blockages in the arteries supplying your heart with blood and oxygen have reached a critical level

An attack of unstable angina is an emergency and you should seek immediate medical treatment. If left untreated, unstable angina can lead to heart attackheart failure, or arrhythmias (irregular heart rhythms). These can be life-threatening conditions

Causes

The principal cause of unstable angina is coronary heart disease caused by a build-up of plaque along the walls of your arteries. The plaque causes your arteries to narrow and become rigid. This reduces the blood flow to your heart muscle. When the heart muscle doesn’t have enough blood and oxygen, it causes feel chest pain

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Risk factors

Risk factors for coronary heart disease include:

  • diabetes
  • obesity
  • a family history of heart disease
  • high blood pressure
  • high low-density lipoprotein (LDL) cholesterol
  • low high-density lipoprotein (HDL) cholesterol
  • being male
  • using any form of tobacco
  • leading a sedentary lifestyle

NOTE:  Men 45 years and older and women 55 years and older are more likely to experience unstable angina

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Signs and symptoms

The main symptom of angina is chest discomfort or pain. The sensation can vary depending on the person

Angina symptoms include:

  • chest pain that feels crushing, pressure-like, squeezing, or sharp
  • pain that radiates to your upper extremities (usually on the left side) or back
  • nausea
  • anxiety
  • sweating
  • shortness of breath
  • dizziness
  • unexplained fatigue

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NOTE:  It is possible for stable angina to progress to unstable angina. Patients with stable angina should be aware of any chest pains they feel even when at rest, and watch for chest pains that last longer than they typically do. If a patient takes nitroglycerin for relief during a stable angina attack, they may find the medicine does not work during an unstable angina attack

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Diagnosis

Perform a physical examination of the patient, including checking their blood pressure

Other tests that may be used to confirm unstable angina are:

  • blood tests, to check for creatine kinase and cardiac biomarkers (troponin) that leak from the heart muscle if it’s been damaged
  • electrocardiogram, to see patterns  that may indicate reduced blood flow
  • echocardiography, to look for evidence of blood flow problems
  • stress tests, which can  make angina easier to detect
  • computed tomography angiography
  • coronary angiography and heart catheterization, to study the health and caliber of the arteries

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How NSTEMI differs

Unstable angina (UA) and non-ST elevation (non-Q wave) myocardial infarction (NSTEMI) differ primarily in whether the ischemia is severe enough to cause sufficient myocardial damage to release detectable quantities of a marker of myocardial injury. Unstable angina is considered to be present in patients with ischemic symptoms suggestive of an ACS and no elevation in troponin, with or without ECG changes indicative of ischemia (eg, ST segment depression or transient elevation or new T wave inversion). Since an elevation in troponin may not be detectable for up to 12 hours after presentation, UA and NSTEMI are frequently indistinguishable at initial evaluation. ST segment and/or T wave changes are often persistent in NSTEMI while, if they occur in UA, they are usually transient

It should be kept in mind that the sensitivity of the biomarker test (usually troponin) used to evaluate patients with ACS determines whether a patient is labeled as having UA or NSTEMI. With the development of increasingly more sensitive troponins, it can be anticipated that the percentage of patients with UA will decrease and the percentage with NSTEMI will increase

NOTE:  The causes, symptoms, risk factors and investigations for diagnosis are primarily the same as for unstable angina

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Acute chest pain

Initial assessment and referral

  1. Check immediately whether people currently have chest pain. If they are pain free, check when their last episode of pain was, particularly if they have had pain in the last 12 hours
  2. Determine whether the chest pain may be cardiac by considering:
    1. the history of the chest pain
    2. the presence of cardiovascular risk factors
    3. history of ischaemic heart disease and any previous treatment
    4. previous investigations for chest pain
  3.  Initially assess people for any of the following symptoms, which may indicate an ACS:
    1. pain in the chest and/or other areas (for example, the arms, back or jaw) lasting longer than 15 minutes
    2. chest pain associated with nausea and vomiting, marked sweating, breathlessness, or particularly a combination of these
    3. chest pain associated with haemodynamic instability
    4. new onset chest pain, or abrupt deterioration in previously stable angina, with recurrent chest pain occurring frequently and with little or no exertion, and with episodes often lasting longer than 15 minutes
  4.  Refer people to hospital as an emergency if an ACS is suspected and:
    1. they currently have chest pain or
    2. they are currently pain free, but had chest pain in the last 12 hours, and a resting 12-lead ECG is abnormal or not available
  5. If an ACS is suspected and there are no reasons for emergency referral, refer people for urgent same-day assessment if:
    1. they had chest pain in the last 12 hours, but are now pain free with a normal resting 12-lead ECG or
    2. the last episode of pain was 12–72 hours ago

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Initial management before hospital admission

  1. When an ACS is suspected, start management immediately by taking a resting 12 lead ECG.  Do not delay transfer to hospital. Send the ECG results to hospital before they arrive if possible
  2. Offer pain relief as soon as possible. This may be achieved with GTN (sublingual or buccal), but offer intravenous opioids such as morphine, particularly if an acute myocardial infarction (MI) is suspected
  3. Offer people a single loading dose of 300 mg aspirin as soon as possible unless there is clear evidence that they are allergic to it
  4. Do not routinely administer oxygen, but monitor oxygen saturation using pulse oximetry as soon as possible, ideally before hospital admission

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Electrocardiogram

An electrocardiogram (ECG) can usually be undertaken in primary care.  If your practice does not offer ECGs, please request an ECG from East Kent Hospitals

Blood tests / Phlebotomy

If your practice does not have a practice nurse who is trained to take bloods, you can refer a patient to the Pathology Department at East Kent Hospitals for a blood test (find details here)

Alternatively, Buckland Hospital (Dover) and the Royal Victoria Hospital (Folkestone) both operate a walk-in service where no appointment is necessary, except for if the patient requires a Glucose Tolerance Test (GTT).  In the event that a GTT is required, please call 01304 222552 (for Buckland) and 01303 854484 (for Royal Victoria) to arrange a suitable appointment

Please ensure that the patient remembers to take with them their blood test form to the walk-in centres

Advice and Guidance is being made available for all specialties, and is being provided by consultant specialists at East Kent Hospitals.  To make a request or to check to if a query has been answered, you will need to log in via the electronic Referral System (eRS)

Click here for the "how to access" e-Referral Advice and Guidance Manual for instructions on how to make a request and check responses

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