Chest pain is a frequently encountered medical condition that paramedics attend to in the out-of-hospital environment (Pittet et al, 2014). It is both a common and threatening problem because in many instances the cause is can be serious, especially if the chest pain had a sudden onset (Bonaca and Sabatine, 2019: 2601).
Chest pain has been defined as pain in the thorax, and can be classified by: its cause, for example by being of cardiac or non-cardiac origin; and its type of pain, for example localised or poorly localised, or pleuritic versus non-pleuritic (National Institute for Health and Care Excellence, 2021).
As heart disease is the leading cause of death in Western nations, it is important that paramedics are able to identify and manage chest pain accurately and according to the risk to the patient (Institute for Health Metrics and Evaluation, 2018). In the paramedic context, identifying risk is an important part of determining the best pathway for patients with chest pain (Best, 2017).
This article covers the main causes of chest pain, the signs and symptoms, tools of diagnosis and assessment. It also considers beneficial patient management strategies that can be incorporated into the paramedics' practice. This article references links to the clinical examination series (Kirk, 2020).
Chest pain causes
There are various causes of chest pain, including those of cardiac, gastrointestinal and respiratory origin. Table 1 shows the common causes and describes their presentation.
| Origin | Examples | Clinical features | Electrocardiogram (ECG) features |
|---|---|---|---|
| Cardiac | Acute coronary syndromes (ACS) | Shortness of breath, diaphoresis, radiation of pain down shoulders and arms are common | ST elevation and depression, pathological Q waves (a later sign and may not occur), T wave abnormalities and bundle branch blocks |
| Angina | Often stated as similar to the above ACS, but often transient in nature | ST segment changes may occur in a few cases. Ischaemic changes may be noted, which can be transient | |
| Pericarditis | Constant sharp pain that can be exacerbated by movement or inspiration | Widespread (diffuse) ST-elevation, PR segment depression, J point notching |
|
| Aortic dissection | Severe and sudden (worst pain ever) in 90% of cases. Maximum pain on onset and does not build up in a crescendo as in myocardial infarction. |
Can occasionally mimic ST-elevation myocardial infarction with ST segment changes. Most commonly mimics inferior myocardial infarction but can mimic any type. Tachycardia is often present | |
| Gastrointestinal | Gastritis | Burning lower chest pain, exacerbated by lying down | Nil normally but tachycardia is often present |
| Pancreatitis | Epigastric/upper right quadrant/chest pain | Nil normally but tachycardia is often present | |
| Peptic ulcer disease | Dull epigastric pain, exacerbated by food consumption | Nil normally but tachycardia is often present | |
| Musculoskeletal | Costal cartilage inflammation | Pain on palpation, during movement and/or on inspiration | Nil normally but tachycardia is often present |
| Respiratory/lung | Pulmonary embolism | Non-specific ECG findings (usually sinus tachycardia), shortness of breath, may be accompanied by unilateral leg swelling and fever | Tachycardia is the most common ECG change. The S1Q3T3 sign can occur but not in every case of pericarditis |
| Spontaneous pneumothorax | Decreased breath sounds, hyperresonance when percussed | Nil normally but tachycardia is often present | |
| Pneumonia | Sharp, pleuritic pain, cough, sputum and fever. Decreased breath sounds or crackles on auscultation | Nil normally but tachycardia is often present | |
| Psychological | Panic disorder | Unexpected onset of multiple symptoms such as chest pain, palpitations, nausea, diaphoresis, fear of death and shortness of breath | Usually none but tachycardia is common |
Source: Tintinalli et al (2016)
Chest pain has many origins and there are many types of pain, which depend on what is triggering it. The distribution of the presentation of chest pain in an emergency department is shown in Figure 1.
Chest pain generally originates from one of the organs in the chest (heart, lung or oesophagus) or from the components of the chest wall (skin, muscle or bone).
Pericarditis is an inflammation of the two layers of the pericardium. Pain from acute pericarditis is described as sharp, severe and constant, with a substernal location that may radiate to the back, neck or shoulders. Pericarditis is thought to arise from a viral, fungal or bacterial infection (Mootham, 2020).
Occasionally, organs close to the chest, such as the gallbladder or stomach, may cause chest pain (Kumar and Clarke, 2017). Pain in the chest may also result from respiratory disease. This may be reported as pain that is localised and sharp, often termed pleuritic. Sometimes pain originating from the chest may be felt in an area of the body surface such as the skin that is remote from the site of injury. This is known as referred pain and occurs when multiple sensory neurons transmit visceral signals from an internal organ (such as the heart muscle) and a body surface area to converge on an ascending tract (Copstead and Banasik, 2013). When the brain is unable to distinguish visceral signals from the more common signals that arise from the body surface area, pain is felt in the body surface area instead of the internal organ.
A prime example of this phenomenon is when a patient feels pain with angina or a myocardial infarction (MI). In this case, the pain can be felt on the body surface areas of the neck (including the jaw), left shoulder or down the left arm. Common pathways for referred pain are shown in Figure 2.
Patient assessment
Every patient who is experiencing chest pain should have a thorough physical assessment to rule in or out serious or life-threatening problems that may need immediate interventions. The aetiology of chest pain will be explained below with reference to assessment techniques and equipment.
The paramedic should begin with a cardiovascular assessment. They also need to understand that chest pain may originate from abdominal pain, so both of these areas may need to be assessed. After cardiovascular assessment and potentially abdominal assessment have been carried out, a paramedic should follow several processes to help identify the problem.
The paramedic should begin with the patient interview to find out about any previous medical history such as coronary artery disease and risk factors including hypertension, smoking and hypercholesterolaemia. These may point to cardiac origins—it is important to identify these early. In such cases, the patient is in a higher risk category so the paramedic should be alerted to the potential for myocardial ischaemia being the cause of chest pain (Petersen et al, 2017).
Cardiac chest pain versus non-cardiac chest pain
Identifying cardiac-related chest pain is key to good care and maximising patient safety. A paramedic should always err on the side of caution when chest pain is a potentially of cardiac origin. A patient's signs or symptoms can help paramedics differentiate between cardiac and non-cardiac chest pain (Figure 3).
Describing chest pain
While interviewing the patient, a common mnemonic such as SOCRATES (Table 2) should be incorporated to assist the paramedic in an accurate description of the event and subsequent pain.
| Questions to ask the patient | |
|---|---|
| Site | ‘Can you point to the location of the pain?’ |
| Onset | ‘When did the pain start?’ |
| Character | ‘Could you use one word to describe what the pain feels like?’ |
| Radiates | ‘Does the pain radiate to any other part of your body?’ |
| Associated symptoms | ‘Do you have any other symptoms that come along with the pain? (Nausea, sweating, dizziness)’ |
| Time/duration | ‘When did the pain start? Has the pain changed since it first started (e.g. got better or worse) or does it feel the same?’ |
| Exacerbating/relieving factors | ‘Does anything make the pain better or worse?’ |
| Severity | ‘On a scale of 0–10, 0 being no pain and 10 being the worst pain you could imagine, what would you score your current pain?’ |
Source: adapted from Brown et al (2019: 13.)
While words can describe pain, hand gestures can be very revealing and allude to the underlying aetiology of the condition. Patients may provide diagnostic clues by the hand gestures they spontaneously make when describing their chest pain. Four of these gestures are: the Levine sign—placing a clenched fist against the sternum; the palm sign—placing the extended palm against the sternum; the arm sign—gripping the left arm; and the pointing sign—pointing to a single point on the chest with one or two fingers (Figure 4).
Gestures suggesting deep, poorly localised visceral pain (the Levine and palm signs) or pain radiating to the left arm (the arm sign) show coronary disease is more probable, whereas gestures indicating well-localised somatic pain (the pointing sign) mean ischaemic cardiac pain is less likely (Marcus et al, 2007: 85).
Using an electrocardiogram to assist diagnosis of chest pain of cardiac origin
An electrocardiogram (ECG) can reveal key information about a patient's condition and assist health professionals to rule in or out acute coronary syndromes (ACS) such as unstable angina and MI, both of which are life-threatening cardiac conditions (Phalen and Aehlert, 2018).
It can also provide evidence of past or previous heart damage and how their heart may have attempted to adapt to this change or has become damaged over time (Mann et al, 2010).
In addition, the ECG can assist paramedics in the diagnosis of other conditions that are not in the family of acute coronary conditions, such as unstable arrhythmias, pulmonary embolism, pericarditis, angina or some types of cardiomyopathy (Tomaselli and Zipes, 2019). All of these conditions can cause chest pain.
ECG changes can indicate signs of ischaemic problems in the heart when the blood supply is interrupted (Phalen and Aehlert, 2018). Myocardial ischaemia is a critical condition and the patient should be managed in an appropriate, timely fashion (Tomaselli and Zipes, 2019).
Health professionals must know what a normal ECG should look like. Figure 5 depicts an ECG trace showing a normal cardiac cycle. Providing a lesson in ECG reading is beyond the scope of this article, but using a systematic interpretation method such as the 5-step method by Aehlert (2018) can provide good basics that will be valuable for any paramedic's skill set.
A few considerations when reading an ECG are:
A baseline 12-lead ECG should be performed on every patient who is experiencing chest pain and subsequent serial ECGs should be performed at least every 15 minutes. This provides the means to watch for changes during patient care (Kumar and Clark, 2017: 2475).
If an MI is identified, the patient should be started on reperfusion therapy promptly or transported straight to a facility that is able to perform percutaneous coronary interventions (PCI) (Penumetsa et al, 2012; Benjamin et al, 2019).
A normal ECG does not exclude ischaemia or acute MI although it can prompt further investigation for non-coronary causes of chest pain (Golberger, 2018). Normal or near-normal ECGs have been seen in 5%–10% of patients with acute MI (Smith and Mahler, 2020). As an ECG shows a single time point during a potential pathologic process, ECGs should be repeated at short intervals.
Some patients who develop chest pain may not seek medical assistance until the later stages. Pathological Q waves (showing a myocardial infarct has occurred) may develop within 1–2 hours of the onset of symptoms of acute MI, although may often take 12 hours and occasionally up to 24 hours to appear (Morris and Brady, 2002).
Diagnosis tools new to paramedicine
Troponin and other assays
Historically, troponin assays had poor sensitivity so were not clinically accurate in determining the occurrence of cardiac ischaemia. However, newer tests with higher sensitivity have been developed and are now part of the diagnostic tools used to identify the occurrence of an MI (Doust and Glasziou, 2018).
Studies have concluded that implementing troponin testing within paramedicine could be valuable for patient care and outcomes, and is feasible in the out-of-hospital environment (Sørensen et al, 2011; Venturini et al, 2013; Ezekowitz et al, 2015). However, concerns have arisen over the potential for overdiagnosis because of the test's high sensitivity (Doust and Glasziou, 2018).
Nonetheless, this kind of highly sensitive test could assist paramedics to rule out ACS rather than purely to rule it in; paramedics should keep it in mind that other diagnostic tools and assessments should still be used.
So, does troponin testing have a role in the out-of-hospital environment or should it be delayed until the patient reaches hospital? The jury is still out (Mauro et al, 2017).
Clinical risk scores and decision aids
Clinical risk scores are often used to identify patients who may be at a high risk of developing conditions such as pulmonary embolism or MI, both of which are life threatening. Tools such as the TIMI Score (Antman et al, 2000) (Table 3), HEART score (Tintinalli, 2016: 331) (Table 4) and the Wells Criteria for Pulmonary Embolism (Wells et al, 2000; Fesmire et al, 2011) (Table 5) combine clinical information to risk stratify patients and guide key decisions. These tools can assist the paramedic to guide priorities such as treatment, management, patient referral and decision pathways. If a patient is suspected to be at a high risk of pulmonary embolism or MI, they should be transported immediately to an appropriate facility.
| TIMI score | Yes 1 point | No 0 points |
|---|---|---|
| Age ≥65 years | ||
| At least three risk factors for ACS | ||
| Aspirin use in the last 7 days | ||
| Prior coronary stenosis ≥50% | ||
| ≥2 angina episodes within the past 24 hours | ||
| ST changes of at least 0.5mm in contiguous leads | ||
| Elevated serum cardiac biomarkers | ||
| Total score | ||
| Low risk | ||
| Intermediate risk | ||
| High risk |
Source: Antman et al (2000). Each of these elements can be assigned with 0 or 1 points, resulting in a score of 0–7. The TIMI score predicts the risk of all-cause mortality, MI and severe recurrent ischaemia requiring urgent revascularisation within 14 days after admission as well as benefit of thrombolytics. High-risk (TIMI Risk Score >5 points) and moderate-risk (TIMI Risk Score 3–4 points) and low (TIMI Risk Score <3 points)
| HEART Score | Points | |
|---|---|---|
| History | Highly suspicious | |
| Moderately suspicious | ||
| Slightly suspicious | ||
| ECG | Significant ST-depression | |
| Nonspecific repolarisation abnormality | ||
| Normal | ||
| Age | ≥65 | |
| 45–65 | ||
| ≤45 | ||
| Risk factors | Three or more risk factors | |
| 1–2 risk factors | ||
| No risk factors | ||
| Troponin | ≥3x normal limit | |
| 1–3x normal limit | ||
| ≤ normal limit |
Source: Tintinalli (2016: 331). The HEART score is composed of five parameters of clinical judgement: History, ECG, Age, Risk factors and Troponin. By appreciating each of these five elements with 0, 1 or 2, each patient patients will receive a score of 0 - 10. The HEART score divides patients into low (0–3), intermediate (4–6) or high-risk groups (7–10), with mean risks of an event of 0.9%, 12% and 65%, respectively.
| Criteria | |
|---|---|
| Suspected DVT | 3 |
| An alternative diagnosis is less likely than PE | 3 |
| Heart rate <100 beats/minute | 1.5 |
| Immobilsation or surgery in the previous 4 weeks | 1.5 |
| Previous DVT/PE | 1.5 |
| Haemoptysis | 1 |
| Malignancy (on treatment, treated in the last 6 months or palliative) | 1 |
DVT: deep vein thrombosis; PE: pulmonary embolism
Sources: Wells et al (2000); Fesmire et al (2011)
Patient management
Fundamental to managing any medical condition is gaining an understanding of the aetiology of the disorder. As described above, many tools are available to assist paramedics in determining the cause of a problem. The next step is to understand and use patient management strategies for those who are experiencing chest pain.
Using a systematic process for patient management is key to ensuring the basic principles of providing good care in paramedicine are not overlooked.
Basic principles of care in chest pain
A paramedic can decide the key priorities through the following questions.
Answers to these questions will help guide decisions for care that may happen on scene as opposed to during conveyance. Any patient who is determined to be unstable or having a cardiac complaint requires urgent, time-critical treatment and transport. Patients who are not critically unwell and can be managed in alternative ways.
Take a systematic approach
Where appropriate, the chest should be examined and observed for any injuries or signs that may indicate a cause of the chest pain. Gently inspect, auscultate, percuss and palpate the chest and ask the patient to take a deep breath, noting any change to the chest pain discomfort.
Once a full set of vital signs and relevant physical assessments have been completed, the paramedic should move on to attempting to alleviate the symptoms and, in some cases, work actively to prevent future deterioration.
Treating and managing pain
The management of chest pain is guided by an understanding of the underlying condition. For example, if the problem has a musculoskeletal origin (typically somatic pain), then analgesics such as paracetamol and ibuprofen are appropriate; non-steroidal anti-inflammatory drugs, which include ibuprofen, provide not only pain relief but also anti-inflammatory actions. Pain originating from organs within the body (visceral pain) is often more widely distributed is more difficult to treat.
It is important to begin by establishing an accurate baseline score of the pain. The use of scales such as a 0–10 numerical scale is common throughout paramedicine and gives the paramedic a working benchmark for guiding pain control and relief medications. By asking the patient to rate their pain along the scale, it can be determined if the pain is considered mild, moderate or severe.
Alongside offering medications for pain control, the paramedic should also consider the use of non-pharmacological pain relief such as cool compresses, warmth, distraction and splinting. Additionally, there is evidence for the use of approaches such as acupressure and transcutaneous electrical impulses for musculoskeletal pain in particular (Pak et al, 2015).
The balanced approach to pain management is preferred in paramedicine. Here, the paramedic may administer medications with differing mechanisms of action at the same time for a synergistic effect. There is evidence to support this approach, with research showing that opiate doses can be reduced if given alongside other medications such as paracetamol or ibuprofen (Li, 2019). This has the additional benefits of fewer adverse effects than a larger dose of one drug alone (Li, 2019).
Mild pain
Most mild pain is treated with oral medications such as paracetamol, ibuprofen or oral morphine. These may be used together and in combination. Additionally, inhaled analgesia such as 50% nitrous oxide and 50% oxygen (Entonox) and methoxyflurane are useful if the respiratory system is not involved and the chest pain does not involve pain on inspiration.
Moderate-to-severe pain
Moderate-to-severe pain is often controlled by the use of opiates such as codeine, morphine and fentanyl; the efficacy of these is paramedicine is well established (Middleton et al, 2010). Additionally, intravenous paracetamol, benzodiazepines and ketamine may be used as an adjunct to provide synergistic effects.
Treating and managing chest pain in acute coronary syndrome
Managing chest pain for a patient who has myocardial ischaemia should be tailored to individual need based upon clinical presentation, perfusion status and the likelihood of an MI.
A patient who is experiencing chest pain during myocardial ischaemia may feel pain relief from the administration of glyceryl trinitrate (GTN). GTN provides pain relief primarily through its vasodilatory effects on blood vessels throughout the body, which reduce the amount of blood returning to the heart. GTN will produce some vasodilatory effects within the heart's arteries, but these effects are less important than the systemic reduction of returning blood. By reducing the returning blood volume, preload (the amount of blood within the ventricle at the end of diastole) is also reduced. This puts the heart under less pressure to expel blood and therefore reduces myocardial oxygen demand.
Care needs to be taken to not use GTN in patients who already have decreased blood returning to the heart; these patients are called ‘preload’ dependent. Patients at risk of being preload dependent are those experiencing hypovolaemia and cardiac conditions such as tachycardia, bradycardia, uncontrolled atrial fibrillation and, occasionally, right-sided MI.
Opioids have long been used in the control of cardiac chest pain. Evidence suggests that they may interfere with metabolism of antiplatelet drugs such as clopidogrel and ticagrelor (Hobl et al, 2014; Ibrahim et al, 2018; Lapostolle et al, 2019). The findings of opioid and antiplatelet interaction are significant, especially considering the importance of such a time-sensitive matter as prehospital thrombolysis.
Opioids may be highly effective for pain relief in ACS. However, further studies should be completed to ensure their use in paramedicine is based on evidence. Furthermore, as there is currently no superior alternative to opioids, further research for other pharmacological agents that may be used in patients with ACS is required.
Conclusion
Chest pain is commonly attended to by paramedics. This article provides advice to paramedics on the assessment, diagnosis and management of patients who are experiencing chest pain.
Using a systematic approach is highly recommended. This can be based upon the ABCD principles and followed using a tailored plan based upon patient presentation and aetiology of the condition. Pain relief should be provided with a balanced approach, using a multimodal method if possible to provide synergistic pain relief and minimise adverse effects.