Differentiating between cardiac chest pain and noncardiac chest pain can be a difficult task and one that paramedics must make on a daily basis. How can a paramedic differentiate between cardiac chest pain and noncardiac chest pain? The truth is a paramedic in the field can’t with complete accuracy. But there are a number of diagnostic clues while assessing the patient and key triggers that should be identified when you take a person’s history, which help make an educated guess about the aetiology of the chest pain.
If in doubt, it is generally best to treat any form of chest pain as cardiac in origin until proven otherwise. However, there are some exceptions to this, where the treatment regime for cardiac chest pain may be detrimental to the patient. A good clinician should be aware of these dangerous noncardiac causes of chest pain.
The following are all examples of dangerous noncardiac causes of chest pain: oesophageal varices, abdominal aortic aneurism, and a tension pneumothorax.
Key history clues in order to differentiate between cardiac and noncardiac chest pain:
How long has the patient had this pain for? Did the pain come on suddenly as the result of an injury, such as a fall or hit or did the pain start for no apparent reason? Always beware of the patient who was woken from their sleep in the because of a new onset of chest pain. Does the person have any cardiac risk factors or familial history of heart attacks? Age alone is a poor determinant for differentiating between cardiac and noncardiac chest pain. I recently attended a fit healthy 21 year old who had a STEMI and required angioplasty.
Key assessment clues when differentiating between cardiac and noncardiac chest pain:
Look at the patient. Most patients who are actually having a heart attack will look sick. Their skin will be cool, pale and diaphoretic. Can the patient take a deep breath – if the person complains of a sharp stabbing pain on inspiration/expiration it is likely to be related to pleurisy rather than problems with the heart. But there is nothing to say that a person with a chest infection who develops pleurisy doesn’t also have an underlying heart condition. Ask the patient to take one finger and point to the pain. Due to the way the phrenic nerves surround the heart and then outwards towards each arm, nociception in heart is difficult to pin-point. A patient who can point immediately to where the pain is, is unlikely to be having a heart attack. Whereas the patient who points to an entire area of the chest is more likely to be caused by heart problems. Assess the lungs. Congestion maybe related to a chest infection and increases the likelihood that the pain is related to pleurisy. Alternatively, crackles (generally indicating fluid in the lungs) is related to poor cardiac output and heart failure.
In hospital and in some ambulance services repeated 12 ECGs and serial blood test are taken to definitely identify if the cause of the chest pain has been related to damage to the heart or not. While 12 lead ECG interpretation is become commonplace in most Ambulance Services the acceptance of blood pathology for cardiac enzymes is relatively new and expensive, but look to be on their way.
Common heart attack imitators:
Pleurisy, chest infections, asthma, GORD, oesophageal varicies, aortic aneurism/abdominal aortic aneurism, traumatic injuries, fractured ribs, pulmonary embolism, subcutaneous emphysema, pericarditis, and most common in younger men, costochondritis.
Assessing chest pain is a paramedic’s bread and butter case, so it pays to have a thorough understanding of the pathophysiology of chest pain and well adept at assessing it. In general, if in doubt, treat the patient for cardiac chest pain.