Understanding Chest Pain
Chest Pain is a broad and purposefully vague term; where do we consider the chest? Solely the front of the body? Under the arms? Between the shoulder blades?
Pain from the chest can present anywhere in the upper torso and, furthermore, can radiate (spread) or refer (be felt elsewhere) in different places.
And how does the casualty describe the pain? A vice-like crushing pain? A dull, nagging ache or a sharp, focused stabbing pain? Is it constant or does it come and go? Is it continual or is it brought on by exercise or some other stimulus?
As well as the wide range of signs or symptoms which may present, Chest Pain may indicate as a variety of conditions, from trivial to life-threatening:
- Angina Pectoris
- Myocardial infarction ("heart attack")
- Dissecting aortic aneurysm
- Heart failure
- Pericarditis and cardiac tamponade
- Arrhythmia - atrial fibrillation and a number of other arrhythmias can cause chest pain.
- Pulmonary embolism
- Pneumothorax and Tension pneumothorax
- Pleurisy - an inflammation of the pleura (lining of the chest cavity) which can cause painful respiration
- Hiatus hernia - a protrusion of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm.
- Neuromuscular disorders of the oesophagus
- Chest wall injury
- Nerve damage
- Precordial catch syndrome - another benign and harmless form of a sharp, localised chest pain often mistaken for heart disease
- Breast conditions
- Panic attack
- Clinical depression
While the list of possible conditions may be intimidating and diagnosis outside of a hospital my be difficult we shall see that there are common themes of treatment for all.
Myocardial Infarction (MI)
A colloquialism for a Myocardial Infarction
Myo = muscle, Cardio = heart, Infarct = cell death through lack of oxygen. An MI is the death of muscle tissue of the heart; this may cause a Cardiac Arrest or an arrythmia.
The stopping of the heart's normal rhythm.
Abnormal electrical activity in the heart producing an abnormal 'heart beat'.
A build up of plaque, consisting largely of fats and white blood cells on the inside of the blood vessels.
A build up of calcium deposits resulting in hardening or a reduced elasticity of the blood vessel.
Restriction in blood supply.
A blockage of a vessel due to the lodging of a clot or other material which has become detached, traveled in the blood stream and caused an occlusion elsewhere.
A blockage at the site of origin of the clot.
High blood pressure - continual strain on the vessels walls can lead to weakness and widening of the vessel. This aneurysmis susceptible to rupture.
The Spectrum of Cardiac Conditions
Many cardiac conditions are functions of lifestyle; long term health problems which lead to atherosclerotic or arteriosclerotic problems or high blood pressure (hypertension). The most significant factors include:
- Poor diet
- Lack of exercise / sedentary work or lifestyle
- High stress
- Being male
- Family history
- Diabetes or other causative medical conditions
With this in mind, knowing your casualty will already help you form an opinion of what the cause of their chest pain might be; fit young, healthy people tend not to have cardiac disease!
The spectrum of cardiac conditions which are commonly found include both acute (severe and sudden onset) and chronic (long term development) medical conditions. This article looks at:
- Heart Attack
- Heart Failure
- Aortic Aneurysm
Chest pain does not always mean a person is having a heart attack (myocardial infarction or "MI"). Angina is a chronic condition and typically a symptom of atherosclerotic coronary disease1. Narrowing of the coronary arteries reduce the amount of oxygen the heart receives. In normal situations or at rest the patient feels no discomfort as the heart is receiving enough oxygen to meet it's normal demand.
During periods of exercise or stress, when the heart is working harder, the oxygen demand increases but is not able to to be met. It is during these moments that patients will exhibit chest pain including:
- Central chest pain
- May radiate across the chest or into the jaw, left arm or throat
- The pain usually lasts from 3 to 8 minutes but rarely above 15 minutes1.
- Pain is usually eased with rest (as the hearts oxygen demand reduces) or administration of the patient's Glyceryl Trinitrate medicine.
Angina Treatment (2,3)
- 2 puffs of GTN spray under the tongue – pain should ease within 5 minutes.
- If there is no improvement after 5 minutes, the casualty should administer a further 2 puffs.
- If there is no improvement after a further 5 minutes, the casualty should administer a third does of 2 puffs.
- If there is no improvement after a further 5 minutes (15 minutes in total since first administration) assume Heart Attack.
- Call 999 and encourage the casualty to chew 300mg aspirin.
Resting the patient and positioning them seated, or sat on the floor against a wall, together with prompt medication usually eases the condition. This is Stable Angina.
Unstable Angina is characterised by the signs and symptoms above but is triggered by progressively less exercise or fewer stimuli. If untreated, Unstable Angina can lead to an MI.
If in doubt - ASSUME IT IS A HEART ATTACK
Where angina is caused by a restriction of the cardiac vessels, a heart attack (MI) is usually caused by a complete or partial blockage; typically a piece of atherosclerotic plaque that has detached from the vessel wall during a moment of stress or exercise and become lodged within a cardiac artery. Alternatively, the build up of plaque can be so great the long term ischemia causes irreparable damage to the affected part of the heart.
In either situation, the lack of oxygen causes death of the muscle tissue which interrupts the normal electrical activity of the heart, resulting in Cardiac Arrest.
Cardiac Arrest is a medical emergency where death is imminent if decisive action is not taken quickly. Time is the most critical factor in a successful resuscitation. The casualty needs rapid defibrillation with CPR provided in the mean time to maintain oxygen supply to the brain. If defibrillation is not available, death is inevitable.
When unexpected Cardiac Arrest leads to to death, this is called Sudden Cardiac Death.
Signs & Symptoms
The conscious casualty may present a number of symptoms; the onset of symptoms is usually gradual, over several minutes, and rarely instantaneous.
- Chest pain is the most common symptom of acute MI and is often described as a sensation of tightness, pressure, or squeezing.
- Pain radiates most often to the left arm, but may also radiate to the lower jaw, neck, right arm, back, or epigastrium,where it may mimic heartburn.
- Other symptoms include excessive sweating (diaphoresis) weakness, light-headedness, nausea, vomiting and palpitations. These symptoms are likely to be induced by a massive surge of catecholamines from the sympathetic nervous systemwhich occurs in response to pain and the haemodynamic abnormalities that result from cardiac dysfunction.
- Due to a lack of oxygen reaching the brain (inadequate cerebral perfusion) unconsciousness follows.
- The conscious casualty should be sat down against something they can rest on; traditionally anyone exhibiting breathing problems or chest pain will not want to lie down.
- Bringing their knees up is said to reduce strain on the heart and increase perfusion to a marginal degree.
- If Oxygen is available it should be administered now.
- If the casualty has their own medication, they should be assisted to administer it.
- If they do not have their medication they should chew a 300mg aspirin or place a soluble aspirin on the tongue - they should not swallow the aspirin.
- Encouraging the casualty to chew - or allow the soluble aspirin to dissolve in the mouth - will allow the aspirin to be absorbed through the mucous membrane of the cheeks, allowing the drug to enter the blood stream much quicker than if it were swallowed.
- If a defibrillator is available, rapid defibrillation takes priority over attempted CPR. The defibrillator pads should be applied to the casualty as soon as possible and the defibrillator activated, even if the casualty is conscious and breathing; the defibrillator will be able to monitor the heart rhythm. There is no danger in applying a defibrillator to a conscious person prior to cardiac arrest.
- If the casualty becomes unconscious, and/or if there is any doubt that their breathing is not normal the casualty should be resuscitated in line with current, national protocols. (4)
- If the airway is compromised or ventilations are difficult, chest compressions take priority.
Remember: Defibrillation takes priority over CPR if both are available
Chest compressions take priority over ventilations if necessary
Heart failure is a typically chronic condition characterised by reduced cardiac output - the rate and volume of blood circulated by the heart. This can be caused by any of the heart diseases mentioned above but also by:
- Other heart diseases such as myocarditis ( myo= muscle, card= cardiac, itis= inflamation)
- Heart valve abnormalities such as leaking or reverse flow back into the chambers
- Arrhythmias; ineffective heart rhythms
- Cardiac tamponade - a build up of fluid in the sac surrounding the heart, inhibiting effective contraction and relaxation of the heart muscle preventing the ventricles from filling fully with blood.
When the pumping function of the left ventricle (which supplies the aorta with oxygenated blood to the rest of the body) cannot keep up with the input from the left atrium (bringing freshly oxygenated blood from the lungs via the pulmonary veins) the heart attempts two compensate by two possible mechanisms:
- Increase in heart rate
- Increase in size of the left ventricle
These compensatory mechanisms are not sustainable in the long term. Heart failure may occur in the left ventricle independently or in both ventricles. Left ventricular failure, unable to keep up with the input from the pulmonary veins, forces blood to back up into the alveoli of the lungs causing pulmonary oedmea - fluid leaking into the lungs. Failure of both ventricles can impair blood flow leading to reduced systemic perfusion which may manifest as weakness, confusion, drowsiness and low blood pressure (5).
Signs and Symptoms
- Shortness of breath - typically occurring when lying and eased by sitting upright.
- Sometimes with a dry cough.
- Fine crackles or wheezing on inhalation
- Frothy, pink sputum
- Distended jugular veins as a result of increased venous pressure
- Swollen ankles may indicate right sided heart failure
- Pale or cyanosed skin
- Agitation or restlessness
- Fast heart rate and breathing, high blood pressure
- Encourage the casualty to sit upright
- Assess the patient for signs and symptoms listed above
- Be reassuring; stress and anxiety of breathing problems cause a viscious feedback loop
- Gather a history of the patient - known medical conditions, medications...
- Encourage the patient to administer their medication
- Contact the emergency services
An aortic aneurism is a weakening and subsequent widening of the aorta - the main artery which leaves the heart to transport oxygenated blood to the body - typically caused by uncontrolled high blood pressure. A dissecting aneurism occurs when the inner layers of the aorta become separated allowing blood, under high pressure, to leak in between the layers further increasing the risk of rupture. A ruptured aorta will lead to almost instant death due to the vast amounts of uncontrolled internal bleeding.
An aortic aneurism may be very difficult to identify in a pre-hospital setting without equipment and the signs and symptoms may not initially be easy to differentiate from an MI but there are a number of 'classic' characteristics which may be present:
- The pain from an MI is often preceded by other symptoms (see above), becoming more severe with time and often described as a 'crushing pressure' rather than a 'stabbing' pain.
- The sharp, stabbing pain of an aortic aneurism is usually abrupt and without additional symptoms and does not abate, nor is it relived with rest.
- Pain is typically felt in the back, between the shoulder blades. This can occur in an MI but much more rarely.
- If you have equipment available there may be a difference in blood pressure on each arm or it may be difficult to detect a pulse in the lower limbs compared with the arms.
Arrange transport to hospital immediately.
Chest Pain can mean different things to different people so to attempt to identify the causes we need to know what to look for as the conditions sometimes present recognisable features:
Quality of pain
Severity of pain
Region / Radiation
Shortness of breath
Stress / Exercise
Tight, crushing pressure
Eases with rest
Shortness of breath
Pallor / Cyanosis
Stress / Exercise
Tight, crushing pressure
Increases with time
Shortness of breath
Frothy, pink sputum
Distended jugular veins
Wheezing or Crackles
Agitation / restlessness
Eases with positioning
Sharp / stabbing
Does not abate
Between shoulder blades
Different BP on each arm
Diminished pulse in lower limbs
What is consistent is the First Aid treatment for all Chest Pains;
- Rest, reassurance and positioning
- Rapid contact with the emergency services
- Access to a defibrillator as soon as practicable
- If you have Oxygen available and are able to administer it, it should be given at high flow at the earliest opportunity.
If the treatment is universal, why do we need to recognise different conditions?
In a pre-hospital environment everyone's abilities are limited by a lack of diagnostic tools and advanced treatment equipment, even for experienced clinicians. Delivering universal Basic Life Support is one aspect of First Aid; another aspect is contact with the emergency services and handing over information.
If you are able to suggest, in your opinion, what the underlying condition may be, this may help medical professionals prepare for the patient's Advanced Life Support, which does vary depending on the condition.
What if I get it wrong?
By providing a thorough history (signs and symptoms) medical professionals are also able to interpret your findings. They may agree or disagree but you have given the patient the best chance of the best treatment by provided detailed information. And you have provided life-saving treatment.
What if I get it completely wrong, and it was just indigestion!
You may not have correctly diagnosed the problem but the consequences of under-estimating the severity of Chest Pain are far greater than the consequences over-estimating the severity.
- Pollack, A.N. ed. (2001) Emergency Care and Transport of the Sick and Injured, Masachusetts, Ch14, p.532, Jones and Bartlett.
- British Cardiac Patients Association (2007) Heart Drugs. P1. http://www.bcpa.co.uk/pdf/HeartDrugs.pdf
- “Using your GTN spray to treat your chest pain” Guy’s And St Thomas NHS Foundation Trust. January 2013. http://www.guysandstthomas.nhs.uk/resources/patient-information/cardiovascular/using-your-GTN-spray-to-treat-your-chest-pain-discomfort.pdf
- Manual of Core Material (2006) Royal College of Surgeons of Edinburgh Faculty of Pre-Hospital Care, Edinburgh