Emergency Medicine/Chest pain
Multiple conditions may present as chest pain. These can range from simple causes such as indigestion, to extremely severe conditions, such as Myocardial Infarctions (heart attack). Potentially life threatening causes of non-traumatic chest pain include heart attacks, pulmonary embolus (clot in the lung), tension pneumothorax and aortic dissection.
- The first step in the diagnosis of chest pain involves obtaining a history and performing a physical examination. This history and physical may provide important clues to the most likely diagnoses.
- The next step is to obtain an EKG (electrocardiogram).
This may show evidence of heart muscle (myocardial) injury or arrhythmias (irregular rhythm). The most important finding for heart muscle injury on the EKG is elevation or depression of the ST segment. Elevation of the ST segment with ongoing chest pain suggests acute myocardial infarction (ST elevation myocardial infarction or STEMI) and requires emergency therapy to open the culprit artery. Blood tests must be obtained to detect elevation of biochemical markers of heart damage('cardiac enzymes' like Troponin I or T, or CK-MB). Elevated troponin blood tests are more specific indicators of myocardial damage and suggest an increased risk of further cardiac events. It is important to note that no single test is capable of conclusively proving or disproving the diagnosis of myocadial infarction. A Chest X-ray may also be helpful. Newer diagnostic modalities in chest pain include using the new 64 slice CT (Computerized Tomography) Scanners, MRI (Magnetic resonance imaging), or Echocardiography. CT scans are being evaluated for a "triple rule out" strategy to image the coronary arteries (to assess for myocardial infarction), the aorta (for aortic dissection), and to rule out pulmonary embolism.
The treatment of chest pain varies widely, and is dependent on the cause.
- Myocardial infarction or ischemia is traditionally treated with oxygen, nitrates, morphine and aspirin (an anti-platelet medication). The definitive treatment of a partial or complete blockage of one or more of the coronary arteries angioplasty, stenting or cardiac bypass surgery.
- Heparin or Warfarin (also known as coumadin) are used prevent the blood from clotting. Blood clotting plays a significant role in the evolution of a "heart attack" or myocardial infarction, in the development of a clot in the deep venous blood vessels in the legs (ex. a deep venous thrombosis - "DVT"), and potentially with the development of emboli in the atrium of the heart in chronic arrythmias such as atrial fibrillation.
- "Decompression" is the only definitive treatment for a pneumothorax. This entails the insertion of a needle or chest tube between the ribs, into the pleural space that lines the lung and the chest wall. The needle or chest tube is connected with a one way valve designed to allow air to escape from the pleural space with positive pressure (ex. the patient takes a breath in), without allowing the air to re-enter when negative pressure exists (i.e. with expiration).
- Surgery or stenting are the only definitive treatments for aortic dissection.