Wilderness and Rescue Medicine 7th Edition Jeffrey Isaac, PA-C and David E. Johnson, MD

Chapter 27: Chest Pain

As with the abdomen, there are a number of pos- sible causes of chest pain including heart attack, muscle spasm, and respiratory problems. Again, the diagnosis is often limited to the generic assess- ment: serious or not serious. With a history of sig- nificant trauma, any persistent chest pain should be considered serious.

Either way, the heart muscle is ischemic and not getting enough oxygen. If the condition persists, infarction will result. If the area of the heart that is ischemic includes a major branch of the electrical conduction system, a cardiac dysrhythmia may develop. Whether you refer to it as myocardial ischemia or heart attack, it is a major circulatory system problem with the anticipated problem of cardiogenic shock and death. The pain of myocardial ischemia can present in a variety of ways: from the classic substernal pain radiating to the jaw and left arm, to back or abdominal pain. The patient may also experience shortness of breath, sweating, and nausea. These symptoms can be caused by the parasympathetic and sympathetic acute stress response to pain or to the effects of early cardiogenic shock. Of these, the most predictive sign and symptom for myocardial ischemia are sweating and radiation of pain to either arm. Of course, these same symptoms can be caused by indigestion, chest wall muscle spasm, altitude adjustment, respiratory infection, and a host of other less serious problems.

General Principles

Chest Pain

• Myocardial ischemia • Stable angina • Respiratory infection • Chest wall muscle strain • Chest wall contusion • Esophageal spasm • Pulmonary embolus • Etc.

Serious or Not Serious?

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Myocardial Ischemia In the absence of trauma, the type of chest pain that is most worrisome is the pain of myocardial ischemia. The mechanism for myocardial isch- emia may be an acute clot or spasm in a coronary artery or it may be a chronic coronary artery con- striction that prevents adequate blood flow to the heart muscle when oxygen demand is increased.