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

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Wilderness and Rescue Medicine

Treatment of Myocardial Ischemia “Time is myocardium” is the mantra of treatment. The sooner the ischemia can be reversed, the less heart muscle will be damaged and the better the patient’s chance for survival. This means an urgent evacuation, even if the patient cannot present to definitive medical care within the 2-hour window for clot-dissolving treatment. The ideal evacuation would not increase the stress or level of exertion for your patient. You may find yourself choosing between a walking evacuation that takes an hour and a carryout that may take several hours. You should favor the route that will access advanced life support (ALS) care as soon as possible while causing the least increase in activity and myocardial oxygen demand.

General Principles

Myocardial Ischemia

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Signs and Symptoms: • Chest pain with radiation • Shell/core effect, sweating • Elevated respiratory rate • Pulse may be variable Anticipate: • Myocardial infarction • Dysrhythmia • Cardiogenic shock

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Risk Factors Where evacuation to medical care will be a high- risk operation, you need to be able to decide whether the complaint of chest pain indicates a truly serious problem. To help with this decision, you can evaluate the patient’s risk factors for coro- nary artery disease.

General Principles

Myocardial Ischemia

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Specific Treatment: • Assist with nitroglycerin as prescribed • Give one adult aspirin • PROP • Gentle but urgent evacuation: • activity increases myocardial oxygen demand • time increases infarction • ALS care as soon as possible

Serious Chest Pain Myocardial Ischemia

General Principles

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Risk Factors: • Hypertension

• High blood cholesterol • Male over 40 years old • Post menopausal female • Smoking, obesity, diabetes

* “Time is myocardium…you should favor the route that will access ALS care as soon as possible…while causing the least increase in myocardial oxygen demand ”

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• Family or personal history of heart disease • Recreational use of amphetamines or cocaine

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If your patient is not already taking it daily, give one adult aspirin tablet (325 mg) or four baby aspi- rin (81 mg) by mouth. This reduces the tendency of the blood to clot, which may reduce ischemia in heart muscle. If the patient is currently taking other heart medication, like nitroglycerin, assist him or her in taking it according to directions. Stable Angina Your patient may give a history of stable angina— chest pain with exertion that resolves with rest. This develops when physical exertion increases the myocardial oxygen demand beyond the abil- ity of chronically narrowed coronary arteries to supply it. The relative ischemia is temporary, assuming that the patient can reduce activity and oxygen demand.

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Any patient with chest pain and a collection of risk factors should be considered at elevated risk for myocardial infarction and cardiac arrhyth- mia. Risk factors include disease states, genetics, medications, and lifestyle factors that contribute to narrowing and inflammation of the arteries supplying the heart. The more risk factors that your patient has, the more worried about his chest pain you should be. The most significant, at least in men, seems to be family or personal history of heart disease, and diabetes.