Chest pain and acute coronary syndrome
Spotting it, the patients who hide it, aspirin, and the rules for nitroglycerin
Acute coronary syndrome (ACS) starts when a coronary artery narrowed by plaque is blocked by a clot. The muscle past the block runs short of oxygen. If the artery is not opened, that muscle dies. You cannot tell unstable angina from a heart attack in a living room, and you do not need to. Both are ACS, and both get the same care.
The classic picture
The patient describes pressure, squeezing, tightness or a weight on the chest, more often than sharp pain. It may spread to an arm, the jaw, the neck or the back. Sweating, nausea, shortness of breath and a sense that something is badly wrong come with it. Cool, clammy skin is a warning sign the heart is going into shock. Stable angina comes on with effort and eases within minutes of rest or nitroglycerin. Pain that arrives at rest, is new, lasts longer or no longer responds is treated as ACS.
The patients who hide it
Women, older adults and people with diabetes often have no chest pain at all. They call for sudden tiredness, shortness of breath, nausea, pain in the upper belly that feels like indigestion, an aching jaw or back, fainting. Keep a low threshold. If the story has no better explanation, treat it as the heart.
What an EMT does
- Rest. Position of comfort, calm voice, and no walking to the stretcher. Effort raises the heart's demand for oxygen.
- Oxygen for a low saturation, shortness of breath or signs of shock, per protocol. A comfortable patient with a normal saturation does not need a mask.
- Aspirin, 162 to 325 mg, chewed. It keeps platelets from adding to the clot. It is not for pain. Withhold it for a true aspirin allergy or active bleeding in the gut.
- The patient's own nitroglycerin, under the rules below.
- Call ALS and notify the hospital early. Acquire a 12-lead where local protocol allows. The destination should be able to open the artery.
- Keep the AED close. These patients can arrest in front of you.
Assisting with nitroglycerin
Nitroglycerin widens blood vessels, which eases the heart's workload. It also drops blood pressure, and that is the danger. Before you assist, every item on this list has to be true:
- It is prescribed to this patient and is not expired.
- The systolic pressure is above 90 to 100, by your protocol.
- The patient has not taken an erectile dysfunction drug such as sildenafil or tadalafil recently. Ask every patient, plainly and in private if you can. Some people take these drugs for lung conditions.
- The patient has had fewer than three doses for this episode.
The dose is 0.4 mg, a tablet or a spray under the tongue. Recheck the blood pressure before every dose and about five minutes after. Doses are five minutes apart, to a total of three. If the pressure drops or the patient turns dizzy and pale, lay the patient flat, give no more, and tell ALS and the hospital.
Aspirin is for the clot, not the pain. Nitroglycerin needs a good systolic pressure, no erectile dysfunction drug, the patient's own prescription, and no more than three doses in total.
Pressure cutoffs, the time window for erectile dysfunction drugs, oxygen targets and 12-lead use differ from one service to the next. Your local protocols and your medical director decide what you do on a real call.