3.1 Cardiac Emergencies
Key Takeaways
- Acute coronary syndrome (ACS) presentations include classic chest pressure, but women, older adults, and diabetic patients more often present atypically with dyspnea, fatigue, or epigastric discomfort
- AEMT scope for suspected ACS centers on oxygen titrated to need, aspirin for the patient without contraindications, and assisting with the patient's prescribed nitroglycerin per protocol
- Acute left-heart failure produces pulmonary edema with crackles, dyspnea, and frothy sputum, whereas right-heart failure produces dependent edema and jugular venous distention
- Cardiogenic shock is pump failure with hypotension, weak pulses, cool clammy skin, and altered mentation despite adequate volume — fluid boluses must be cautious
- Nitroglycerin is generally withheld when systolic blood pressure is low or when the patient has recently used a phosphodiesterase inhibitor such as a medication for erectile dysfunction
Cardiology and Resuscitation accounts for 11%-15% of the NREMT Advanced Emergency Medical Technician (AEMT) cognitive exam. Most cardiac questions are scenario based: the exam wants to see that you recognize a cardiac emergency early, prioritize life threats, and choose interventions that stay inside the AEMT scope of practice. This section focuses on the non-arrest cardiac emergencies you will see most often in the field and on the test.
Acute Coronary Syndrome (ACS)
Acute coronary syndrome (ACS) is an umbrella term for conditions caused by sudden reduced blood flow to the heart muscle, ranging from unstable angina to myocardial infarction (MI), commonly called a heart attack. The underlying problem is usually a ruptured plaque and clot in a coronary artery, which starves myocardium of oxygen.
Recognizing ACS
The classic presentation is substernal chest pressure or tightness, often radiating to the left arm, jaw, or back, with diaphoresis, nausea, and shortness of breath. However, the exam emphasizes atypical presentations, which are common in women, older adults, and patients with diabetes.
| Population | Common Atypical Presentation |
|---|---|
| Women | Fatigue, dyspnea, nausea, back or jaw discomfort |
| Older adults | Confusion, weakness, syncope, vague malaise |
| Diabetic patients | "Silent" MI with little or no chest pain |
Use the OPQRST mnemonic (Onset, Provocation, Quality, Region/Radiation, Severity, Time) to characterize the discomfort, and gather a SAMPLE history (Signs/symptoms, Allergies, Medications, Past history, Last oral intake, Events). Apply the cardiac monitor if your service uses one at the AEMT level and obtain a 12-lead where protocol and equipment allow, then transmit or relay findings so the receiving facility can prepare.
AEMT Management of Suspected ACS
AEMT interventions for suspected ACS are supportive and protocol driven:
- Position and reassure the patient; limit exertion and keep them calm.
- Oxygen titrated to need — administer to maintain an adequate oxygen saturation rather than routinely giving high-flow oxygen to every chest pain patient.
- Aspirin — for the patient with suspected cardiac chest pain and no contraindications (allergy, active bleeding, or other protocol exclusions), aspirin is given to be chewed because it reduces platelet aggregation. Follow your local protocol for the exact regimen.
- Nitroglycerin — AEMTs typically assist a patient with taking their own prescribed nitroglycerin (or administer per protocol). Nitroglycerin is a vasodilator that reduces cardiac workload and can relieve ischemic pain.
- Establish IV access within scope when transport and protocol indicate, and monitor vital signs frequently.
- Rapid transport to an appropriate facility, ideally one capable of definitive cardiac care.
Nitroglycerin Cautions
Nitroglycerin lowers blood pressure. Before assisting with it, confirm an adequate systolic blood pressure per your protocol's threshold, confirm the medication is the patient's own current prescription when assisting, and screen for recent use of a phosphodiesterase-5 (PDE-5) inhibitor — erectile dysfunction or pulmonary hypertension medications — because combining them with nitroglycerin can cause profound, dangerous hypotension. Reassess blood pressure after each dose.
Congestive Heart Failure and Pulmonary Edema
Congestive heart failure (CHF) occurs when the heart cannot pump effectively enough to meet the body's demands, causing fluid to back up. The exam expects you to distinguish left-sided from right-sided failure because the presentation and the priority intervention differ.
- Left-heart failure backs blood up into the lungs, producing acute pulmonary edema: severe dyspnea, orthopnea (worse when lying flat), anxiety, crackles (rales) on auscultation, and sometimes pink, frothy sputum. These patients are often hypertensive and use accessory muscles.
- Right-heart failure backs blood up into the systemic circulation, producing jugular venous distention (JVD), dependent (pedal/sacral) edema, and hepatic congestion.
AEMT Priorities in Acute Pulmonary Edema
The immediate problem is oxygenation and work of breathing. Sit the patient upright, provide oxygen titrated to maintain adequate saturation, and support ventilation. Continuous positive airway pressure (CPAP) is a key intervention for severe cardiogenic pulmonary edema where the AEMT is trained and protocol authorizes it; CPAP improves oxygenation and reduces the work of breathing. Establish IV access for monitoring, obtain vital signs and cardiac monitoring within scope, and transport promptly while reassessing respiratory status continuously.
Hypertensive Emergency
A hypertensive emergency is severely elevated blood pressure accompanied by signs of end-organ dysfunction — for example, altered mental status, severe headache, vision changes, chest pain, or acute pulmonary edema. It is distinguished from asymptomatic severe hypertension ("hypertensive urgency") by the presence of those end-organ signs.
AEMT field care is supportive: a calm environment, position appropriately, oxygen titrated to need, IV access for monitoring, frequent neurologic and vital-sign reassessment, and prompt transport. AEMTs do not aggressively lower blood pressure in the field; abrupt reduction can worsen organ perfusion. Watch for and treat associated emergencies such as stroke, ACS, or pulmonary edema, and consider stroke as a differential when neurologic signs are present.
Cardiogenic Shock
Cardiogenic shock is a state of inadequate tissue perfusion caused by pump failure, most often after a large MI. It is the most lethal cardiac emergency in this section.
| Finding | Cardiogenic Shock |
|---|---|
| Mental status | Anxious, confused, or decreasing level of consciousness |
| Skin | Cool, pale, clammy/diaphoretic |
| Pulse | Weak, often rapid; may be irregular |
| Blood pressure | Hypotensive (a late, ominous sign) |
| Lungs | May have pulmonary edema/crackles |
The pump cannot move blood, so simply pouring in IV fluid does not fix the problem and can worsen pulmonary edema. AEMT management is high-concentration support of oxygenation and ventilation as needed, cautious IV access, careful position, continuous monitoring, and rapid transport to a facility capable of definitive cardiac care. Use small, closely monitored fluid administration only if directed by protocol or medical direction, and reassess lung sounds and breathing after any fluid.
A 58-year-old woman reports unusual fatigue, mild shortness of breath, and nausea for the past hour. She denies chest pain. Her skin is pale and diaphoretic. Which conclusion is most appropriate?
Before assisting a patient with their prescribed nitroglycerin for chest pain, which finding would most strongly lead the AEMT to withhold the medication?
An AEMT assesses a hypotensive patient with cool, clammy skin, weak rapid pulses, crackles in both lung bases, and decreasing responsiveness following a suspected large MI. Which action is most appropriate?