Acute Coronary Syndromes Flashcards

A 62-year-old male presents with severe, crushing substernal chest pain that started 45 minutes ago. His SpO2 is 95% on room air. A 12-lead ECG is obtained and shows ST-segment elevation in leads II, III, and aVF. His blood pressure is 88/50 mmHg and heart rate is 50 bpm. Lungs are clear to auscultation. Which of the following medications is contraindicated?

Answer: Nitroglycerin

Nitroglycerin is contraindicated in patients with hypotension (systolic blood pressure < 90 mmHg), bradycardia (< 50 bpm), and suspected right ventricular infarction. This patient's ECG findings (ST elevation in II, III, aVF) are consistent with an inferior wall MI, which has a high likelihood of right ventricular involvement. His hypotension and bradycardia are further contraindications to nitroglycerin administration, as it can worsen these conditions by reducing preload.

What is the recommended initial dose of non-enteric coated, chewable aspirin for an adult patient with a suspected Acute Coronary Syndrome?

Answer: 162 to 325 mg

The ACLS guidelines recommend a single dose of 162 to 325 mg of non-enteric coated aspirin to be chewed by patients with suspected ACS as soon as possible. Chewing the aspirin allows for more rapid absorption. This early administration of aspirin has been shown to reduce mortality.

A patient with ST-segment elevation myocardial infarction (STEMI) has ongoing chest discomfort despite receiving aspirin and three doses of sublingual nitroglycerin. Which of the following is the most appropriate next step for pain management according to ACLS guidelines?

Answer: Administer intravenous morphine sulfate.

For patients with STEMI whose chest discomfort is not relieved by nitroglycerin, intravenous morphine sulfate is the analgesic of choice. Morphine not only relieves pain but also causes venodilation, which reduces ventricular preload and myocardial oxygen demand. However, it should be used cautiously, especially in patients with hypotension or suspected right ventricular infarction.

Which of the following is the primary goal of treatment for a patient diagnosed with a STEMI?

Answer: Rapid reperfusion of the infarct-related artery

The cornerstone of treatment for STEMI is early and rapid reperfusion of the occluded coronary artery. This is most commonly achieved through percutaneous coronary intervention (PCI) with a goal of door-to-balloon time of 90 minutes or less, or with fibrinolytic therapy if PCI is not readily available, with a goal of door-to-needle time of 30 minutes or less. Restoring blood flow limits infarct size and improves outcomes.

A 55-year-old female presents to the emergency department with chest pain. A 12-lead ECG is performed within 10 minutes of arrival. Which of the following ECG findings is most indicative of an ST-segment elevation myocardial infarction (STEMI)?

Answer: New Left Bundle Branch Block (LBBB)

In a patient with symptoms of acute coronary syndrome, a new or presumably new Left Bundle Branch Block (LBBB) is considered a STEMI equivalent and should be treated with the same urgency as a patient with ST-segment elevation. While ST depression and T-wave inversion can indicate ischemia (NSTE-ACS), and Q waves suggest a previous infarction, a new LBBB in the setting of ischemic symptoms necessitates immediate reperfusion therapy.

According to the ACLS algorithm for Acute Coronary Syndromes, supplemental oxygen should be administered to a patient if their oxygen saturation (SpO2) is below what threshold?

Answer: 90%

Current ACLS guidelines recommend initiating supplemental oxygen therapy for patients with ACS only if their oxygen saturation is less than 90%. Routine use of supplemental oxygen in patients with normal oxygen saturation has not been shown to be beneficial and may even be harmful.