Cardiovascular Emergencies Flashcards

A patient presents with crushing substernal chest pain and ST-segment elevation in leads II, III, and aVF. Which coronary artery is most likely occluded?

Answer: Right coronary artery

ST elevation in II, III, and aVF indicates an inferior wall MI, typically caused by right coronary artery occlusion.

In a patient with an inferior wall MI, why should nitroglycerin be administered cautiously?

Answer: Right ventricular involvement makes the patient preload-dependent

Inferior MIs often involve the right ventricle, and nitroglycerin-induced preload reduction can cause severe hypotension.

Which laboratory marker is most specific for myocardial injury?

Answer: Troponin I

Troponin I is highly specific to cardiac muscle and is the preferred marker for diagnosing myocardial injury.

A patient with an acute MI develops a new harsh holosystolic murmur and pulmonary edema 3 days post-infarction. What complication is most likely?

Answer: Papillary muscle rupture

A new holosystolic murmur with acute pulmonary edema post-MI suggests papillary muscle rupture causing acute mitral regurgitation.

What is the primary goal of fibrinolytic therapy in STEMI when PCI is unavailable?

Answer: Dissolve the occluding thrombus and restore perfusion

Fibrinolytics break down the clot occluding the coronary artery to restore myocardial blood flow.

Which finding is an absolute contraindication to fibrinolytic therapy?

Answer: Recent ischemic stroke within 3 months

Recent ischemic stroke within 3 months is an absolute contraindication due to high bleeding/conversion risk.

A patient post-MI is started on a beta-blocker. What is the primary rationale?

Answer: Reduce myocardial oxygen demand and prevent arrhythmias

Beta-blockers lower heart rate and contractility, reducing oxygen demand and the risk of lethal arrhythmias.