Acute Myocardial Infarction 3

Question

Vignette:

A 65-year-old man presents to the emergency department with severe chest pain. He has a history of smoking and hypertension. Electrocardiogram reveals ST segment elevations in leads II, III, and aVF. He is diagnosed with an acute myocardial infarction and is given aspirin, nitroglycerin, and a beta-blocker. Despite these interventions, his pain persists. He develops hypotension, tachycardia, and a new murmur is heard on auscultation. His jugular venous pressure is elevated and his heart sounds are distant. An echocardiogram is ordered. Which of the following is the most likely diagnosis?

Choices

A) Aortic stenosis

B) Mitral regurgitation

C) Cardiac tamponade

D) Pulmonary embolism

E) Ventricular septal defect

Answer

C) Cardiac tamponade

Explanation

This patient's persistent chest pain, hypotension, tachycardia, elevated jugular venous pressure, distant heart sounds, and new murmur following a myocardial infarction suggest a mechanical complication. These signs are consistent with cardiac tamponade, which can occur due to rupture of the free wall of the left ventricle, leading to blood accumulation in the pericardial space. This can impede cardiac filling and lead to decreased cardiac output. Cardiac tamponade is a medical emergency that requires immediate intervention.

Aortic stenosis (Choice A) and mitral regurgitation (Choice B) are valvular heart diseases that would not typically cause these signs and symptoms acutely following a myocardial infarction. Pulmonary embolism (Choice D) can cause hypotension and tachycardia, but would not cause elevated jugular venous pressure or distant heart sounds. Ventricular septal defect (Choice E) is a potential complication of myocardial infarction, but it would not cause the constellation of signs seen in this patient.