A 55-year-old man presents to the emergency department with worsening dyspnea over the past 48 hours. He recently had a cold that kept him home from work for the past week. He has a past medical history of diabetes, obesity, and hypertension. He had his Achilles tendon repaired 4 weeks ago and he has been less mobile. His temperature is 99.2°F (37.3°C), blood pressure is 150/85 mmHg, pulse is 82/min, respirations are 16/min, and oxygen saturation is 100% on room air. Physical exam is notable for dyspnea provoked by walking short distances. Jugular venous distension is noted on exam. The patient’s blood pressure is 130/70 mmHg during inspiration. A bedside echocardiogram demonstrates impaired diastolic filling with normal ventricular contractility. An ECG is performed as seen in Figure A. Which of the following is the most likely diagnosis?
Restrictive cardiomyopathy
Myocardial infarction
Constrictive pericarditis
Pulmonary embolism
Constrictive pericarditis
This patient is presenting with a preceding viral illness, dyspnea, jugular venous distension, pulsus paradoxus (blood pressure drop from 150/85 to 130/70 mmHg during inspiration), an echocardiogram with impaired diastolic filling, and diffuse ST elevation with PR depression on ECG. This constellation of symptoms is concerning for constrictive pericarditis.

Constrictive pericarditis occurs when the pericardium becomes thickened and fibrotic. In contrast to other types of pericarditis, in constrictive pericarditis, there is impaired diastolic filling and thus impaired cardiac function. There are many possible etiologies of constrictive pericarditis including infection, inflammatory conditions, or idiopathic. Patients will present with dyspnea, hypotension, tachycardia, a pericardial friction rub, and positional chest pain (usually worsened by laying back and relieved by leaning forward). Patients may also demonstrate jugular venous distension, lower extremity edema, worsening dyspnea, and congestive hepatopathy. ECG may demonstrate diffuse ST elevation with PR depression, and an echocardiogram will demonstrate impaired diastolic filling and may demonstrate a thickened pericardium. The diagnosis can be supported with pulsus paradoxus (a drop of blood pressure by > 10 mmHg during inspiration).

Welch reviews constrictive pericarditis. He discusses constrictive pericarditis and how the inelastic pericardium inhibits cardiac filling possibly causing unexplained heart failure. Welch notes making the diagnosis is very challenging and requires meticulous echocardiograph assessment.

Figure/Illustration A demonstrates diffuse ST elevation (blue arrows) with PR depression (black arrows). This is consistent with pericarditis.

Incorrect Answers:
Answer A: Cardiac tamponade can occur after trauma, in the setting of infection, or in the setting of autoimmune disease and is more likely to occur with a rapid accumulation of pericardial fluid. While pulsus paradoxus would be present in this condition, muffled heart sounds and electrical alternans would be more likely to be seen on ECG. Echocardiography would demonstrate an echogenic rim of fluid around the heart.

Answer C: Myocardial infarction presents with chest pain, dyspnea, hypotension, tachycardia, and ST elevation in a vascular distribution. Note that this patient’s ST elevation is diffuse and there is no reciprocal ST depression. Moreover, the pattern of chest pain in myocardial infarction is typically exertional and not positional.

Answer D: Pulmonary embolism may present with pleuritic chest pain, shortness of breath, tachycardia, hypoxia, hemoptysis, a history of hypercoagulability, and recent stasis or surgery (such as this patient’s recent Achilles tendon surgery). It can cause obstructive shock leading to hypotension and tachycardia. Note that right heart strain and sinus tachycardia would be seen on ECG.

Answer E: Restrictive cardiomyopathy presents very similarly to restrictive pericarditis. Note that in restrictive cardiomyopathy, patients will also have impaired diastolic filling; however, it is due to a myocardium that will not expand rather than the pericardium impairing filling. It can occur secondary to conditions such as amyloidosis or hemochromatosis as well as other chronic inflammatory states. The ECG findings are nonspecific but may include low voltage QRS complexes, ST segment changes, T wave changes, bundle branch blocks, and pathologic Q waves (abnormally deep and wide Q waves). The diagnosis can be supported with an ultrasound demonstrating impaired diastolic filling and possible myocardial speckling if a protein (amyloid) is present and deposited in the myocardial wall. The diagnosis can only definitively be confirmed with a biopsy which is highly invasive.

Bullet Summary:
Restrictive pericarditis presents with chest pain that is positional, pulsus paradoxus, a friction rub, and diffuse ST elevation with PR depression on ECG.