Review Question - QID 217284

This woman presenting with symptoms of right heart failure (fatigue and lower extremity swelling) as well as Kussmaul sign (increased jugular venous distention with inspiration), pulsus paradoxus (inspiratory decline in systolic blood pressure > 10mmHg), and a pericardial knock likely has a diagnosis of constrictive pericarditis secondary to chest irradiation. Cardiac computed tomography (CT) in patients with constrictive pericarditis often demonstrates pericardial thickening and calcifications.

Constrictive pericarditis is a disease of the pericardium in which the pericardial tissue progressively becomes fibrotic, calcified, and thickened due to an initial insult such as radiation therapy, open heart surgery, viral myocarditis, connective tissue disease, or tuberculosis. This process results in constriction of the ventricles, leading to impaired ventricular filling and the insidious development of right-sided heart failure with symptoms of dyspnea on exertion, lower extremity edema, and chest pain. Physical exam findings include Kussmaul sign, pulsus paradoxus, pericardial knock, ascites, and lower extremity edema. Diagnosis is best made with an echocardiogram demonstrating increased pericardial thickness. A cardiac CT can confirm the diagnosis and shows pericardial thickening and calcifications. Initial management is a trial of diuretic therapy. Patients with disease refractory to diuretics can be considered for pericardiectomy for long-term treatment.

Welch provides a comprehensive review of the diagnosis, management, and clinical outcomes of constrictive pericarditis. Of note, patients with radiation therapy as the etiology of constrictive pericarditis have poor survival rates compared to other etiologies, possibly due to underlying effects of cancer and widespread effects of radiation on both heart and lung tissue.

Incorrect Answers:
Answer 1: Enlarged cardiac silhouette on chest radiograph is classically seen in patients with severe cardiac tamponade and presents with Beck triad of jugular venous distention, hypotension, and muffled heart sounds. Although cardiac tamponade can occur as a sequelae of untreated pericarditis, physical exam would reveal muffled heart sounds rather than a pericardial knock, and electrical alternans on ECG.

Answer 2: Focal ST segment elevations on ECG would be expected in an ST elevation myocardial infarction (STEMI) which would most commonly presents with sudden chest pain radiating to the left arm. Widespread ST-segment elevations, rather than focal ST segment elevations, can be seen in constrictive pericarditis.

Answer 4: Reduced ejection fraction on echocardiogram is most often a sign of left-sided or systolic heart failure, rather than right-sided or diastolic heart failure as seen in constrictive pericarditis. Other signs of left-sided heart failure include pulmonary edema, orthopnea, and paroxysmal nocturnal dyspnea.

Answer 5: Widespread ST segment depression on ECG is characteristic of diffuse subendocardial infarctions as can be seen in non-ST elevation myocardial infarctions (NSTEMIs). In constrictive pericarditis, widespread ST segment elevation or PR segment depression can be seen.

Bullet Summary:
Patients undergoing radiation therapy to the chest are at risk for developing constrictive pericarditis which presents with signs of right heart failure, Kussmaul sign, pulsus paradoxus, pericardial knock, and pericardial thickening on echocardiogram and cardiac computed tomography.