A 30-year-old woman comes to the emergency department with intermittent dizziness and unsteadiness for the last 2 weeks. Since yesterday, her symptoms appear to be worse and she has had several near-syncope episodes. The patient has no chest pain but has mild shortness of breath. Medical history is significant for obesity, intermittent asthma, and chronic cough. She had an episode of uveitis 6 months ago that was treated with topical therapy. She does not use tobacco and drinks alcohol only on special occasions. The patient has no pets and has been monogamous with a single partner for the last 3 years. On physical examination, her temperature is 37.2 C (98.9 F), blood pressure is 126/76 mm Hg, pulse is 36/min, and respirations are 16/min. There are no heart murmurs. ECG shows sinus rhythm with 2:1 atrioventricular block and left bundle branch block. Chest x-ray reveals bilateral midfield lung opacities. Which of the following is the most likely diagnosis?

Question

A 30-year-old woman comes to the emergency department with intermittent dizziness and unsteadiness for the last 2 weeks.  Since yesterday, her symptoms appear to be worse and she has had several near-syncope episodes.  The patient has no chest pain but has mild shortness of breath.  Medical history is significant for obesity, intermittent asthma, and chronic cough.  She had an episode of uveitis 6 months ago that was treated with topical therapy.  She does not use tobacco and drinks alcohol only on special occasions.  The patient has no pets and has been monogamous with a single partner for the last 3 years.  On physical examination, her temperature is 37.2 C (98.9 F), blood pressure is 126/76 mm Hg, pulse is 36/min, and respirations are 16/min.  There are no heart murmurs.  ECG shows sinus rhythm with 2:1 atrioventricular block and left bundle branch block.  Chest x-ray reveals bilateral midfield lung opacities.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient with a recent history of uveitis has mild dyspnea and a 2-week history of presyncope episodes likely due to conduction abnormalities, given her marked bradycardia with atrioventricular (AV) block and left bundle branch block. She most likely has sarcoidosis with cardiac involvement. Autopsy studies have suggested evidence of cardiac noncaseating granulomas in at least 25% of patients with sarcoidosis. However, only 5% of patients demonstrate signs or symptoms of cardiac involvement, suggesting that cardiac sarcoidosis is underdiagnosed or often remains subclinical. Infiltration of noncaseating granulomas leads to surrounding inflammation and can result in conduction defects (complete AV block is most common), restrictive cardiomyopathy (early manifestation), dilated cardiomyopathy (late manifestation), valvular dysfunction, and heart failure. Sudden cardiac death can occur due to complete AV block or ventricular arrhythmia. Cardiac sarcoidosis should be suspected in any young patient (age <55) with unexplained second- or third-degree heart block or when ECG changes occur in a patient with known or suspected systemic sarcoidosis (eg, dyspnea with midfield lung opacities, uveitis). Definitive diagnosis can be challenging due to poor sensitivity of endomyocardial biopsy, but a combination of imaging findings, ECG findings, and history often strongly suggests the diagnosis. (Choice A) Coronary artery disease (CAD) can lead to ischemia-related conduction defects and heart failure. However, CAD would be unusual in this young woman, and her history of uveitis makes cardiac sarcoidosis more likely. (Choice B) AV block can rarely occur in hyperthyroidism, but tachyarrhythmias are more common. Patients with hyperthyroidism typically have other symptoms such as weight loss, increased appetite, anxiety, and heat intolerance, which are not present in this patient. (Choice C) Lyme carditis can occur 1-2 months after infection with Borrelia burgdorferi, and AV block is the most common abnormality seen. However, this patient's lack of joint pain and a preceding rash make Lyme disease less likely. (Choice E) Symptomatic viral myocarditis typically presents with symptoms of heart failure such as progressive dyspnea, lower extremity swelling, and orthopnea. High-grade AV block is less common. Educational objective: Cardiac sarcoidosis is a disease of noncaseating granuloma infiltration of the myocardium and can result in serious arrhythmia, cardiomyopathy, heart failure, and sudden cardiac death. References: Cardiac sarcoidosis-state of the art review. (http://www.ncbi.nlm.nih.gov/pubmed/26885492)

A 30-Year-Old Woman Comes to the Emergency Department with Intermittent