A 23-year-old primigravida at 29 weeks gestation comes to the emergency department with sudden-onset severe shortness of breath. She woke up today with a fluttering sensation in her chest, which progressed to significant dyspnea, dry cough, and an inability to lie flat. Recently, the patient has had some exercise intolerance and tiredness, which she attributes to pregnancy. Her medical history is significant for recurrent sore throat requiring tonsillectomy as a child. She is a lifetime nonsmoker and does not use alcohol. The patient's lifestyle is mostly sedentary. She immigrated to the United States from India 5 years ago. Her blood pressure is 110/60 mm Hg and pulse is 144/min. The patient appears uncomfortable. An ECG shows atrial fibrillation with rapid ventricular response. Which of the following is the most likely diagnosis?

Question

A 23-year-old primigravida at 29 weeks gestation comes to the emergency department with sudden-onset severe shortness of breath.  She woke up today with a fluttering sensation in her chest, which progressed to significant dyspnea, dry cough, and an inability to lie flat.  Recently, the patient has had some exercise intolerance and tiredness, which she attributes to pregnancy.  Her medical history is significant for recurrent sore throat requiring tonsillectomy as a child.  She is a lifetime nonsmoker and does not use alcohol.  The patient's lifestyle is mostly sedentary.  She immigrated to the United States from India 5 years ago.  Her blood pressure is 110/60 mm Hg and pulse is 144/min.  The patient appears uncomfortable.  An ECG shows atrial fibrillation with rapid ventricular response.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's clinical presentation - cough, progressive dyspnea, and orthopnea - is consistent with pulmonary edema with rapid decompensation due to development of new atrial fibrillation (AF) with rapid ventricular response (RVR). Her history of recurrent sore throat and origin from a country with high incidence of rheumatic heart disease make rheumatic mitral stenosis the most likely diagnosis. Rheumatic mitral stenosis is an insidious progressive disease, and patients can remain asymptomatic for several years. During pregnancy, physiologic increases in heart rate and blood volume raise the transmitral gradient and left atrial pressure (at rest and during exercise). As seen in this patient, these changes often precipitate symptoms of fatigue, exercise intolerance, or dyspnea in previously asymptomatic patients with rheumatic mitral stenosis. These patients are also at increased risk of developing AF. The loss of an effective "atrial kick" and decrease in diastolic filling times seen with AF and RVR (ie, pulse >100/min) further increases left atrial pressure, with dramatic worsening of pulmonary congestion and pulmonary edema. (Choice A) Aortic insufficiency can result from rheumatic heart disease and present with heart failure and AF, but it is less common than mitral stenosis in women of childbearing age. (Choice B) Constrictive pericarditis presents as predominant right heart failure with elevated jugular venous pressure, hepatomegaly, ascites, and peripheral edema. Symptoms can be exacerbated during pregnancy due to increased blood volume and hypervolemia. (Choice C) Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disorder of cardiac sarcomere characterized by asymmetric left ventricular hypertrophy. Symptoms are attributed to dynamic left ventricular outflow tract (LVOT) obstruction, and dehydration and hypovolemia worsen LVOT obstruction and symptoms. Conversely, hypervolemia with pregnancy would be expected to reduce symptoms attributed to LVOT obstruction. HCM should be distinguished from hypertrophy due to other cardiovascular heart diseases (eg, hypertension, valvular, ischemic). (Choice E) Myocardial infarction is unlikely in a young woman with no other risk factors for coronary artery disease and with an ECG showing no ischemic changes. (Choice F) Peripartum cardiomyopathy (PPCM) causes rapid-onset systolic heart failure (fatigue, dyspnea, cough, pedal edema) at >36 weeks gestation or the early puerperium. This patient's medical and social history and symptom onset before 36 weeks gestation makes mitral stenosis more likely than PPCM. Also, AF with RVR is relatively rare in PPCM. Educational objective: Rheumatic mitral stenosis is an insidious progressive disease, and physiologic and hemodynamic changes during pregnancy can precipitate symptoms in previously asymptomatic patients. The development of new atrial fibrillation can further increase transmitral gradient and left atrial pressure, with dramatic worsening of pulmonary congestion and pulmonary edema. References: Management of severe mitral stenosis during pregnancy. (http://www.ncbi.nlm.nih.gov/pubmed/22155997)

A 23-Year-Old Primigravida at 29 Weeks Gestation Comes to the Emergency