A 46-year-old woman comes to the office due to frequent episodes of "choking" at night for the past 3 months. She wakes up in the middle of the night and is unable to "catch her breath." The symptoms subside slowly after she gets up and walks around. She has also experienced occasional palpitations. The patient is otherwise physically active and walks on a treadmill 5 times a week for 30-45 minutes. Other medical problems include rheumatic fever at age 12, hypertension, depression, fibromyalgia, and non-Hodgkin lymphoma treated with combination chemotherapy 10 years ago. She is a lifelong nonsmoker.
Temperature is 37.2 C (99 F) , blood pressure is 122/80 mm Hg, pulse is 92/min, and respirations are 14/min. The lungs are clear to auscultation. Cardiac examination reveals a loud S1 and a "snapping" sound shortly after S2. There is a 2/6 ejection-type systolic murmur best heard over the second right intercostal space. There is also a faint mid-diastolic murmur heard over the cardiac apex. The remainder of the physical examination is unremarkable.
A transthoracic echocardiogram shows normal left ventricular size and function with an ejection fraction of 60%. The left atrium is moderately dilated. The mitral valve leaflets appear thickened with restricted opening. The estimated mitral valve area is 1.8 cm² (normal: 4-6 cm²) , consistent with moderate mitral stenosis. The aortic valve is sclerotic with mild restriction of leaflet motion and there is evidence of mild aortic stenosis. The pulmonary artery systolic pressure appears to be normal. ECG is shown in the exhibit.
Which of the following is the best next step in evaluating this patient's current symptoms?

Question

A 46-year-old woman comes to the office due to frequent episodes of "choking" at night for the past 3 months. She wakes up in the middle of the night and is unable to "catch her breath." The symptoms subside slowly after she gets up and walks around. She has also experienced occasional palpitations. The patient is otherwise physically active and walks on a treadmill 5 times a week for 30-45 minutes. Other medical problems include rheumatic fever at age 12, hypertension, depression, fibromyalgia, and non-Hodgkin lymphoma treated with combination chemotherapy 10 years ago. She is a lifelong nonsmoker.
Temperature is 37.2 C (99 F) , blood pressure is 122/80 mm Hg, pulse is 92/min, and respirations are 14/min. The lungs are clear to auscultation. Cardiac examination reveals a loud S1 and a "snapping" sound shortly after S2. There is a 2/6 ejection-type systolic murmur best heard over the second right intercostal space. There is also a faint mid-diastolic murmur heard over the cardiac apex. The remainder of the physical examination is unremarkable.
A transthoracic echocardiogram shows normal left ventricular size and function with an ejection fraction of 60%. The left atrium is moderately dilated. The mitral valve leaflets appear thickened with restricted opening. The estimated mitral valve area is 1.8 cm² (normal: 4-6 cm²) , consistent with moderate mitral stenosis. The aortic valve is sclerotic with mild restriction of leaflet motion and there is evidence of mild aortic stenosis. The pulmonary artery systolic pressure appears to be normal. ECG is shown in the exhibit.
Which of the following is the best next step in evaluating this patient's current symptoms?

Quizplus · Accepted Answer

This patient has a moderate degree of mitral stenosis and mild aortic stenosis, most likely due to rheumatic heart disease. Mitral stenosis progresses slowly and the majority of patients remain asymptomatic for an extended period of time. Atrial fibrillation (AF) commonly develops in patients with mitral stenosis and can lead to rapid clinical deterioration and symptomatic heart failure in previously asymptomatic patients. Mitral stenosis complicated by AF results in loss of effective atrial contraction in the setting of an already shortened left ventricular diastolic filling time. This leads to a rapid increase in the transmitral pressure gradient and consequent symptom development (eg, dyspnea, cough, hemoptysis). This patient's ECG shows normal sinus rhythm; however, she is most likely experiencing episodes of AF causing pulmonary edema as she lays supine at night. Therefore, a portable cardiac event monitor to investigate for paroxysmal AF is most appropriate. (Choice B) CT scan of the chest is useful to diagnose acute pulmonary embolism or enlarged mediastinal lymph nodes from recurrent lymphoma. However, these diagnoses are less likely in this patient given the prominence of her dyspnea when lying supine and the lack of systemic symptoms (eg, fever, chills, weight loss). (Choice C) Exercise stress testing would likely be unrevealing in this patient who does not have any exertional symptoms and is able to exercise 5 days a week for 30-45 minutes. (Choice D) A split-night sleep study allows for diagnosis of sleep-related breathing disorders (eg, obstructive sleep apnea) and titration of continuous positive pressure settings in the same night. However, this patient's paroxysmal nocturnal dyspnea and diastolic murmur on examination are more suggestive of progressive mitral stenosis complicated by paroxysmal AF, which is best diagnosed with cardiac event monitoring. (Choice E) Transesophageal echocardiogram is typically performed for better visualization of the mitral valve prior to percutaneous balloon valvotomy for alleviation of severe mitral stenosis. However, such a procedure is not currently indicated in this patient with moderate mitral stenosis and no significant exercise limitation at baseline. Educational objective: Patients with mitral stenosis frequently develop atrial fibrillation as the disease progresses. The loss of atrial contraction with atrial fibrillation can lead to a rapid increase in left atrial pressure, and can cause rapid decompensation with symptomatic heart failure in otherwise asymptomatic patients. __________ References: Echocardiographic features of patients with paroxysmal atrial fibrillation. (http://www.ncbi.nlm.nih.gov/pubmed/17597421) Arrhythmias in the natural history of mitral stenosis. (http://www.ncbi.nlm.nih.gov/pubmed/1615736)

A 46-Year-Old Woman Comes to the Office Due to Frequent