A 70-year-old man presents to his primary care physician with worsening shortness of breath on minimal exertion over the past 6 months. He has a history of coronary artery disease and severe mitral valve regurgitation, which had been treated with coronary bypass grafting and mechanical mitral valve replacement 6 years earlier. He has permanent atrial fibrillation. His cardiac risk factors include type 2 diabetes mellitus, obesity, hypertension, and prior nicotine dependence (quit smoking 10 years ago after a 30-pack-year history).
Due to his multiple morbidities, the differential diagnosis is broad. A thorough assessment of the patient’s history and physical exam, however, can often appropriately direct the evaluation.
On further questioning, the patient describes a gradual onset of his shortness of breath; currently, he cannot master 1 flight of stairs without getting severe symptoms (New York Heart Association class III). He denies typical chest pain, palpitations, fever, or chills. Since cardiac rehabilitation after his open-heart surgery, he has not performed regular exercise.
On physical exam, his vital signs are within normal limits (blood pressure 135/75 mm Hg, heart rate 75 bpm [irregularly irregular], respiratory rate 14 breaths/min, normal temperature). The most pertinent positive finding on his physical exam is a 3/6 harsh, medium-pitched, holosystolic murmur, which is best heard at the apex and the upper left sternal border. He has mild to moderate bibasilar crackles on posterior pulmonary auscultation and +1 to 2 pretibial edema. His jugular venous pressure is elevated to the mid-neck (5 cm above the jugulum, corresponding to 7-8 mm Hg assumed central venous pressure). His laboratory workup is unremarkable, with a normal complete blood count and metabolic panel and a hemoglobin A1c of 7%.
He is on a stable medical regimen that includes aspirin, furosemide, β-blocker therapy, and an oral antidiabetic.
After this initial assessment, his differential diagnoses are as follows:
Progressive coronary artery disease; his shortness of breath could represent an angina equivalent in the setting of diabetes mellitus.
Severe physical deconditioning in the setting of morbid obesity.
Mitral valve regurgitation (ie, failing mitral valve prosthesis leading to either transvalvular or paravalvular regurgitation).
Pulmonary disease such as chronic obstructive pulmonary disease/emphysema; he has a long history of smoking.
Diastolic dysfunction associated with atrial fibrillation and episodes of poor rate control could contribute to his shortness of breath.
CARDIOLOGY WORKUP AND MANAGEMENT
In a patient who has a history of mitral valve replacement who presents with increasing shortness of breath and a loud holosystolic murmur, a transthoracic echocardiogram will be key in the initial workup. The echocardiogram provides the primary care physician and cardiologist with valuable information on the patient’s left and right ventricular systolic function, diastolic function, noninvasive assessment of pulmonary pressures, and valvular function. If the transthoracic echocardiogram does not reveal any significant pathology, further ...