Case Presentation: A 47-year-old woman presented with two days of shortness of breath and hemoptysis following two weeks of nonproductive cough. Associated symptoms included bilateral lower extremity edema and malaise. She was a nursing home resident and former smoker, but had no other risk factors for tuberculosis. Medical history included systolic heart failure, ESRD, COPD, anxiety, and morbid obesity.
Her vital signs were within normal limits. Physical examination revealed bibasilar crackles and pitting pedal edema, but no murmurs or JVD. Chest x-ray showed bilateral pleural effusions and pulmonary edema. Contrasted lung CT was negative for pulmonary embolism, but did reveal multifocal pneumonia and pleural effusion. Her last transthoracic echocardiogram five months prior showed an ejection fraction of 35% without valvular disease.
Therapeutic thoracentesis and a course of antibiotics for hospital-acquired pneumonia only mildly improved her dyspnea. Her edema and bibasilar crackles failed to improve. This persistent volume overload was attributed to a malfunctioning dialysis catheter, which was replaced. Her volume status still persisted, and her dyspnea and hemoptysis recurred.
A repeat transthoracic echocardiogram revealed a new finding of severe aortic regurgitation with an unchanged ejection fraction. She ultimately received an aortic valve replacement, after which her volume status and respiratory symptoms significantly improved.
Discussion: Hospitalists commonly encounter patients with dyspnea, and the vast differential diagnosis presents a diagnostic challenge. This can be even more complex in a patient with several comorbidities, such as in this case. The patient had many potential causes of her symptoms, including multifocal pneumonia, ESRD with suboptimal ultrafiltration, COPD, and even anxiety, obesity, and physical deconditioning. By focusing on these conditions, the diagnosis of aortic regurgitation was delayed. It is important to remain cognizant that the presence of a known disease entity does not guarantee the symptoms are due to that condition. After the diagnosis was made, aortic valve replacement was performed, as it is indicated for symptomatic patients with severe aortic regurgitation regardless of left ventricular systolic function.
Heuristics often influence the practice of medicine. While useful for diagnosis, they can also lead to biases in clinical reasoning. Due to anchoring and confirmation bias, this patient’s symptoms were attributed to her known conditions, and further etiologies were not sought out until later. Cognizance of potential biases caused by heuristics may help prevent premature closure and other errors in a hospitalist’s diagnosis and treatment.
This case also illustrates the importance of physical exam interpretation. Aortic regurgitation is classically associated with a diastolic murmur. However, diastolic murmurs only have a sensitivity of 6% and specificity of 98% for aortic regurgitation. The absence of cardiac murmur on auscultation in conjunction with the aforementioned heuristics delayed the diagnosis.
Conclusions: This case is a reminder that heuristics are a reality of clinical decision-making, and although they often help lead to the correct diagnosis, the practicing hospitalist should be aware of potential biases that could adversely affect clinical practice.