Can You Diagnose the Cause of This Patient’s Dyspnea?
Author:
Andrew Freeman, MD
National Jewish Health
A 47‑year‑old woman with a normal body mass index presented to her primary care physician with dyspnea, which she noted when she was playing with her children outside. She originally thought it was nothing serious and thought it might have been a cold. The primary care physician ordered chest radiography and spirometry, the results of which were unremarkable.
The primary care physician also ordered a complete blood cell count and an exercise stress test; the patient’s white blood cell count did not suggest any infection was present, and the results from the stress test were unremarkable. From there, the primary care physician referred the patient to a pulmonologist, who subsequently performed a pulmonary function test.
The only notable finding of the pulmonary function test was that the patient’s diffusion capacity for carbon monoxide (DLCO) was slightly low. When the pulmonologist listened to the patient’s heart/chest, he thought that S2 was somewhat loud. Therefore, the patient was referred to a cardiologist and underwent echocardiography.
The echocardiogram showed that the right side of the patient’s heart was mildly enlarged and borderline in its function. The patient’s TAPSE (tricuspid annular plane systolic excursion) score was about 15 mm, whereas the threshold is about 16 mm. Her right ventricular systolic pressure estimate was in the 60s (normal range, 16-39 mm Hg), but she had preserved left ventricular function.
ANSWER: PULMONARY HYPERTENSION
When a provider hears a louder S2, most commonly it is associated with pulmonary hypertension. Whenever someone presents with dyspnea, there should be a relatively low threshold to order echocardiography if nothing obvious shows up on routine test results or examination.
The diagnosis of pulmonary hypertension should always be on the differential, because so many people walk around with dyspnea and receive very late diagnoses because they have not seen the appropriate specialist. In this case, a very astute pulmonologist raised a red flag and suggested echocardiography.
In addition, one cannot actually make the diagnosis of pulmonary hypertension without a right heart catheterization, which is the only way to make the diagnosis. Once the cardiologist saw the patient and saw the echocardiogram, a right heart catheterization was ordered. Then pulmonary hypertension was diagnosed.
The echocardiogram was the real clincher in making this diagnosis. Often, providers just forget to order them. Even worse is when a provider orders echocardiography, and the findings suggest pulmonary hypertension, but the provider just treats the patient based on the echocardiogram, which is the wrong thing to do. Echocardiograms are really just an estimate, and sometimes they are wrong. Therefore, results of echocardiography should be used in addition to patient history and other test results.
The message here is that among younger women with dyspnea that is unexplained, pulmonary hypertension should always be on the differential.
Obesity hypoventilation was unlikely because the patient was not obese.
Coronary artery disease/anginal equivalent was less likely because the patient was young and relatively healthy, and the results of the stress test were unremarkable.
Emphysema and asthma were less likely because the patient had no history of smoking, and the results of the pulmonary function tests and spirometry were unremarkable.
Obstructive sleep apnea was ruled out after results of a sleep‑apnea evaluation were not remarkable.
PATIENT OUTCOME
The patient was started on diuretic therapy with a pulmonary artery vasodilator, tadalafil, and had marked improvement. A second agent will be started shortly.
Andrew M. Freeman, MD, FACC, FACP, is an associate professor, director of Cardiovascular Prevention and Wellness, and director of Clinical Cardiology & Operations in the Division of Cardiology in the Department of Medicine at National Jewish Health in Denver, Colorado.