Dyspnea is a common complaint in the emergency department where physicians
must accurately make a rapid diagnosis.
To assess the usefulness of history, symptoms, and signs along with
routine diagnostic studies (chest radiograph, electrocardiogram, and serum
B-type natriuretic peptide [BNP]) that differentiate heart failure from other
causes of dyspnea in the emergency department.
We searched MEDLINE (1966-July 2005) and the reference lists from retrieved
articles, previous reviews, and physical examination textbooks.
We retained 22 studies of various findings for diagnosing heart failure
in adult patients presenting with dyspnea to the emergency department.
Two authors independently abstracted data (sensitivity, specificity,
and likelihood ratios [LRs]) and assessed methodological quality.
Many features increased the probability of heart failure, with the best
feature for each category being the presence of (1) past history of heart
failure (positive LR = 5.8; 95% confidence interval [CI], 4.1-8.0);
(2) the symptom of paroxysmal nocturnal dyspnea (positive LR = 2.6;
95% CI, 1.5-4.5); (3) the sign of the third heart sound (S3) gallop
(positive LR = 11; 95% CI, 4.9-25.0); (4) the chest radiograph showing
pulmonary venous congestion (positive LR = 12.0; 95% CI, 6.8-21.0);
and (5) electrocardiogram showing atrial fibrillation (positive LR = 3.8;
95% CI, 1.7-8.8). The features that best decreased the probability of heart
failure were the absence of (1) past history of heart failure (negative LR = 0.45;
95% CI, 0.38-0.53); (2) the symptom of dyspnea on exertion (negative LR = 0.48;
95% CI, 0.35-0.67); (3) rales (negative LR = 0.51; 95% CI, 0.37-0.70);
(4) the chest radiograph showing cardiomegaly (negative LR = 0.33;
95% CI, 0.23-0.48); and (5) any electrocardiogram abnormality (negative LR = 0.64;
95% CI, 0.47-0.88). A low serum BNP proved to be the most useful test (serum
B-type natriuretic peptide <100 pg/mL; negative LR = 0.11; 95%
For dyspneic adult emergency department patients, a directed history,
physical examination, chest radiograph, and electrocardiography should be
performed. If the suspicion of heart failure remains, obtaining a serum BNP
level may be helpful, especially for excluding heart failure.