Cardiac ultrasound helps for differentiating the causes of acute dyspnea with available B-type natriuretic peptide tests

IntroductionThe aim of this study was to evaluate the role of cardiac ultrasound in diagnosing acute heart failure (AHF) in patients with acute dyspnea with available plasma B-type natriuretic peptide (BNP) level.MethodsPatients with acute dyspnea presenting to the emergency department (ED) of a tertiary medical center were prospectively enrolled. The enrolled 84 patients received both BNP tests and cardiac ultrasound studies and were classified into AHF and non–heart failure groups.ResultsPlasma BNP levels were higher in the AHF group (1236 ± 1123 vs 354 ± 410 pg/mL; P < .001). The AHF group had larger left ventricular end-diastolic dimension (LVEDD; 32 ± 7 vs 27 ± 4 mm/m2; P < .001) and worse left ventricular ejection fraction (52% ± 18% vs 64% ± 15%; P = .003). Multiple logistic regression analysis showed that both BNP levels more than 100 pg/mL and LVEDD were independent predictors for AHF. In patients with plasma BNP levels within gray zone of 100 to 500 pg/mL, LVEDD was larger in the AHF group than that in the non–heart failure group (29 ± 4 vs 26 ± 4 mm/m2; P = .044).ConclusionBoth LVEDD by cardiac ultrasound and BNP levels can help emergency physicians independently diagnose AHF in the ED. In patients with plasma BNP levels within 100 to 500 pg/mL, cardiac ultrasound can help differentiate heart failure or not.