Clinical relevance of echocardiography in acute severe dyspnea.

Background: The aim of this study was to assess the most relevant echocardiographic parameter for the clinical diagnosis of acute dyspnea due to left-heart dysfunction.
Methods: Transthoracic echocardiography was performed in 88 patients in sinus rhythm admitted for respiratory distress. Two experts determined the cause of dyspnea as cardiogenic (26 patients) or noncardiogenic (62 patients).
Results: The feasibility was 100% for the E/A ratio and the E/E deceleration time (EDT) ratio but 97%, 89%, and 85% for the E/Ea ratio, left ventricular ejection fraction (LVEF), and the E/propagation velocity (Vp) ratio, respectively. The area under the receiver operating characteristic curve for E/EDT (0.947 +/- 0.035) was statistically significantly greater than that for E/A (0.753 +/- 0.068) (P = .004). The areas under the curves for all other parameters were not statistically significantly different. In the subpopulation of patients with LVEFs > 45%, the area under the curve for LVEF was significantly smaller than those for E/Ea, E/EDT, and E/Vp.
Conclusion: E/EDT, E/Ea, and E/Vp appear equally useful to distinguish acute dyspnea due to left-heart dysfunction from that of pulmonary origin. However, E/EDT and E/Ea can be considered the best indices with regard to feasibility.