RESUMO
BACKGROUND: The analysis of left atrial (LA) function can add important information to the understanding of cardiovascular diseases. Therefore, to assess its functioning the use of volumetric measurements is adopted. The maximum LA volume is the most echocardiography parameter used, however some studies demonstrated that minimum LA volume is better to correlate with atrial dysfunction. PURPOSE: The purpose of this study was compare the accuracy of the phasic volumes of the left atrium in determining LA dysfunction identified by the two-dimensional strain. METHODS: This observational, cross-sectional study admitted 109 participants with diagnosis of acute coronary syndrome non-ST-segment elevation. The exams were performed within 72 hours of admission. LA volume was defined by the mean of measurements performed in the four and two-chamber apical windows using Simpson's method. The phasic volumes of the left atrium were measured using an electrocardiogram synchronized with the device. Reservoir LA strain less than 21% was the cut off to LA dysfunction. RESULTS: The phasic LA volume variables analyzed were maximal (LAVMAX), minimal (LAVMIN) and before atrial contraction (LAVBAC) volume, and each variable indexed for body surface (LAVIMAX, LAVIMIN and LAVIBAC). Therefore, a Roc curve was generated for each volume variable to assess which would be more accurate in predicting left atrial dysfunction. The Youden index was used to determine the cutoff point for each one of them. The areas under the Roc curves were: 0.83 (LAVIMIN), 0.81 (LAVMIN), 0.78 (LAVBAC), 0.76 (LAVIMAX), 0.74 (LAVIBAC) and 0.71 (LAVMAX). CONCLUSION: This study concluded that phasic volumes were good determinants of left atrial dysfunction identified by 2D strain. The minimum left atrial volume was the better correlate with left atrial dysfunction.
