Hayashi Shuji, Yamada Hirotsugu, Bando Mika, Saijo Yoshihito, Nishio Susumu, Hirata Yukina, Klein Allan L, Sata Masataka
Ultrasound Examination Center, Tokushima University Hospital, Tokushima, Japan.
Department of Cardiovascular Medicine, Tokushima University Hospital, Tokushima, Japan.
Echocardiography. 2015 Aug;32(8):1241-9. doi: 10.1111/echo.12834. Epub 2014 Nov 3.
Left atrial (LA) strain analysis using speckle tracking echocardiography is useful for assessing LA function. However, there is no established procedure for this method. Most investigators have determined the electrocardiographic R-wave peak as the starting point for LA strain analysis. To test our hypothesis that P-wave onset should be used as the starting point, we measured LA strain using 2 different starting points and compared the strain values with the corresponding LA volume indices obtained by three-dimensional (3D) echocardiography.
We enrolled 78 subjects (61 ± 17 years, 25 males) with and without various cardiac diseases in this study and assessed global longitudinal LA strain by two-dimensional speckle tracking strain echocardiography using EchoPac software. We used either R-wave peak or P-wave onset as the starting point for determining LA strains during the reservoir (Rres, Pres), conduit (Rcon, Pcon), and booster pump (Rpump, Ppump) phases. We determined the maximum, minimum, and preatrial contraction LA volumes, and calculated the LA total, passive, and active emptying fractions using 3D echocardiography.
The correlation between Pres and LA total emptying fraction was better than the correlation between Rres and LA total emptying fraction (r = 0.458 vs. 0.308, P = 0.026). Pcon and Ppump exhibited better correlation with the corresponding 3D echocardiographic parameters than Rcon (r = 0.560 vs. 0.479, P = 0.133) and Rpump (r = 0.577 vs. 0.345, P = 0.003), respectively.
LA strain in any phase should be analyzed using P-wave onset as the starting point rather than R-wave peak.
使用斑点追踪超声心动图进行左心房（LA）应变分析有助于评估LA功能。然而，该方法尚无既定程序。大多数研究者将心电图R波峰值作为LA应变分析的起始点。为了验证我们关于应将P波起始点用作起始点的假设，我们使用2个不同的起始点测量了LA应变，并将应变值与通过三维（3D）超声心动图获得的相应LA容积指数进行比较。
我们纳入了78名患有和未患有各种心脏病的受试者（61±17岁，25名男性），并使用EchoPac软件通过二维斑点追踪应变超声心动图评估整体纵向LA应变。在储存期（Rres，Pres）、管道期（Rcon，Pcon）和增压泵期（Rpump，Ppump）确定LA应变时，我们使用R波峰值或P波起始点作为起始点。我们确定了最大、最小和心房收缩前LA容积，并使用3D超声心动图计算了LA总排空分数、被动排空分数和主动排空分数。
Pres与LA总排空分数之间的相关性优于Rres与LA总排空分数之间的相关性（r = 0.458对0.308，P = 0.026）。与Rcon（r = 0.560对0.479，P = 0.133）和Rpump（r = 0.577对0.345，P = 0.003）相比，Pcon和Ppump分别与相应的3D超声心动图参数表现出更好的相关性。
任何阶段的LA应变均应以P波起始点而非R波峰值作为起始点进行分析。
