左心房負荷の弁膜疾患における左心房ストレイン：逆流症と狭窄症の比較分析

Left atrial (LA) strain analysis is an emerging echocardiographic technique for assessing LA function. This study aimed to compare LA strain parameters in patients with mitral stenosis (MS) and mitral regurgitation (MR) to identify discriminators between these conditions.

This cross-sectional study included 44 patients with moderate-to-severe MR and 44 patients with severe-to-very severe MS, all with normal left ventricular ejection fraction. Patients with left ventricular systolic dysfunction, ischemic mitral regurgitation, or atrial fibrillation were excluded. Clinical data were collected, and LA strain analysis was performed offline using EchoPAC software. The study analyzed LA reservoir, conduit, and contractile strain components.LAstrainSR, LAstrainCD and LAstrainCT were derived and analyzed for their diagnostic performance. Data were analyzed using SPSS version 26.0, with one-way ANOVA used to compare LA strain parameters between groups.

LAstrainCD demonstrated the highest diagnostic accuracy (81.8%) for differentiating MS from MR, making it the most reliable strain parameter. LAstrainCT showed the best performance for assessing MR severity, with a moderate accuracy of 61.5%.

This study elucidates the distinct impacts of mitral stenosis and regurgitation on left atrial function, as reflected by LA strain parameters. LAstrainCD emerges as a key discriminator between these conditions, highlighting differences in atrial remodeling due to pressure and volume overload. Furthermore, LAstrainCT's correlation with MR severity enhances our understanding of atrial adaptation to regurgitant volume. These findings advance the knowledge of mitral valve disease pathophysiology, providing a foundation for improved diagnostic and therapeutic strategies.