Methodist DeBakey Heart and Vascular Center, Houston, Texas, United States of America.
Department of Cardiology, Aalborg University Hospital, Aalborg, Denmark.
PLoS One. 2021 Feb 10;16(2):e0245934. doi: 10.1371/journal.pone.0245934. eCollection 2021.
Left atrial (LA) strain is associated with symptomatic status and atrial fibrillation in patients with hypertrophic cardiomyopathy (HCM). However, hemodynamic determinants of LA reservoir (LARS), conduit, and pump strains have not been examined and data are needed on the relation of LA strain with exercise tolerance in HCM.
Fifty HCM patients with echocardiographic and CMR imaging within 30 days were included. Left ventricular (LV) volumes, mass, EF, scar extent, extracellular volume fraction (ECV), and LA maximum volume were measured by CMR. Echo studies were analyzed for mitral inflow, pulmonary vein flow, mitral annulus tissue Doppler velocities, LV global longitudinal strain, and LA strain. Twenty six patients able and willing to exercise underwent cardiopulmonary stress testing for peak oxygen consumption (MVO2), and VE/VCO2 slope. Patients were followed for clinical events.
LARS was significantly associated with indices of LA systolic function, LV GLS, and LV filling pressures (P<0.05). Conduit strain was significantly associated with mitral annulus early diastolic velocity and ECV, whereas LA pump strain was determined by LA systolic function and indices of LV end diastolic pressure (all P<0.05). LARS and conduit strain were significantly higher in patients who achieved ≥80% of MVO2. LARS, conduit, and pump strains were significantly associated with atrial fibrillation (P<0.05).
LV structure, systolic and diastolic function, and LA systolic function determine the 3 components of LA strain. LA strain is associated with exercise tolerance and clinical events in patients with HCM.
左心房（LA）应变与肥厚型心肌病（HCM）患者的症状状态和心房颤动相关。然而，LA 储备（LARS）、输送和泵应变的血液动力学决定因素尚未被检查，并且需要有关 LA 应变与 HCM 患者运动耐量的关系的数据。
在 30 天内接受超声心动图和 CMR 成像的 50 名 HCM 患者被纳入研究。CMR 测量左心室（LV）容积、质量、EF、疤痕范围、细胞外容积分数（ECV）和 LA 最大容积。超声心动图分析二尖瓣流入、肺静脉血流、二尖瓣环组织多普勒速度、LV 整体纵向应变和 LA 应变。26 名能够且愿意进行运动的患者接受心肺压力测试以测量峰值耗氧量（MVO2）和 VE/VCO2 斜率。对患者进行临床事件随访。
LARS 与 LA 收缩功能、LV GLS 和 LV 充盈压的指标显著相关（P<0.05）。输送应变与二尖瓣环早期舒张速度和 ECV 显著相关，而 LA 泵应变由 LA 收缩功能和 LV 舒张末期压力的指标决定（均 P<0.05）。达到 MVO2≥80%的患者的 LARS 和输送应变显著更高。LARS、输送和泵应变与心房颤动显著相关（P<0.05）。
LV 结构、收缩和舒张功能以及 LA 收缩功能决定了 LA 应变的 3 个组成部分。LA 应变与 HCM 患者的运动耐量和临床事件相关。
