Mornos Cristian, Ruşinaru Dan, Ionac Adina, Petrescu Lucian, Cozma Dragoş, Pescariu Sorin, Drăgulescu Stefan Iosif
Cardiology Clinic, Institute of Cardiovascular Diseases, Timişoara, Romania.
Acta Cardiol. 2011 Oct;66(5):565-72. doi: 10.1080/ac.66.5.2131080.
Torsional and longitudinal deformations are essential components of left ventricular (LV) performance. A precise assessment of LV function must take into account both LV torsion (LVtor) and global longitudinal strain (LVE). We compared a new 2D-strain parameter, LVtor x LVE, with several other echocardiographic parameters, with respect to their strength of association with N-terminal pro-brain natriuretic peptide (NTproBNP) in patients with reduced LV ejection fraction (LVEF).
Echocardiography was performed simultaneously with NTproBNP determination in 78 consecutive patients with reduced LVEF (<50%) in sinus rhythm. Early diastolic transmitral velocity/early mitral annular diastolic velocity ratio (E/E') and systolic mitral annular velocity (S') were measured. LVtor was defined as the ratio between LV twist (LVtw) and LV end-diastolic longitudinal length. LVtw (net difference between rotation angles at base and apex) was obtained from parasternal apical and basal short-axis planes. LVE was obtained by averaging longitudinal peak systolic strain of all 17 LV-segments (from apical planes).
Log-transformed NTproBNP correlated significantly with LVE (r = 0.57, P < 0.001), myocardial performance index (r = 0.56, P < 0.001), systolic pulmonary artery pressure (r = 0.47, P < 0.001), E/E' (r = 0.41, P < 0.001), LVtor (r = -0.37, P = 0.001), E-velocity deceleration time (r = -0.37, P = 0.003), S' (r = -0.36, P = 0.002), LVtw (r = -0.34, P = 0.003), LVEF (r = -0.34, P = 0.003), E/A (A = late diastolic transmitral velocity, r = 0.30, P = 0.01) and E (r = 0.28, P = 0.03). LVtor x LVepsilon had the strongest correlation with log-NTproBNP (r = 0.70, P < 0.001). LVtor x LVepsilon was a better predictor of NTproBNP > 900 pg/ml (sensitivity = 82%, specificity = 84%) than other investigated parameters (each P < 0.05).
In patients with reduced LVEF, LVtor x LVE is a promising parameter that deserves research to establish its clinical meaning and prognostic value.
扭转和纵向变形是左心室（LV）功能的重要组成部分。对LV功能的精确评估必须同时考虑LV扭转（LVtor）和整体纵向应变（LVE）。我们比较了一种新的二维应变参数LVtor×LVE与其他几个超声心动图参数，就其与左心室射血分数（LVEF）降低患者的N末端脑钠肽前体（NTproBNP）的关联强度而言。
对78例连续的窦性心律LVEF降低（<50%）的患者同时进行超声心动图检查和NTproBNP测定。测量舒张早期二尖瓣血流速度/二尖瓣环舒张早期速度比值（E/E'）和二尖瓣环收缩期速度（S'）。LVtor定义为LV扭转（LVtw）与LV舒张末期纵向长度的比值。LVtw（心底和心尖旋转角度的净差值）从胸骨旁心尖和心底短轴平面获得。LVE通过平均所有17个LV节段（来自心尖平面）的纵向收缩期峰值应变获得。
经对数转换的NTproBNP与LVE（r = 0.57，P < 0.001）、心肌性能指数（r = 0.56，P < 0.001）、收缩期肺动脉压（r = 0.47，P < 0.001）、E/E'（r = 0.41，P < 0.001）、LVtor（r = -0.37，P = 0.001）、E波减速时间（r = -0.37，P = 0.003）、S'（r = -0.36，P = 0.002）、LVtw（r = -0.34，P = 0.003）、LVEF（r = -0.34，P = 0.003）、E/A（A = 舒张晚期二尖瓣血流速度，r = 0.30，P = 0.01）和E（r = 0.28，P = 0.03）显著相关。LVtor×LVepsilon与对数NTproBNP的相关性最强（r = 0.70，P < 0.001）。与其他研究参数相比，LVtor×LVepsilon对NTproBNP>900 pg/ml的预测更好（敏感性 = 82%，特异性 = 84%）（各P < 0.05）。
在LVEF降低的患者中，LVtor×LVE是一个有前景的参数，值得进行研究以确定其临床意义和预后价值。
