CHU Rennes, Service de Cardiologie et Maladies Vasculaires et CIC-IT 1414, 2 Rue Henri Le Guilloux, CHU Pontchaillou, Rennes, France.
Université de Rennes 1, LTSI, campus Beaulieu, Rennes, France.
Eur Heart J Cardiovasc Imaging. 2018 Dec 1;19(12):1372-1379. doi: 10.1093/ehjci/jey024.
The area of left ventricular (LV) pressure-strain loop (PSL) is used as an index of regional myocardial work. The purpose of the present work is to compare the main segmental PSL markers and the derived global work indices, when they are calculated using an estimated pressure signal or an observed pressure signal.
In nine patients implanted with a bi-ventricular pace-maker (CRT), LV pressure was invasively measured in five conditions: CRT-off, LV-pacing, right ventricular-pacing and two different CRT-pacing. For each condition, systolic blood pressure was measured by brachial artery cuff-pressure and transthoracic echocardiography loops were recorded simultaneously. The error and relative root mean square error (rRMSE) between measured and estimated pressure were calculated for each patient and each configuration. Correlation coefficient (R2) and Bland-Altman (BA) analysis were performed for PSL area and work indices. A total of 43 different haemodynamic conditions were compared (774 segmental PSL). The global rRMSE between estimated and measured LV-pressure was 12.3 mmHg. The estimated and measured segmental LV-PSL were strongly correlated, with an R2 of 0.98. BA analysis shows that the mean bias for the estimation of segmental LV-PSL area is 86.0 mmHg.%. A significant bias effect with linearly increasing error with pressure values is observed. R2 ≥ 0.88 and a mean bias in BA analysis ≤41.4 mmHg.% was observed for the estimation of global myocardial work indices.
The non-invasive estimation for LV pressure-strain loop area and the global myocardial work indices obtained from LV-PSL strongly correlates with invasive measurements.
左心室（LV）压力-应变环（PSL）的面积被用作区域心肌做功的指标。本研究的目的是比较使用估计压力信号或观察压力信号计算时主要节段 PSL 标志物和衍生的整体工作指标。
在 9 名植入双心室起搏器（CRT）的患者中，在 5 种情况下经皮测量 LV 压力：CRT 关闭、LV 起搏、右心室起搏和两种不同的 CRT 起搏。对于每种情况，通过肱动脉袖带压力测量收缩压，并同时记录经胸超声心动图环。为每位患者和每种配置计算测量和估计压力之间的误差和相对均方根误差（rRMSE）。对 PSL 面积和工作指标进行相关系数（R2）和 Bland-Altman（BA）分析。总共比较了 43 种不同的血流动力学条件（774 个节段 PSL）。估计和测量的 LV 压力之间的整体 rRMSE 为 12.3mmHg。估计和测量的节段性 LV-PSL 具有很强的相关性，R2 为 0.98。BA 分析显示，节段性 LV-PSL 面积估计的平均偏差为 86.0mmHg。观察到线性增加压力值的误差的显著偏差效应。对于整体心肌工作指数的估计，R2≥0.88，BA 分析中的平均偏差≤41.4mmHg。
LV 压力-应变环面积的非侵入性估计和从 LV-PSL 获得的整体心肌工作指数与侵入性测量具有很强的相关性。
