Department of Cardiology, RWTH Aachen University, Aachen, Germany.
JACC Cardiovasc Imaging. 2011 Apr;4(4):366-74. doi: 10.1016/j.jcmg.2011.01.010.
This study sought to analyze the effectiveness of cardiac resynchronization therapy (CRT) related to the viability in the segment of left ventricular (LV) lead position defined by myocardial deformation imaging.
Echocardiographic myocardial deformation analysis allows determination of LV lead position as well as extent of myocardial viability.
Myocardial deformation imaging based on tracking of acoustic markers within 2-dimensional echo images (GE Ultrasound, GE Healthcare, Horton, Norway) was performed in 65 heart failure patients (54 ± 6 years of age, 41 men) before and 12 months after CRT implantation. In a 16-segment model, the LV lead position was defined based on the segmental strain curve with earliest peak strain, whereas the CRT system was programmed to pure LV pacing. Nonviability of a segment (transmural scar formation) was assumed if the peak systolic circumferential strain was >-11.1%.
In 47 patients, the LV lead was placed in a viable segment, and in 18 patients, it was placed in a nonviable segment. At 12-month follow-up there was greater decrease of LV end-diastolic volumes (58 ± 13 ml vs. 44 ± 12 ml, p = 0.0388) and greater increase of LV ejection fraction (11 ± 4% vs. 5 ± 4%, p = 0.0343) and peak oxygen consumption (2.5 ± 0.9 ml/kg/min vs. 1.7 ± 1.1 ml/kg/min, p = 0.0465) in the viable compared with the nonviable group. The change in LV ejection fraction and the reduction in LV end-diastolic volumes at follow-up correlated to an increasing peak systolic circumferential strain in the segment of the LV pacing lead (r = 0.61, p = 0.0274 and r = 0.64, p = 0.0412, respectively). Considering only patients with ischemic heart disease, differences between viable and nonviable LV lead position group were even greater.
Preserved viability in the segment of the CRT LV lead position results in greater LV reverse remodeling and functional benefit at 12-month follow-up. Deformation imaging allows analysis of viability in the LV lead segment.
本研究旨在分析心脏再同步治疗（CRT）与左心室（LV）起搏导线节段心肌存活之间的相关性。
超声心动图心肌应变分析可确定 LV 起搏导线位置和心肌存活范围。
对 65 例心力衰竭患者（年龄 54±6 岁，男 41 例）进行二维超声心动图（GE 超声，GE 医疗，挪威 Horton）声学标记跟踪心肌应变成像，于 CRT 植入术前和术后 12 个月进行。在 16 节段模型中，根据最早峰值应变的节段应变曲线来定义 LV 起搏导线位置，而 CRT 系统被编程为单纯 LV 起搏。如果节段性收缩期圆周应变＞-11.1%，则假定该节段无活力（透壁瘢痕形成）。
47 例患者的 LV 起搏导线置于有活力的节段，18 例患者的 LV 起搏导线置于无活力的节段。在 12 个月的随访中，LV 舒张末期容积的下降更为明显（58±13 ml 比 44±12 ml，p=0.0388），LV 射血分数的增加更为明显（11±4%比 5±4%，p=0.0343），峰值耗氧量的增加更为明显（2.5±0.9 ml/kg/min 比 1.7±1.1 ml/kg/min，p=0.0465），有活力组与无活力组比较差异均有统计学意义。LV 射血分数的变化和随访时 LV 舒张末期容积的减少与 LV 起搏导线节段的收缩期圆周应变峰值呈正相关（r=0.61，p=0.0274 和 r=0.64，p=0.0412）。仅考虑缺血性心脏病患者，有活力与无活力 LV 起搏导线位置组之间的差异更大。
CRT 左心室起搏导线节段保留的活力可导致 12 个月随访时 LV 逆重构和功能获益更大。应变成像可分析 LV 起搏导线节段的活力。
