Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong kong, Hong Kong, China.
Int J Cardiol. 2012 Sep 20;160(1):31-5. doi: 10.1016/j.ijcard.2011.03.018. Epub 2011 Apr 8.
The effects of right ventricular (RV) pacing on left ventricular (LV) diastolic function are unknown. This study aimed to test the hypothesis that right ventricular (RV) pacing is associated with LV diastolic dysfunction and impairment of LV torsion in children and young adults with congenital heart block.
Eighteen patients aged 20 ± 7 years and 12 healthy controls aged 19 ± 7 years were studied. Transmitral and mitral annular diastolic velocities and global longitudinal diastolic strain rate were determined and compared between the 2 groups. Parameters of LV torsion including peak systolic basal and apical rotations, and systolic twisting and diastolic untwisting velocities were further determined by speckle tracking echocardiography. In 12 patients, these parameters were compared before and after interruption of RV pacing.
Compared with controls, patients had significantly lower mitral early diastolic annular velocity (p=0.007), LV global diastolic strain rate (p<0.001), basal (p<0.001) and apical (p=0.002) rotations, peak systolic torsion (p<0.001), and peak systolic twisting velocities (p=0.009). In patients, the peak diastolic untwisting velocity correlated with peak systolic torsion (r=0.64, p=0.004) and peak systolic twisting velocity (r=0.74, p<0.001). No significant improvement in LV diastolic function or torsion was observed during pacing interruption (all p>0.05).
Right ventricular pacing in childhood is associated with LV diastolic dysfunction and impaired LV torsion, which do not improve with pacing interruption.
右心室（RV）起搏对左心室（LV）舒张功能的影响尚不清楚。本研究旨在检验以下假设，即右心室（RV）起搏与先天性心脏传导阻滞患儿和年轻成人的 LV 舒张功能障碍和 LV 扭转受损有关。
研究了 18 名年龄为 20 ± 7 岁的患者和 12 名年龄为 19 ± 7 岁的健康对照者。在两组之间测定并比较了经二尖瓣和二尖瓣环舒张速度以及整体纵向舒张应变率。通过斑点追踪超声心动图进一步确定了包括收缩期基底和心尖旋转、收缩期扭转和舒张期解旋速度在内的 LV 扭转参数。在 12 名患者中，比较了 RV 起搏中断前后这些参数的变化。
与对照组相比，患者的二尖瓣早期舒张环速度明显降低（p=0.007），LV 整体舒张应变率明显降低（p<0.001），基底（p<0.001）和心尖（p=0.002）旋转、收缩期峰值扭转（p<0.001）和收缩期峰值扭转速度（p=0.009）明显降低。在患者中，峰值舒张解旋速度与收缩期峰值扭转（r=0.64，p=0.004）和收缩期峰值扭转速度（r=0.74，p<0.001）相关。起搏中断时，LV 舒张功能或扭转均无明显改善（均 p>0.05）。
儿童时期的右心室起搏与 LV 舒张功能障碍和 LV 扭转受损有关，起搏中断并不能改善这些情况。
