Torsion of the left ventricle during pacing with MRI tagging
Torsion of the left ventricle during pacing with MRI tagging
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DOI：
10.1081/jcmr-120025227
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发表时间：
2003-01-01
影响因子：
6.4
通讯作者：
McVeigh, ER
中科院分区：
文献类型：
--
作者：
Sorger, JM;Wyman, BT;McVeigh, ER
在整个心脏周期内评估不同起搏方案对左室扭转的影响。收缩期和舒张期的一系列磁共振成像（MRI）扫描相结合，并用于计算犬模型的左室扭转。心室起搏引起的非同步激活干扰了左室扭转的时间演变。在三种不同的方案下研究左心室扭转：1)右心房起搏，2)右心室起搏，3)右心室心尖和左室底同时起搏。扭转的时间演变是由标记的MRI确定的，并在心脏周期内进行评估。心房起搏心脏的最大旋转度为11.1度（+/-3.5度），而右心室起搏心脏和双心室起搏心脏的最大旋转度分别为6.1度（+/-1.7度）和6.1度（+/-0.7度）。虽然双室起搏增加了收缩的同步性，但它明显改变了左室扭转的模式。从这些实验我们已经表明，测量扭转是一个非常敏感的指标，异位激励的存在。
The effects of different pacing protocols on left ventricular (LV) torsion were evaluated over the full cardiac cycle. A systolic and diastolic series of magnetic resonance imaging (MRI) scans were combined and used to calculate the torsion of the LV in a canine model. The asynchronous activation resulting from ventricular pacing interferes with the temporal evolution of LV torsion. The torsion of the left ventricle was investigated under three different protocols: 1) right atrial pacing, 2) right ventricular pacing, and 3) simultaneous pacing from the right ventricular apex and LV base. The temporal evolution of torsion was determined from tagged MRI and evaluated over the cardiac cycle. The peak rotation for the atrially paced hearts was 11.1degrees (+/-3.5degrees) compared to 6.1degrees (+/-1.7degrees) and 6.1degrees (+/-0.7degrees) for those hearts paced from the right ventricle and from both ventricles, respectively. While biventricular pacing increases the synchrony of contraction, it significantly alters the pattern of LV torsion. From these experiments we have shown that measuring torsion is an extremely sensitive indicator of the existence of ectopic excitation.