Van Gelder Berry M, Bracke Frank A
Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands.
Pacing Clin Electrophysiol. 2008 Dec;31(12):1519-21. doi: 10.1111/j.1540-8159.2008.01221.x.
In cardiac resynchronization therapy (CRT), the morphology of the QRS complex plays an important role in the determination of the pacing site and effectiveness of stimulation.
Review of the electrocardiograms (ECGs) of 737 patients with a CRT device showed a negative QRS complex in lead I during right ventricular (RV) pacing and a positive QRS complex during left ventricular (LV) pacing in four patients. The RV lead was positioned in the high RV septum and the coronary sinus leads in a posterior or postero-lateral basal level. Reversed ECG lead or pacemaker lead connection, anodal RV stimulation, and scar tissue-related depolarization abnormalities were excluded as possible causes.
Pacing from the high RV septum may rarely lead to a negative QRS complex and basal positions of the LV lead to a positive QRS complex in lead I during LV pacing. The lead I paradox becomes obvious when both phenomena, that are not interrelated, are present in the same patient.
在心脏再同步治疗（CRT）中，QRS波群形态在确定起搏部位和刺激效果方面起着重要作用。
回顾737例植入CRT设备患者的心电图（ECG），发现4例患者右心室（RV）起搏时I导联QRS波群为负向，左心室（LV）起搏时I导联QRS波群为正向。RV电极位于高位RV间隔，冠状窦电极位于后或后外侧基底部。排除了ECG导联或起搏器电极连接反转、阳极RV刺激以及瘢痕组织相关的去极化异常等可能原因。
高位RV间隔起搏可能很少导致I导联QRS波群为负向，而LV电极位于基底部时，LV起搏时I导联QRS波群为正向。当同一患者同时出现这两种不相关的现象时，I导联悖论变得明显。
