Huang Jin Long, Tai Ching-Tai, Lin Yenn-Jiang, Huang Bien-Hsien, Lee Kun-Tai, Higa Satoshi, Yuniadi Yoga, Chen Yi-Jen, Chang Shih-Lin, Lo Li-Wei, Wongcharoen Wanwarang, Ting Chih-Tai, Chen Shih-Ann
Institute of Clinical Medicine and Cardiovascular Research Institute, National Yang-Ming University, Taipei, Taiwan.
J Am Coll Cardiol. 2006 Aug 1;48(3):492-8. doi: 10.1016/j.jacc.2006.03.045. Epub 2006 Jul 12.
The purpose of this study was to investigate the relationship between the abnormal substrate and peak negative voltage (PNV) in the right atrium (RA) with atypical flutter.
The impact of a local abnormally low voltage electrogram on the local activation pattern and velocity of atrial flutter (AFL) remains unclear.
Twelve patients with clinically documented AFL were included to undergo noncontact mapping of the RA. The atrial substrate was characterized by the: 1) activation mapping; 2) high-density voltage mapping; and 3) conduction velocity along the flutter re-entrant circuit. The normalized PNV (i.e., the relative ratio to the maximal PNV) in each virtual electrode recording was used to produce the voltage maps of the entire chamber. The protected isthmus was bordered by low voltage zones.
Atypical AFL of the RA was induced by atrial pacing in 12 patients, including 10 upper loop re-entry and 2 RA free wall re-entry flutter. These protected isthmuses were located near the crista terminalis. The mean width of the protected isthmus was 1.7 +/- 0.3 cm and mean voltage at the isthmus was -0.91 +/- 0.39 mV. The conduction velocities within these paths were significantly slower than outside the path (0.30 +/- 0.18 m/s vs. 1.14 +/- 0.41 m/s, respectively; p = 0.004). The ratiometric PNV of 37.6% of the maximal PNV had the best cut-off value to predict slow conduction, with a high sensitivity (92.3%) and specificity (85.7%).
Characterization of the RA substrate in terms of the unipolar PNV is an effective predictor of the slow conduction path within the critical isthmus of the re-entrant circuit.
本研究旨在探讨非典型心房扑动时右心房（RA）异常基质与负向峰值电压（PNV）之间的关系。
局部异常低电压心电图对心房扑动（AFL）的局部激动模式和速度的影响仍不清楚。
纳入12例临床确诊为AFL的患者，对其右心房进行非接触式标测。心房基质通过以下方式进行特征化：1）激动标测；2）高密度电压标测；3）沿扑动折返环的传导速度。每个虚拟电极记录中的归一化PNV（即相对于最大PNV的相对比值）用于生成整个腔室的电压图。受保护峡部由低电压区界定。
12例患者通过心房起搏诱发了右心房非典型AFL，其中包括10例上环路折返和2例右心房游离壁折返扑动。这些受保护峡部位于界嵴附近。受保护峡部的平均宽度为1.7±0.3 cm，峡部的平均电压为-0.91±0.39 mV。这些路径内的传导速度明显慢于路径外（分别为0.30±0.18 m/s和1.14±0.41 m/s；p = 0.004）。最大PNV的37.6%的比例性PNV具有预测缓慢传导的最佳截断值，敏感性高（92.3%），特异性高（85.7%）。
根据单极PNV对右心房基质进行特征化是折返环关键峡部内缓慢传导路径的有效预测指标。
