Ozaydin Mehmet, Tada Hiroshi, Chugh Aman, Scharf Christoph, Lai Steve W K, Pelosi Frank, Knight Bradley P, Morady Fred, Oral Hakan
Division of Cardiology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA.
Pacing Clin Electrophysiol. 2003 Sep;26(9):1859-63. doi: 10.1046/j.1460-9592.2003.t01-1-00281.x.
Large atrial electrogram amplitudes recorded in the cavotricuspid isthmus (CTI) may reflect thick atrial musculature. For this reason, in patients with atrial flutter, the efficacy of an application of conventional radiofrequency energy may be related to the amplitude of the local atrial electrogram. In 100 consecutive patients (mean age 59 +/- 13 years) with atrial flutter, contiguous applications of radiofrequency energy were delivered in the CTI. The criterion for complete CTI block was the presence of widely split double potentials (>110 ms) along the entire ablation line during pacing from the coronary sinus and posterolateral right atrium. The atrial electrogram amplitude was measured before and after applications of radiofrequency energy at sites of gaps in the ablation line. Complete CTI block was achieved in 90 (90%) of the 100 patients. The mean atrial electrogram amplitudes at gap sites where an application of radiofrequency energy did and did not result in complete block were 0.36 +/- 0.42 and 0.67 +/- 0.62 mV, respectively (P < 0.01). The positive and negative predictive values (for complete block) of a >/=50% decrease in electrogram amplitude after an application of radiofrequency energy were 100% and 35%, respectively. The mean atrial electrogram amplitude is larger at CTI sites where complete isthmus block cannot be achieved with conventional radiofrequency energy. The efficacy of conventional radiofrequency ablation may be improved by identifying areas in the CTI where the voltage is relatively low.
在腔静脉三尖瓣峡部（CTI）记录到的大心房电图振幅可能反映心房肌增厚。因此，在心房扑动患者中，传统射频能量应用的疗效可能与局部心房电图的振幅有关。在100例连续的心房扑动患者（平均年龄59±13岁）中，在CTI处连续应用射频能量。完全CTI阻滞的标准是在从冠状窦和右心房后外侧起搏时，沿整个消融线存在宽分离的双电位（>110毫秒）。在消融线间隙部位应用射频能量前后测量心房电图振幅。100例患者中有90例（90%）实现了完全CTI阻滞。射频能量应用导致和未导致完全阻滞的间隙部位的平均心房电图振幅分别为0.36±0.42和0.67±0.62毫伏（P<0.01）。射频能量应用后电图振幅下降≥50%（针对完全阻滞）的阳性和阴性预测值分别为100%和35%。在传统射频能量无法实现完全峡部阻滞的CTI部位，平均心房电图振幅更大。通过识别CTI中电压相对较低的区域，可能会提高传统射频消融的疗效。
