Tanoiri T, Nomoto J, Mogi J, Yoshitake N, Abe K, Saito H, Okamura T
4th Department of Internal Medicine, Jikei University Medical School, Tokyo, Japan.
Jpn Circ J. 1995 Dec;59(12):775-85. doi: 10.1253/jcj.59.775.
Rapid pacing from the high right atrium was performed in 7 patients with atrial flutter in whom potentials with multicomponent high-frequency deflections were recorded at the high right atrium to examine the origin of these potentials during transient entrainment in atrial flutter. In all of the patients with relatively slow rapid pacing, the potentials were captured orthodromically through the atrial flutter reentry circuit with a long conduction time. With more rapid pacing, the potentials were split into 2 associated components: P1 and P2. P1 was captured antidromically with a short conduction time whereas P2 was captured persistently in an orthodromic direction through the reentry circuit with a progressively long conduction time. In 3 of the 7 patients, atrial flutter was converted into another atrial flutter by rapid pacing. During this other atrial flutter, the potentials at the high right atrium were split from the beginning to form double potentials: D1 and D2. During rapid pacing, D1 and D2 were fused, and D1 was captured antidromically whereas D2 was captured orthodromically through the reentry circuit. In sinus rhythm, the potentials at the high right atrium formed fractionated potentials. These findings suggest that 1) fractionated potentials may represent 2 atrial regions with different conductivity properties, 2) fractionated potentials may be able to change into double potentials, and 3) double potentials may be attributable to their conductivity properties rather than refractoriness.
对7例心房扑动患者进行了高位右心房快速起搏，这些患者在高位右心房记录到具有多成分高频偏转的电位，以研究心房扑动时短暂超速抑制期间这些电位的起源。在所有相对缓慢的快速起搏患者中，电位通过传导时间较长的心房扑动折返环以顺向方式被夺获。随着起搏速度加快，电位分裂为两个相关成分：P1和P2。P1以较短的传导时间被逆向夺获，而P2则通过折返环以逐渐延长的传导时间持续以顺向方式被夺获。在7例患者中的3例中，快速起搏使心房扑动转变为另一种心房扑动。在这种另一种心房扑动期间，高位右心房的电位从一开始就分裂形成双电位：D1和D2。在快速起搏期间，D1和D2融合，D1被逆向夺获，而D2通过折返环以顺向方式被夺获。在窦性心律时，高位右心房的电位形成碎裂电位。这些发现提示：1）碎裂电位可能代表具有不同传导特性的两个心房区域；2）碎裂电位可能能够转变为双电位；3）双电位可能归因于其传导特性而非不应期。
