Castellanos A, Agha A S, Mendoza I J, Sung R J
Br Heart J. 1977 Jul;39(7):726-32. doi: 10.1136/hrt.39.7.726.
Invasive electrophysiological studies were performed in 2 symptomatic patients with recurrent arrhythmias in which impulse formation presumably occured within atrioventricular nodal bypass tracts. Case 1 had ectopic beats arising within, or close to, the upper end of a left-sided atrioventricular nodal bypass tract of the type described by Brechenmacher. In addition, this conduction was 'concealed' during sinus rhythm and right atrial pacing because the relatively prolonged right-to-left atrial conduction time allowed right atrial impulses to reach the His bundle via the atrioventricular node before they could do so through the atrioventricular nodal bypass tract. Case 2 had ectopic beats arising in a right-sided atrioventricular nodal bypass tract which did not conduct in either forward or retrograde directions, its presence being detected only when initiating impulses. However, it could not be determined whether this tract was an 'abnormal' atrio-His connection or a 'normal' transitional (atrio-atrioventricular nodal) tract. Though intracardiac studies complement body surface recordings, they should be interpreted with knowledge of their inherent limitations.
对2例有复发性心律失常症状的患者进行了有创电生理研究，推测冲动形成于房室结旁道内。病例1的异位搏动起源于Brechenmacher描述的左侧房室结旁道上端或其附近。此外，在窦性心律和右心房起搏期间，这种传导是“隐匿性”的，因为相对延长的右向左心房传导时间使右心房冲动能够先通过房室结到达希氏束，再通过房室结旁道。病例2的异位搏动起源于右侧房室结旁道，该旁道无前向或逆向传导，仅在引发冲动时才被检测到。然而，无法确定该旁道是“异常”的房-希氏连接还是“正常”的过渡性（房-房室结）通道。虽然心内研究补充了体表记录，但对其解释应了解其固有的局限性。
