Alboni P, Pedroni P, Malacarne C, Filippi L, De Lorenzi E, Masoni A
G Ital Cardiol. 1981;11(12):1871-82.
Recently there have been proposed electrophysiologic criteria for the diagnosis of a concealed atrio-His bypass tract in patients with paroxysmal supraventricular tachycardia (PST). In order to verify the reliability of the proposed criteria--among the patients we studied for PST without ventricular preexcitation and in whom retrograde His bundle activation was recorded--we have chosen those with normal anterograde A-V conduction, with constant (or minimal increases) V-A interval during ventricular pacing and with short (less than 50 msec) and constant H2-A2 interval during ventricular premature stimulation. We encountered 15 patients with these electrophysiologic characteristics (37-73 years). H2-A2 interval (measured from the end of the His bundle deflection to the earliest atrial activity) ranged 20-45 msec (mean: 33 msec). The prolongation of S2-A2 interval observed in all patients was always within the S2-H2 tract. The retrograde effective refractory period of the A-V nodal region was always short, but not evaluable in any of the patients since it was shorter than that of ventricular myocardium (14 cases) or of His-Purkinje system (1 case). The S1-H2 interval was measured to evaluate whether during ventricular premature stimulation the retrograde His bundle activation was in fact anticipated. In 14 out of 15 patients this interval varied within a very narrow range: 0-20 msec. For this reason we believe that the differential diagnosis between a concealed atrio-His bypass and an accelerated retrograde A-V conduction can only be made if during electrophysiologic study a tachycardia is induced; in such case the detection of an H-Ae interval identical to H2A2, together with a normal retrograde atrial activation, is indicative of a bypass of the A-V node. A concealed atrio-His bypass tract must be differentiated also by a concealed septal Kent bundle; also in this case we believe that the detection of an H-Ae interval identical to H2-A2 indicates the former type of bypass. We conclude that a concealed atrio-His bypass can be diagnosed only if, besides the electrophysiologic criteria proposed by other authors, there is an H-Ae interval the same as H2A2.
最近有人提出了阵发性室上性心动过速（PST）患者隐匿性房室旁路的电生理诊断标准。为了验证所提出标准的可靠性——在我们研究的无室性预激且记录到逆行希氏束激动的PST患者中——我们选择了那些具有正常前传房室传导、心室起搏时V-A间期恒定（或最小增加）以及室性早搏刺激时H2-A2间期短（小于50毫秒）且恒定的患者。我们遇到了15例具有这些电生理特征的患者（年龄37 - 73岁）。H2-A2间期（从希氏束波结束到最早心房活动测量）范围为20 - 45毫秒（平均：33毫秒）。所有患者中观察到的S2-A2间期延长始终在S2-H2径路内。房室结区域的逆行有效不应期总是很短，但由于比心室肌（14例）或希氏-浦肯野系统（1例）短，所以在任何患者中均无法评估。测量S1-H2间期以评估室性早搏刺激时逆行希氏束激动是否确实提前。15例患者中有14例该间期在非常窄的范围内变化：0 - 20毫秒。因此，我们认为只有在电生理研究中诱发心动过速时，才能对隐匿性房室旁路与加速性逆行房室传导进行鉴别诊断；在这种情况下，检测到与H2A2相同的H-Ae间期以及正常的逆行心房激动，提示房室结旁路。隐匿性房室旁路还必须与隐匿性间隔肯特束相鉴别；同样在这种情况下，我们认为检测到与H2-A2相同的H-Ae间期提示前一种类型的旁路。我们得出结论，只有除了其他作者提出的电生理标准外，还存在与H2A2相同的H-Ae间期，才能诊断隐匿性房室旁路。
