Medeiros C M, Lucchese F A
Institute of Cardiology, Porto Alegre, Brazil.
J Electrocardiol. 1989 Jul;22(3):249-56. doi: 10.1016/0022-0736(89)90036-8.
An analysis of the electrocardiogram of a patient with the permanent form of junctional reciprocating tachycardia is presented. The patient demonstrated near-incessant tachycardia, with a 1:1 atrioventricular relationship and a retrograde P wave (P') occurring closer to the succeeding QRS complexes (ie, with a P'R interval that is shorter than the RP' interval). Each tachycardia episode was characterized by alternating short and long cardiac cycles due to alternation of retrograde conduction time (RP' interval), retrograde Wenckebach periodicity, and an even number of ectopic P' waves. The authors propose that there is an accessory AV connection with decremental functional properties that arborizes into two atrial branches with different conduction times. The fast branch initially exhibits a 3:2 retrograde conduction block followed by a cycle length-dependent 2:1 retrograde conduction block, thereby permitting alternate use of the slow branch, which is the weakest component of the reciprocating process.
本文呈现了对一名持续性交界性折返性心动过速患者的心电图分析。该患者表现为近乎持续性心动过速，房室关系为1:1，逆行P波（P'）更靠近后续的QRS波群（即P'R间期短于RP'间期）。每次心动过速发作的特征是由于逆行传导时间（RP'间期）交替、逆行文氏周期以及异位P'波数量为偶数，导致心动周期长短交替。作者提出存在一条具有递减功能特性的附加房室连接，该连接分支形成两条传导时间不同的心房分支。快速分支最初表现为3:2逆行传导阻滞，随后是周期长度依赖性的2:1逆行传导阻滞，从而允许交替使用缓慢分支，而缓慢分支是折返过程中最薄弱的部分。
