Kadish A H, Morady F
Department of Internal Medicine, University of Michigan Medical School, Ann Arbor.
J Cardiovasc Electrophysiol. 1993 Jun;4(3):239-52. doi: 10.1111/j.1540-8167.1993.tb01227.x.
Standard electrophysiologic techniques generally allow discrimination among mechanisms of paroxysmal supraventricular tachycardia. The purpose of this study was to determine whether the response of paroxysmal supraventricular tachycardia to atrial and ventricular overdrive pacing can help determine the tachycardia mechanism.
Fifty-three patients with paroxysmal supraventricular tachycardia were studied. Twenty-two patients had the typical form of atrioventricular (AV) junctional (nodal) reentry, 18 patients had orthodromic AV reentrant tachycardia, 10 patients had atrial tachycardia, and 3 patients had the atypical form of AV nodal reentrant tachycardia. After paroxysmal supraventricular tachycardia was induced, 15-beat trains were introduced in the high right atrium and right ventricular apex sequentially with cycle lengths beginning 10 msec shorter than the spontaneous tachycardia cycle length. The pacing cycle length was shortened in successive trains until a cycle of 200 msec was reached or until tachycardia was terminated. Several responses of paroxysmal supraventricular tachycardia to overdrive pacing were useful in distinguishing atrial tachycardia from other mechanisms of paroxysmal supraventricular tachycardia. During decremental atrial overdrive pacing, the curve relating the pacing cycle length to the VA interval on the first beat following the cessation of atrial pacing was flat or upsloping in patients with AV junctional reentry or AV reentrant tachycardia, but variable in patients with atrial tachycardia. AV reentry and AV junctional reentry could always be terminated by overdrive ventricular pacing whereas atrial tachycardia was terminated in only one of ten patients (P < 0.001). The curve relating the ventricular pacing cycle length to the VA interval on the first postpacing beat was flat or upsloping in patients with AV junctional reentry and AV reentry, but variable in patients with atrial tachycardia. The typical form of AV junctional reentry could occasionally be distinguished from other forms of paroxysmal supraventricular tachycardia by the shortening of the AH interval following tachycardia termination during constant rate atrial pacing.
Atrial and ventricular overdrive pacing can rapidly and reliably distinguish atrial tachycardia from other mechanisms of paroxysmal supraventricular tachycardia and occasionally assist in the diagnosis of other tachycardia mechanisms. In particular, the ability to exclude atrial tachycardia as a potential mechanism for paroxysmal supraventricular tachycardia has important implications for the use of catheter ablation techniques to cure paroxysmal supraventricular tachycardia.
标准的电生理技术通常能够区分阵发性室上性心动过速的机制。本研究的目的是确定阵发性室上性心动过速对心房和心室超速起搏的反应是否有助于确定心动过速机制。
对53例阵发性室上性心动过速患者进行了研究。22例患者为典型的房室（AV）交界区（结性）折返，18例患者为顺向性AV折返性心动过速，10例患者为房性心动过速，3例患者为非典型AV结性折返性心动过速。诱发阵发性室上性心动过速后，在高位右心房和右心室尖部依次引入15次搏动的序列，起始周期长度比自发心动过速周期长度短10毫秒。在连续的序列中缩短起搏周期长度，直至达到200毫秒的周期或直至心动过速终止。阵发性室上性心动过速对超速起搏的几种反应有助于将房性心动过速与阵发性室上性心动过速的其他机制区分开来。在递减性心房超速起搏期间，对于房室交界区折返或房室折返性心动过速患者，在心房起搏停止后的第一个搏动上，将起搏周期长度与VA间期相关的曲线是平坦的或向上倾斜的，但对于房性心动过速患者则是可变的。房室折返和房室交界区折返总是可以通过超速心室起搏终止，而房性心动过速在10例患者中仅1例被终止（P<0.001）。对于房室交界区折返和房室折返患者，将心室起搏周期长度与起搏后第一个搏动的VA间期相关的曲线是平坦的或向上倾斜的，但对于房性心动过速患者则是可变的。在恒定频率心房起搏期间，心动过速终止后AH间期缩短，偶尔可将典型的房室交界区折返与阵发性室上性心动过速的其他形式区分开来。
心房和心室超速起搏能够快速、可靠地将房性心动过速与阵发性室上性心动过速的其他机制区分开来，偶尔有助于诊断其他心动过速机制。特别是，排除房性心动过速作为阵发性室上性心动过速潜在机制的能力对于使用导管消融技术治疗阵发性室上性心动过速具有重要意义。
