Mann D E, Florek R C, Reiter M J
Cardiology Division, University of Colorado Health Sciences Center, Denver 80262.
J Electrocardiol. 1992 Jan;25(1):33-8. doi: 10.1016/0022-0736(92)90127-l.
To assess the effect of pacing drive cycle length on induction of sustained monomorphic ventricular tachycardia, 40 patients were prospectively studied in the drug-free state. Ventricular extrastimuli were sequentially delivered at the same coupling interval at each of three drive cycle lengths (600, 500, and 400 ms) before the coupling interval was shortened and the process repeated. This protocol was continued until sustained monomorphic ventricular tachycardia was induced at all three drive cycle lengths or until pacing was completed through three extrastimuli. Of the 27 patients in whom sustained monomorphic ventricular tachycardia was induced, tachycardia was induced at all 3 drive cycle lengths in 12 (44%), only 2 drive cycle lengths in 11 (41%), and only 1 drive cycle length in 4 (15%) patients. Although the yield of inducible ventricular tachycardia increased with each additional extrastimulus, this yield increased even further with the use of multiple drive cycle lengths. In 10 of 11 patients, failure to induce ventricular tachycardia at any drive cycle length was not due to failure to achieve at that drive cycle length the critical extrastimulus coupling interval required to induce tachycardia at other drive cycle lengths. Induction of sustained monomorphic ventricular tachycardia is often drive cycle length specific, and failure to induce tachycardia cannot be explained by failure to achieve critically short coupling intervals. Pacing at multiple drive cycle lengths increases the yield of induced ventricular tachycardia.
为评估起搏驱动周期长度对持续性单形性室性心动过速诱发的影响，对40例患者在无药物状态下进行了前瞻性研究。在缩短联律间期并重复该过程之前，在三个驱动周期长度（600、500和400毫秒）中的每一个上，以相同的联律间期依次发放室性期外刺激。持续该方案，直到在所有三个驱动周期长度均诱发持续性单形性室性心动过速，或直到通过三个期外刺激完成起搏。在诱发持续性单形性室性心动过速的27例患者中，12例（44%）在所有3个驱动周期长度均诱发心动过速，11例（41%）仅在2个驱动周期长度诱发心动过速，4例（15%）仅在1个驱动周期长度诱发心动过速。虽然每增加一个期外刺激，可诱发性室性心动过速的发生率就会增加，但使用多个驱动周期长度时，该发生率会进一步增加。在11例患者中的10例中，在任何驱动周期长度均未能诱发室性心动过速，并非是由于在该驱动周期长度未达到诱发其他驱动周期长度心动过速所需的关键期外刺激联律间期。持续性单形性室性心动过速的诱发通常具有驱动周期长度特异性，未能诱发心动过速不能用未达到极短联律间期来解释。在多个驱动周期长度进行起搏可增加诱发性室性心动过速的发生率。
