Wood M A, Simpson P M, Stambler B S, Herre J M, Bernstein R C, Ellenbogen K A
Department of Medicine (Cardiology), Medical College of Virginia, McGuire Veterans Administration Medical Center, Richmond 23298, USA.
Circulation. 1995 May 1;91(9):2371-7. doi: 10.1161/01.cir.91.9.2371.
Technological limitations have precluded investigation of long-term temporal patterns of ventricular tachyarrhythmia recurrences. Newer implantable cardioverter-defibrillators permit such analyses by accurately recording the time and date of tachycardia detections during long-term follow-up. This study tests the hypothesis that ventricular tachycardia occurrences are randomly distributed over time in individual patients.
The time and date of 727 episodes of ventricular tachyarrhythmias were recorded from the data logs of 31 patients with implantable cardioverter-defibrillators followed for a median of 177 days (range, 7 to 782 days). All patients had three or more ventricular tachycardia detections and no detections from causes other than ventricular arrhythmias. In 28 of 31 patients, the distribution of the interdetection time intervals during follow-up differed significantly (all P < .01) from an exponential model distribution of interdetection intervals that assumed that detections were equally likely to occur at any time during follow-up (random). The Kolmogorov-Smirnov goodness-of-fit test was used to compare sample and model distributions. In each patient, the nonrandom distributions resulted from a preponderance of interdetection time intervals that were shorter than predicted by the random model, resulting in a temporal clustering of arrhythmic events. The interdetection interval was < or = 1 hour and < or = 91 hours for 55% and 78% of all intervals, respectively. When only those episodes receiving shock or antitachycardia pacing therapy were analyzed, 25 of 29 patients still manifested nonrandom distributions (all P < .01). When only episodes with tachycardia rates > 240 beats per minute were analyzed, 11 of 13 patients manifested non-random distributions (all P < .01).
Ventricular tachycardia detections and delivered antitachycardia therapies by implantable cardioverter-defibrillators are nonrandomly distributed throughout long-term follow-up in the majority of patients. The temporal clustering of these arrhythmic events may allow preemptive antiarrhythmic therapy and should be considered in the design of therapy based on suppression of spontaneous ventricular arrhythmias to statistically derived end points.
技术限制使得对室性快速性心律失常复发的长期时间模式的研究受到阻碍。新型植入式心脏复律除颤器能够通过在长期随访期间准确记录心动过速检测的时间和日期来进行此类分析。本研究检验了室性心动过速发作在个体患者中随时间随机分布的假设。
从31例植入式心脏复律除颤器患者的数据日志中记录了727次室性快速性心律失常发作的时间和日期，这些患者的随访时间中位数为177天（范围7至782天）。所有患者有三次或更多次室性心动过速检测，且无除室性心律失常以外原因的检测。在31例患者中的28例，随访期间检测间隔时间的分布与假设检测在随访期间任何时间发生可能性相同（随机）的检测间隔指数模型分布有显著差异（所有P <.01）。采用Kolmogorov-Smirnov拟合优度检验来比较样本分布和模型分布。在每个患者中，非随机分布是由于检测间隔时间大多短于随机模型预测的时间，导致心律失常事件的时间聚集。所有间隔中分别有55%和78%的检测间隔时间≤1小时和≤91小时。当仅分析那些接受电击或抗心动过速起搏治疗的发作时，29例患者中的25例仍表现出非随机分布（所有P <.01）。当仅分析心动过速心率>240次/分钟的发作时，13例患者中的11例表现出非随机分布（所有P <.01）。
在大多数患者的长期随访中，植入式心脏复律除颤器检测到的室性心动过速及给予的抗心动过速治疗并非随机分布。这些心律失常事件的时间聚集可能允许进行预防性抗心律失常治疗，并且在基于抑制自发性室性心律失常至统计学得出的终点的治疗设计中应予以考虑。
