Anastasiou-Nana M I, Menlove R L, Nanas J N, Anderson J L
Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City.
Circulation. 1988 Aug;78(2):286-95. doi: 10.1161/01.cir.78.2.286.
Previous determinations of spontaneous variability in ventricular arrhythmia have often been based on measurements from consecutive days in small patient populations, whereas clinical determinations of drug efficacy typically compare measurements at intervals of 1 week and longer to baseline. We, therefore, sought to determine whether spontaneous arrhythmia variability changes as a function of time during periods ranging from 1 day to 1 year or longer. The percent reduction in the frequency of total premature ventricular complexes (PVCs) and repetitive ventricular beats required to show true drug effect rather than spontaneous variability in PVCs was determined in 47 consecutive patients with chronic ventricular arrhythmias who underwent multiple ambulatory monitor recordings while off active drug treatment (during placebo therapy). The variability in PVC rate was determined during the intervals of 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks, and 1 year or longer. The percent reductions in total PVCs required to exceed the 95% confidence limits of spontaneous variability at these intervals were 55%, 85%, 86%, 93%, 96%, and 96%, respectively. Corresponding values for repetitive beats were 75%, 95%, 92%, 95%, 94%, and 98%, respectively. The percent increase in total PVCs and repetitive beats required to establish "arrhythmia aggravation" caused by an antiarrhythmic drug with a 95% confidence limit also was calculated for this study population and was 124% and 303%, respectively, at 1-day intervals and 2,269% and 4,091%, respectively, at 1-year (or longer) intervals for the 24-hour monitor recordings. Variability was not substantially affected by underlying heart disease or ejection fraction. PVC rate showed a modest negative correlation with variability (r = 0.3). Thus, variability is substantially greater at 1 week, the usual time for clinical assessment of antiarrhythmic drug efficacy, than at 1 day (p less than 0.01). Suppression of more than 85% of total PVCs and more than 95% of repetitive beats appears to be necessary after 1-2 weeks to be confident of a true drug effect. Even greater variability is observed after 1 month and up to 1 year so that reductions of up to 95% in total PVCs and 98% in repetitive beats may represent spontaneous change.(ABSTRACT TRUNCATED AT 400 WORDS)
以往对室性心律失常自发变异性的测定通常基于小患者群体连续数天的测量数据，而药物疗效的临床测定通常将间隔1周及更长时间的测量数据与基线数据进行比较。因此，我们试图确定在从1天到1年或更长时间的期间内，自发心律失常变异性是否随时间变化。在47例慢性室性心律失常患者中，在停用活性药物治疗（安慰剂治疗期间）时进行多次动态心电图记录，以确定显示真正药物效果而非室性早搏（PVC）自发变异性所需的总室性早搏和重复性室性搏动频率的降低百分比。在1天、1周、2周、3周、4周以及1年或更长时间的间隔内测定PVC频率的变异性。在这些间隔内，超过自发变异性95%置信限所需的总PVC降低百分比分别为55%、85%、86%、93%、96%和96%。重复性搏动的相应值分别为75%、95%、92%、95%、94%和98%。本研究人群中，建立抗心律失常药物导致的“心律失常加重”（95%置信限）所需的总PVC和重复性搏动增加百分比也进行了计算，对于24小时动态心电图记录，在1天间隔时分别为124%和303%，在1年（或更长）间隔时分别为2269%和4091%。变异性并未受到基础心脏病或射血分数的显著影响。PVC频率与变异性呈适度负相关（r = 0.3）。因此，在通常用于抗心律失常药物疗效临床评估的1周时的变异性显著大于1天时的变异性（p小于0.01）。在1 - 2周后，似乎有必要抑制超过85%的总PVC和超过95%的重复性搏动，才能确信有真正的药物效果。在1个月后直至1年观察到更大的变异性，以至于总PVC降低高达95%和重复性搏动降低98%可能代表自发变化。（摘要截断于400字）
