Oreto G, Satullo G, Luzza F, Donato A, Saccá C M, Arrigo F, Consolo F, Schamroth L
Istituto Pluridisciplinare di Clinica Medica e Terapia Medica Generale e Speciale dell'Universitá degli Studi di Messina, Italy.
Am Heart J. 1988 Jan;115(1 Pt 1):121-33. doi: 10.1016/0002-8703(88)90527-3.
Fifteen cases of ventricular parasystole were analyzed to determine whether the interectopic intervals were regular, as expressed by long intervals being exact multiples of the short ones, or not. The regularity of the interectopic intervals was assessed by means of the variation index: the ratio of the maximal difference between various measurements of the parasystolic cycle length and the mean parasystolic cycle length. Three out of 15 cases had a variation index less than 5, and were classified as "regular parasystole." Twelve cases were associated with a variation index greater than 7.5, and were classified as "irregular parasystole." The cases of irregular parasystole were then analyzed to determine whether the variability of the interectopic intervals was casual or dependent on action of the sinus beats. A parasystolic resetting by critically timed sinus impulses (a form of intermittent parasystole) was evident in three cases. The irregularity in the remaining nine cases was due to modulation (viz., due to electrotonic influence exerted by the sinus beats on the parasystolic focus). In every case of modulated parasystole a phase-response curve was constructed, which enabled an analysis of all the interectopic intervals on the basis of a time-dependent effect exerted by the sinus impulses on an otherwise rhythmic parasystolic focus.
分析了15例室性并行心律病例，以确定异位搏动间期是否规则，即长间期是否为短间期的精确倍数。通过变异指数评估异位搏动间期的规则性：并行心律周期长度各种测量值之间的最大差值与并行心律平均周期长度的比值。15例中有3例变异指数小于5，被归类为“规则并行心律”。12例变异指数大于7.5，被归类为“不规则并行心律”。然后对不规则并行心律病例进行分析，以确定异位搏动间期的变异性是偶然的还是取决于窦性搏动的作用。在3例中，适时的窦性冲动引起并行心律重整（一种间歇性并行心律形式）明显。其余9例的不规则性是由于调制（即，由于窦性搏动对并行心律起搏点施加的电紧张影响）。在每例调制并行心律中构建了相位反应曲线，这使得能够基于窦性冲动对原本有节律的并行心律起搏点施加的时间依赖性效应来分析所有异位搏动间期。
