Satullo G, Oreto G, Luzza F, Consolo A, Donato A
Istituto Pluridisciplinare di Clinica Medica, Università di Messina, Italy.
Am Heart J. 1991 May;121(5):1507-12. doi: 10.1016/0002-8703(91)90159-f.
Sinus parasystole is the expression of a protected nondominant sinus pacemaker, which is totally independent of the dominant rhythm. Two forms of sinus parasystole are described: (1) an active form, where both the dominant and the parasystolic pacemakers are located within the sinus node and (2) a passive form, where the basic rhythm is ectopic and the sinus pacemaker is protected as a result of complete retrograde SA block. Three cases of sinus parasystole are analyzed. In the active form of the arrhythmia the parasystolic sinus P waves are identical to those of the basic sinus rhythm. The diagnosis is suggested by variably coupled premature sinus P waves occurring with mathematically related intervals. This relationship between the parasystolic intervals can not be precise whenever complicating factors such as modulation occur. The recognition of active sinus parasystole is difficult, since the parasystolic P waves do not differ from basic P waves, so that the pattern resembles that of sinus arrhythmia or sinus extrasystoles. The passive form of sinus parasystole is more easily recognized due to the clear-cut difference between the dominant ectopic atrial waves and the "parasystolic" sinus P waves, which manifest with variable coupling intervals and reflect mathematically related intervals in between.
窦性并行心律是一种受保护的非优势窦性起搏点的表现形式，它完全独立于主导节律。窦性并行心律有两种类型：（1）主动型，主导起搏点和并行起搏点均位于窦房结内；（2）被动型，基本节律为异位节律，由于完全性逆行性窦房阻滞，窦性起搏点受到保护。本文分析了3例窦性并行心律。在心律失常的主动型中，并行窦性P波与基本窦性节律的P波相同。诊断依据是出现与数学相关间期的不同联律间期的窦性早搏P波。当出现如调制等复杂因素时，并行间期之间的这种关系可能不精确。主动型窦性并行心律的识别较为困难，因为并行P波与基本P波无异，所以其图形类似于窦性心律失常或窦性早搏。由于主导异位房波与“并行”窦性P波之间有明显差异，被动型窦性并行心律更容易识别，后者表现为可变的联律间期，并反映其间的数学相关间期。
