Randall W C, Wehrmacher W H, Jones S B
J Thorac Cardiovasc Surg. 1981 Nov;82(5):797-800.
Definitive subsidiary atrial pacemakers (SAPs) exist within the crista terminalis and in the atrial free wall tissue at the junction of the inferior vena cava and the inferior right atrium. These pacemakers are capable of maintaining cardiac rhythm at a rate intermediate between that of the sinoatrial (SA) nodal and atrioventricular (AV) junctional pacemakers upon default of the normal SA nodal cells. The conventional concept of a single (junctional) escape mechanism needs to be updated by recognition of these SAP sites, which are under comprehensive autonomic regulation. A great variety of clinically important cardiac syndromes require understanding of the SAPs, not only for diagnostic significance but also for therapeutic consideration. SAPs differ from the SA pacemakers in that they possess intrinsically slower spontaneous rates and are less stable. There is early competition among them for instantaneous dominance. They are more responsive to both sympathetic and parasympathetic control, and they are initially more susceptible to underdrive stimulation by another pacemaker (whether artificial or natural) than are pacemakers with the SA node.
明确的辅助心房起搏器（SAPs）存在于界嵴以及下腔静脉与右心房下部交界处的心房游离壁组织中。当正常的窦房（SA）结细胞功能缺失时，这些起搏器能够以介于窦房结和房室（AV）交界区起搏器之间的速率维持心律。由于认识到这些受全面自主神经调节的SAP部位，单一（交界性）逸搏机制的传统概念需要更新。多种具有临床重要性的心脏综合征需要了解SAPs，这不仅具有诊断意义，还具有治疗考量价值。SAPs与窦房结起搏器不同，它们具有内在较慢的自发频率且稳定性较差。它们之间存在早期竞争以获得瞬时主导地位。它们对交感神经和副交感神经控制的反应更强，并且与窦房结起搏器相比，它们最初更容易受到另一个起搏器（无论是人工的还是天然的）的超速抑制刺激。
