Paroxysmal supraventricular tachycardia (PSVT) is a common arrhythmia in patients with and without organic heart disease. It has generally been believed to reflect either reentrant mechanisms or rapid firing of ectopic foci. Recent clinical and experimental observations have suggested that most PSVT appears to reflect reentrance.1-6 In man, the occurrence of reentrance has been demonstrated in the sinus node,7-9 atrium,9 atrioventricular node,1-6 and possibly the His bundle.10
Longitudinal dissociation of a conducting structure (for example, the atrioventricular node) allows reentry to occur11-14 (Fig 1, left). With dissociation into two pathways, a premature impulse encounters refractoriness (unidirectional block) in one pathway and conducts slowly in the other pathway. The previously blocked pathway recovers for retrograde conduction during the period of slow conduction. If the two pathways are connected by a final common pathway, the impulse can reenter the previously blocked pathway and return to the chamber of origin. While conducting retrograde,
Wu D, Denes P. Mechanisms of Paroxysmal Supraventricular Tachycardia. Arch Intern Med. 1975;135(3):437–442. doi:10.1001/archinte.1975.00330030087009
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: