Participation of fast and slow A-V nodal pathways in tachycardias complicating the Wolff-Parkinson-White syndrome. Report of a case.
Electrophysiological studies in one patient with type B pre-excitation and dual A-V nodal pathway revealed several types of paroxysmal narrow QRS tachycardia (PSVT). One type of PSVT reflected antegrade fast A-V nodal pathway and retrograde anomalous pathway conduction. This PSVT was characterized by early retorgrade activation of right atrial appendage, P following QRS and cycle length of 290 to 350 msec. A second PSVT reflected antegrade slow A-V nodal pathway and retrograde anomalous pathway conduction. This PSVT was characterized by early retrograde activation of right atrial appendage, P following QRS, and cycle length of 440 msec. A third PSVT reflected A-V nodal re-entrance with antegrade slow pathway and retrograde fast pathway conduction. This PSVT was characterized by normal retrograde atrial activation sequences, P simultaneous with QRS, and cycle length of 320 msec. All PSVT inductions could be explained in terms of antegrade and retrograde properties of fast and slow A-V nodal and anomalous pathways.
D000328:Adult; D001283:Atrioventricular Node / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D009431:Neural Conduction; D013614:Tachycardia, Paroxysmal / Q000209:etiology / Q000503:physiopathology*; D013997:Time Factors; D014927:Wolff-Parkinson-White Syndrome / Q000150:complications / Q000503:physiopathology*