Evidence of Three Clinical Subgroups in Patients With Dual Atrioventricular Nodal Pathways

• Published in: The American journal of the medical sciences 1997-07, Vol.314 (1), p.11-16
• Main Authors: Serita, Takumi, Kitano, Kouei, Tasaki, Hirofumi, Mitarai, Sayaka, Yoshiwara, Yumiko, Irita, Akiko, Iwamoto, Keiji, Ueyama, Chiaki, Seto, Shinji, Hayano, Motonobu, Yano, Katsusuke
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Atrioventricular nodal reentrant tachycardia; Atrioventricular Node - physiopathology; Biological and medical sciences; Cardiac dysrhythmias; Cardiology. Vascular system; Child; Clinical subgroups; Dual atrioventricular nodal pathways; Electrocardiography; Female; Heart; Heart Block - physiopathology; Humans; Male; Medical sciences; Middle Aged; Second-degree atrioventricular block; Tachycardia, Atrioventricular Nodal Reentry - physiopathology
• ISSN: 0002-9629; 1538-2990
• DOI: 10.1016/S0002-9629(15)40149-1

We attempted to test the hypothesis that dual atrioventricular (A-V) nodal pathways with second-degree atrioventricular block (2nd A-V block) present as a different clinical entity from those with A-V nodal reentrantta- chycardia (AVNRT). By evaluation with Holter monitoring (2.9 ± 2.5 recordings/patient) and 12- lead electrocardiogram (11.9 ± 11.6), 177 patients with dual A-V nodal pathways could be divided into three subgroups. Thirty-two patients had 2nd A-V block only (2nd A-V block group), 57 had AVNRT only (AVNRT group), 88 had neither 2nd A-V block nor AVNRT (silent group), and none had 2nd A-V block and AVNRT both. Electrophysiologic studies showed that the atrio-His interval was significantly greater (P < 0.0001) and the maximal 1:1 atrioventricular conduction rate was lower (P < 0.0001) in the 2nd A-V block group than in the other two groups. These differences were nullified after the administration of atropine. These results suggest that patients with dual A-V nodal pathways can be classified into three clinical subgroups based on the presence of either 2nd A-V block or AVNRT. We suggest also that patients of the 2nd A-V block group may have a more augmented vagal tone on the A-V node than the other two groups.