Electrophysiologic Characteristics and Radiofrequency Catheter Ablation in Atrioventricular Node Reentrant Tachycardia with Second-Degree Atrioventricular Block |
| |
Authors: | SHIH-HUANG LEE M.D. SHIH-ANN CHEN M.D. CHING-TAI TAI M.D. CHERN-EN CHIANG M.D. ZU-CHI WEN M.D. KWO-CHANG UENG M.D. CHUEN-WANG CHIOU M.D. YI-JBN CHEN M.D. WEN-CHUNG YU M.D. JIN-LONG HUANG M.D. JUN-JACK CHENG M.D. MAU-SONG CHANG M.D. |
| |
Affiliation: | Division of Cardiology, Department of Medicine, and Institute of Clinical Medicine, National Yang-Ming University and Veterans General Hospital-Taipei, Taipei, Taiwan;;Department of Medicine, Shin-Kong Memorial Hospital, Taipei, Taiwan;;Division of Cardiology, Department of Medicine, Veterans General Hospital-Taichung, Taichung, Taiwan, Republic of China |
| |
Abstract: | Second-Degree AV Block During AVNRT. Introduction : Detailed electrophysiologic study of AV nodal reentrant tachycardia (AVNRT) with 2:1 AV block has been limited. Methods and Results : Six hundred nine consecutive patients with AVNRT underwent electrophysiologic study and radiofrequency catheter ablation of the slow pathway. Twenty-six patients with 2:1 AV block during AVNRT were designated as group I, und those without this particular finding were designated as group II. The major findings of the present study were: (1) group I patients had better anterograde and retrograde AV nodal function, shorter tachycardia cycle length (during tachycardia with 1:1 conduction) (307 ± 30 vs 360 ± 58 msec, P < 0.001), and higher incidence of transient bundle branch block during tachycardia (18/26 vs 43/609, P < 0.001) than group II patients: (2) 21 (80.8%) group I patients had alternans of AA intervals during AVNRT with 2:1 AV block. Longer AH intervals (264 ± 26 vs 253 ± 27 msec, P = 0.031) were associated with the blocked beats. However, similar HA intervals (51 ± 12 vs 50 ± 12 msec, P = 0.363) and similar HV intervals (53 ± 11 vs 52 ± 12, P = 0.834) were found in the blocked and conducted beats; (3) ventricular extrastimulation before or during the His-bundle refractory period bundle could convert 2:1 AV block to 1:1 AV conduction. Conclusions : Fast reentrant circuit, rather than underlying impaired conduction of the distal AV node or infranodal area, might account for second-degree AV block during AVNRT. Slow pathway ablation is safe and effective in patients who have AVNRT with 2:1 AV block. |
| |
Keywords: | atrioventricular nodal reentrant tachycardia atrioventricular block electrophysiologic study radiofrequency catheter ablation |
|
|