Author + information
- Received April 16, 2015
- Revision received December 17, 2015
- Accepted December 27, 2015
- Published online June 1, 2016.
- Jong Sung Park, MDa,b,
- HyeJin Hwang, MD, PhDa,
- Boyoung Joung, MD, PhDa,
- Moon-Hyoung Lee, MD, PhDa and
- Sung Soon Kim, MD, PhDa,c,∗ ()
- aDivision of Cardiology, Cardiovascular Center, Yonsei University Health System, Seoul, Republic of Korea
- bDivision of Cardiology, Cardiovascular Center, Dong-A University Medical Center, Busan, Republic of Korea
- cDivision of Cardiology, Korean Armed Forces Capital Hospital, Gyeonggi-do, Republic of Korea
- ↵∗Reprint requests and correspondence:
Dr. Sung Soon Kim, Division of Cardiology, Severance Cardiovascular Center, Yonsei University Health System, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea.
Objectives This study examined the clinical and electrocardiographic characteristics and electrophysiologic determinants of sustained slow pathway conduction (SSPC) during sinus rhythm.
Background SSPC during sinus rhythm in presence of dual atrioventricular (AV) nodal pathways has not been thoroughly studied.
Methods We studied 30 consecutive patients (19 men), whose median age was 31 years (interquartile range: 22 to 48 years); their electrocardiograms revealed 2 different PR intervals during nearly identical sinus rates. We measured the short and long PR intervals and their differences and examined the electrophysiologic determinants of SSPC during slow pathway (SP) ablation in 12 patients.
Results Among the 30 patients, 21 (70%) complained of major symptoms. The short and long PR intervals measured 202 ± 42 ms and 472 ± 110 ms, respectively, and their mean difference measured 270 ± 101 ms. During electrophysiologic studies, dual AV nodal and SSPC were observed in all patients. A markedly prolonged refractory period (593 ± 116 ms) and retrograde conduction block over the fast pathway (FP) were observed over a range of sinus cycle lengths (CLs). Ablation of the SP in 11 patients promoted FP conduction and shortened its effective refractory period from 593 ± 116 ms to 288 ± 90 ms. Over a median follow-up of 2 years (interquartile range: 1 to 3 years), all patients remained asymptomatic and without recurrences of SSPC or AV block.
Conclusions Two distinct PR intervals during sinus rhythm indicated the presence of dual AV nodal pathways. SSPC was promoted by a markedly impaired bidirectional conduction over the FP at critical sinus CL. SP ablation safely and effectively eliminated SSPC in symptomatic patients.
- atrioventricular node
- catheter ablation
- dual atrioventricular nodal pathway
- fast atrioventricular nodal pathway
- slow atrioventricular nodal pathway
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received April 16, 2015.
- Revision received December 17, 2015.
- Accepted December 27, 2015.
- American College of Cardiology Foundation