OBJECTIVES: The purpose of this study was to investigate the electrophysiologic profile of the pulmonary veins (PVs) and left atrium (LA) in response to autonomic manipulation. BACKGROUND: The parasympathetic innervation of the PVs and posterior left atrium (PLA) is thought to contribute to focal atrial fibrillation (AF). We hypothesized that autonomic effects would be more prominent in these regions. METHODS: In 14 dogs, epicardial mapping was performed in the PVs, PLA, and left atrial appendage (LAA) under the following conditions: baseline, 20-Hz cervical vagal stimulation (VS), propranolol (P), P + VS, and P + atropine. Effective refractory periods (ERPs) were measured, and conduction vectors were computed at multiple sites. Western blotting and immunostaining were performed for IKAch (Kir3.1/3.4). RESULTS: The VS and P + VS caused more ERP shortening in the PV and PLA than in the LAA. The P + atropine caused greatest ERP prolongation in the LAA. Cumulative ERP change (ERP difference between P + VS and P + atropine) was greatest in the LAA and corresponded with expression of Kir3.1/3.4 (LAA > PLA > or = PV). The ERP change in response to vagal manipulation was most heterogeneous in the PLA; this corresponded with a pronounced heterogeneity of Kir3.1 distribution in the PLA. With VS and/or P, there was evidence of regional conduction delay in the PVs with a significant change in activation direction. Similar activation changes were not seen in the PLA and LAA. CONCLUSIONS: The PVs and PLA demonstrate unique activation and repolarization characteristics in response to autonomic manipulation. The heterogeneity of vagal responses correlates with the pattern of IKAch distribution in the LA. The peculiar autonomic characteristics of the PVs and PLA might create substrate for re-entry and AF.
OBJECTIVES: The purpose of this study was to investigate the electrophysiologic profile of the pulmonary veins (PVs) and left atrium (LA) in response to autonomic manipulation. BACKGROUND: The parasympathetic innervation of the PVs and posterior left atrium (PLA) is thought to contribute to focal atrial fibrillation (AF). We hypothesized that autonomic effects would be more prominent in these regions. METHODS: In 14 dogs, epicardial mapping was performed in the PVs, PLA, and left atrial appendage (LAA) under the following conditions: baseline, 20-Hz cervical vagal stimulation (VS), propranolol (P), P + VS, and P + atropine. Effective refractory periods (ERPs) were measured, and conduction vectors were computed at multiple sites. Western blotting and immunostaining were performed for IKAch (Kir3.1/3.4). RESULTS: The VS and P + VS caused more ERP shortening in the PV and PLA than in the LAA. The P + atropine caused greatest ERP prolongation in the LAA. Cumulative ERP change (ERP difference between P + VS and P + atropine) was greatest in the LAA and corresponded with expression of Kir3.1/3.4 (LAA > PLA > or = PV). The ERP change in response to vagal manipulation was most heterogeneous in the PLA; this corresponded with a pronounced heterogeneity of Kir3.1 distribution in the PLA. With VS and/or P, there was evidence of regional conduction delay in the PVs with a significant change in activation direction. Similar activation changes were not seen in the PLA and LAA. CONCLUSIONS: The PVs and PLA demonstrate unique activation and repolarization characteristics in response to autonomic manipulation. The heterogeneity of vagal responses correlates with the pattern of IKAch distribution in the LA. The peculiar autonomic characteristics of the PVs and PLA might create substrate for re-entry and AF.
Authors: Jason Ng; Roger Villuendas; Ivan Cokic; Jorge E Schliamser; David Gordon; Hemanth Koduri; Brandon Benefield; Julia Simon; S N Prasanna Murthy; Jon W Lomasney; J Andrew Wasserstrom; Jeffrey J Goldberger; Gary L Aistrup; Rishi Arora Journal: Circ Arrhythm Electrophysiol Date: 2011-03-18
Authors: Kalyanam Shivkumar; Olujimi A Ajijola; Inder Anand; J Andrew Armour; Peng-Sheng Chen; Murray Esler; Gaetano M De Ferrari; Michael C Fishbein; Jeffrey J Goldberger; Ronald M Harper; Michael J Joyner; Sahib S Khalsa; Rajesh Kumar; Richard Lane; Aman Mahajan; Sunny Po; Peter J Schwartz; Virend K Somers; Miguel Valderrabano; Marmar Vaseghi; Douglas P Zipes Journal: J Physiol Date: 2016-06-14 Impact factor: 5.182
Authors: Gary L Aistrup; Ivan Cokic; Jason Ng; David Gordon; Hemanth Koduri; Suzanne Browne; Dorina Arapi; Yogita Segon; Jacob Goldstein; Abigail Angulo; J Andrew Wasserstrom; Jeffrey J Goldberger; Alan H Kadish; Rishi Arora Journal: Heart Rhythm Date: 2011-08-25 Impact factor: 6.343
Authors: Gary L Aistrup; Roger Villuendas; Jason Ng; Annette Gilchrist; Thomas W Lynch; David Gordon; Ivan Cokic; Steven Mottl; Rui Zhou; David A Dean; J Andrew Wasserstrom; Jeffrey J Goldberger; Alan H Kadish; Rishi Arora Journal: Cardiovasc Res Date: 2009-05-20 Impact factor: 10.787