title: The effects of selective stellate ganglion manipulation on ventricular refractoriness and excitability.
abstract: The effects of selective stellate ganglion stimulation or stellectomy on ventricular excitability were studied in 30 open chest mongrel dogs anesthetized with alpha-chloralose. The effective refractory period (ERP) and strength interval curves (stimulus intensity [S2] = twice the diastolic threshold [ERP], and 2, 3, 5, 7, and 14 mA) were determined using bipolar epicardial electrodes placed in the mid-anterior wall of the right ventricle (RV) and the mid-posterolateral wall of the left ventricle (LV) during left stellate ganglion stimulation (LSGSt, n = 8) or right stellate ganglion stimulation (RSGSt, n = 8), or after left stellectomy (LSGEx, n = 7) or right stellectomy (RSGEx, n = 7). LSGEx prolonged ERP-LV (172 +/- 9 vs 167 +/- 8 msec, P < 0.05) and ERP-RV (163 +/- 10 vs 158 +/- 14 msec, P < 0.05). RSGEx prolonged ERP-LV (168 +/- 17 vs 162 +/- 15 msec, P < 0.01) and ERP-RV (166 +/- 14 vs 160 +/- 13 msec, P < 0.01), and the times of the strength interval curves obtained for each S2 intensity in both ventricles. LSGSt decreased ERP-LV (157 +/- 11 vs 163 +/- 12 msec, P < 0.01) and ERP-RV (147 +/- 18 vs 157 +/- 17 msec, P < 0.05), and the times of the strength interval curves obtained for each S2 intensity in both ventricles. RSGSt did not significantly decreased ERP-LV (152 +/- 11 vs 156 +/- 9 msec); however, it significantly shortened the times of the strength interval curves obtained for S2 intensities of 2 and 7 mA in the LV, and shortened ERP-RV (139 +/- 10 vs 145 +/- 7 msec, P < 0.01) and the times of the strength interval curve for S2 intensities of 2, 3, and 5 mA in the RV. A significant interaction (MANOVA test) was observed between the ventricle studied and the ganglion stimulated for S2 intensities of 2 and 3 mA, and between the effect of stimulation and the ganglion stimulated for S2 intensities of 3 and 14 mA. To conclude, selective stellectomy prolonged epicardial ventricular refractoriness in both the mid-anterior wall of the RV and the mid-posterolateral wall of the LV; the magnitude of the epicardial excitability variations in both areas was different during selective stellate ganglion stimulation.
authors.affiliation: Department of Medicine, Faculty of Medicine, University of Valencia, Spain.
authors.forename: R
authors.initials: R
authors.lastname: García-Calvo
authors.forename: F J
authors.initials: FJ
authors.lastname: Chorro
authors.forename: M
authors.initials: M
authors.lastname: Sendra
authors.forename: A
authors.initials: A
authors.lastname: Alberola
authors.forename: J
authors.initials: J
authors.lastname: Sanchis
authors.forename: J
authors.initials: J
authors.lastname: Navarro
authors.forename: V
authors.initials: V
authors.lastname: Valentín
authors.forename: V
authors.initials: V
authors.lastname: López-Merino
authors.forename: L
authors.initials: L
authors.lastname: Such
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002304:Cardiac Pacing, Artificial; D004285:Dogs; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D015171:Ganglionectomy; D006321:Heart / Q000294:innervation*; D006329:Heart Conduction System / Q000502:physiology*; D008297:Male; D012032:Refractory Period, Electrophysiological / Q000502:physiology; D013233:Stellate Ganglion / Q000502:physiology*; D016276:Ventricular Function / Q000502:physiology*