SUMMARYThe autonomic control of submandibular secretion has been investigated in fully weaned, anaesthetized calves 7 weeks after birth. Stimulation of the parasympathetic (chorda-lingual) innervation invariably produced a flow of saliva, the rate of which was frequency dependent over the range 2-8 Hz continuously. Neither the rate of flow nor the output of protein was enhanced by stimulating in bursts at relatively high frequencies. Stimulation of the sympathetic innervation (20 Hz for 1 s at 10 s intervals) alone produced a much slower flow of saliva but with a considerably higher protein content. Stimulation of both together produced no greater flow of saliva than occurred with either alone at the lower frequencies (2 and 4 Hz) but there was a pronounced synergy in respect of the secretion of protein. Following pre-treatment with propranolol (1.0 mg kg-1 I.V.), during on-going chorda-lingual stimulation at 4 Hz, intra-arterial injections of 1 nmol of either vasoactive intestinal peptide (VIP) or pituitary adenylate cyclase activating peptide (PACAP) elicited an increase in the flow and protein output of about the same order of magnitude. Calcitonin gene-related peptide (CGRP) also produced these same effects with roughly half the efficacy of VIP and PACAP but substance P had no detectable effect. It is concluded that VIP, PACAP and possibly CGRP are candidates for neurotransmitters with a role in the control of secretion in this gland.
PurposeThere is controversy and sparse data on whether substrate based techniques in addition to pulmonary vein isolation (PVI) confer benefit in the catheter ablation of persistent atrial fibrillation (AF), especially if long standing. We performed an observational study to assess whether substrate based ablation improved freedom from atrial arrhythmia.Methods286 patients undergoing first ablation procedures for persistent AF with PVI only, PVI plus linear ablation, or PVI plus complex fractionated electrogram (CFAE) and linear ablation were followed. Primary end point was freedom from atrial arrhythmia at one year.ResultsMean duration of pre-procedure time in AF was 28+/-27 months. Freedom from atrial arrhythmia was higher with a PVI+CFAE+lines strategy then for PVI alone (HR 1.56, 95% CI: 1.04-2.34, p=0.032) but was not higher with PVI+lines. Benefit of substrate modification was conferred for pre-procedure times in AF of over 30 months. The occurrence of atrial tachycardia was higher when lines were added to the ablation strategy (HR 0.08, 95% CI: 0.01-0.59, p=0.014). Freedom from atrial arrhythmia at 1 year was higher with lower patient age, use of general anaesthetic (GA), normal or mildly dilated left atrium and decreasing time in AF.ConclusionsIn patients with long standing persistent AF of over 30 months duration, CFAE ablation resulted in improved freedom from atrial arrhythmia. Increased freedom from atrial arrhythmia occurs in patients who are younger and have smaller atria, and with GA procedures. Linear ablation did not improve outcome and resulted in a higher incidence of atrial tachycardia.
S104Heart, Lung and Circulation CSANZ 2013 Abstracts 2013;22:S1-S125 an unsuccessful defibrillation (RVNA 0% vs. RVA 1.7%; p = 0.12). There was also no significant difference in the proportion of patients receiving successful ATP (RVNA 13.2% vs. RVA 17.4%; p = 0.49) or failed ATP (RVNA 2.7% vs. RVA 4.1%; p = 0.25). There was no significant differences in lead impedance (p = 0.99) Conclusion: In this large retrospective study RVNA ICD lead had similar stability and therapy efficacy compared to the traditional RVA position. http://dx.
Introduction: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation of atrial fibrillation. The intervenous ridge (IVR) may be incorporated into ablation strategies to achieve PVI however there are no randomised trials.Methods: We performed a randomised multicentre study to compare the acute procedural outcomes of (1) circumferential antral PVI alone(minimal) versus (2) circumferential antral PVI (CPVI) with IVR ablation to achieve individual PV isolation(maximal). 166 patients (age 59 ± 9 years, AF duration 60months, left atrial size 43.8 ± 6.7 mm) with paroxysmal AF underwent CPVI and were randomised to a minimal or maximal ablation strategy.Results: Pulmonary vein isolation was achieved in all patients. Radiofrequency ablation time was longer in the maximal group (39.7 ± 13.2 vs. 47.6 ± 15.3 min; p = 0.001), with no significant differences between groups regarding procedural or fluoroscopy times. There was no significant difference in acute PV reconnection (37% in minimal and 35% in maximal, p = NS). In the minimal group, 41% of patients required ablation on the IVR to achieve electrical isolation. Minimal group patients requiring IVR ablation had a significantly higher rate of acute PV reconnection compared to minimal patients without IVR ablation (53% vs. 26%; p = 0.01).Conclusion: A maximal ablation strategy is associated with a significant increase in RF time without prolonging procedural or fluoroscopy times, or altering the rate
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