Objectives
The purpose of this study was to evaluate the changes of left stellate ganglionic nerve activity (SGNA) and left thoracic vagal nerve activity (VNA) after acute myocardial infarction (MI).
Background
Whether MI results in remodeling of extracardiac nerve activity remains unclear.
Methods
We implanted radiotransmitters to record the SGNA, VNA, and electrocardiogram in 9 ambulatory dogs. After baseline monitoring, MI was created by 1-h balloon occlusion of the coronary arteries. The dogs were then continuously monitored for 2 months. Both stellate ganglia were stained for growth-associated protein 43 and synaptophysin. The stellate ganglia from 5 normal dogs were used as control.
Results
MI increased 24-h integrated SGNA from 7.44 ± 7.19 Ln(Vs)/day at baseline to 8.09 ± 7.75 Ln(Vs)/day after the MI (p < 0.05). The 24-h integrated VNA before and after the MI was 5.29 ± 5.04 Ln(Vs)/day and 5.58 ± 5.15 Ln(Vs)/day, respectively (p < 0.05). A significant 24-h circadian variation was noted for the SGNA (p < 0.05) but not the VNA. The SGNA/VNA ratio also showed significant circadian variation. The nerve densities from the left SG were 63,218 ± 34,719 μm2/mm2 and 20,623 ± 4,926 μm2/mm2 for growth-associated protein 43 (p < 0.05) and were 32,116 ± 8,190 μm2/mm2 and 16,326 ± 4,679 μm2/mm2 for synaptophysin (p < 0.05) in MI and control groups, respectively. The right SG also showed increased nerve density after MI (p < 0.05).
Conclusions
MI results in persistent increase in the synaptic density of bilateral stellate ganglia and is associated with increased SGNA and VNA. There is a circadian variation of the SGNA/VNA ratio. These data indicate significant remodeling of the extracardiac autonomic nerve activity and structures after MI.
Reentrant tachycardia can occur in some isolated PVs with both decremental conduction properties and short refractory periods, which suggests that reentry may be one of the mechanisms of PV arrhythmogenicity.
Objective-The purpose of the present study is to test the hypothesis that stellate ganglia ablation can reduce the incidences of atrial arrhythmias in a canine model of pacing-induced heart failure (HF).Background-There is an association between autonomic nerve discharges and atrial arrhythmias (including both bradycardia and tachycardia) in ambulatory dogs with pacing-induced HF.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.