Data highlighting the effects of spinal segmental stimulation of preganglionic sympathetic neurons on the electrophysiology of the rabbit heart

Abstract

This article presents data highlighting the functional selectivity of cardiac preganglionic sympathetic neurons in the rabbit heart. Specifically, the data draw attention to the role of each spinal segmental outflow on cardiac electrophysiology and the influence of each segment on cardiac excitability through investigating markers of arrhythmia such as electrical restitution. This data holds importance for exploring whether the preganglionic sympathetic neurons have functionally distinct pathways to the heart and whether some spinal segmental outflows have a greater potential for arrhythmia generation than others. Discussion of the data can be found in Chauhan et al. (2018) [1].

Functional selectivity of cardiac preganglionic sympathetic neurones in the rabbit heart

“…At each electrode pairing, from T4-T5 to T1-T2, both the right sympathetic and left sympathetic chain augmented HR and LVP (see Fig. 1 in [ 20 ]). The effects were larger at successive rostral levels as more sympathetic preganglionic axons were activated.…”

“…Dromotropic effects were measured during constant pacing with left and right sympathetic chain stimulation at each electrode pairing between T1-T6 (see Fig. 2 in [ 20 ]). A reduction in VA conduction was caused by both left and right sympathetic chain stimulation but the effects were largest following left stimulation.…”

“…Left sympathetic stimulation at T5-T6 decreased the ERP from 147.5 ± 1.4 ms to 131.7 ± 1.7 ms, a change of −8.1 ± 4.4% (see Fig. 3 in [ 20 ]) but there was no effect of right sympathetic at this level. At subsequent levels the ERP was further shortened by stimulation of each sympathetic chain.…”

“…Restitution curves of the MAP duration at corresponding diastolic intervals were plotted, during baseline, left sympathetic stimulation and right sympathetic stimulation (see Fig. 4 in [ 20 ]). At T5-T6, there was a small effect of left sympathetic stimulation, which steepened the maximum slope of restitution by 18.3 ± 1.6% at the base but had no effect at apex (1.4 ± 6.1%) ( Fig.…”