Quantitative analysis of parasympathetic innervation of the porcine heart.

Background: Parasympathetic control of the heart is an important component in the regulation of normal cardiac function. However, the anatomic course of parasympathetic innervation of the heart is unclear.

Objective: The purpose of this study was to apply a gross parasympathetic nerve stain technique to reveal the details of the morphology of the cardiac parasympathetic nervous system.

Neural substrate for atrial fibrillation: implications for targeted parasympathetic blockade in the posterior left atrium.

The parasympathetic (P) nervous system is thought to contribute significantly to focal atrial fibrillation (AF). Thus we hypothesized that P nerve fibers [and related muscarinic (M(2)) receptors] are preferentially located in the posterior left atrium (PLA) and that selective cholinergic blockade in the PLA can be successfully performed to alter vagal AF substrate. The PLA, pulmonary veins (PVs), and left atrial appendage (LAA) from six dogs were immunostained for sympathetic (S) nerves, P nerves, and M(2) receptors.

Frequency gradients during two different forms of fibrillation in the canine atria.

Background: Atrial fibrillation (AF) is thought to be sustained by multiple reentrant wavelets or firing foci.

Objective: The aim of this study was to compare the spectral domain characteristics in the left atrium (LA) and right atrium (RA) in two different models of AF.

Methods: Rectangular 8 x 14 electrode arrays were placed on the LA and RA of 14 anesthetized dogs.

The ligament of Marshall as a parasympathetic conduit.

The objective of the study was to investigate the morphology, distribution, and electrophysiological profile of the autonomic fibers that innervate the ligament of Marshall (LOM). Gross anatomical dissections were performed in 10 dogs. Sections of the left vagus nerve, left stellate ganglion, and the LOM were immunostained to identify adrenergic and cholinergic nerves.