Renal sympathetic denervation suppresses atrial fibrillation induced by acute atrial ischemia/infarction through inhibition of cardiac sympathetic activity. (15th January 2016) - Zhou, Qina
Abstract: Objective: This study aims to explore the effects of renal sympathetic denervation (RSD) on atrial fibrillation (AF) inducibility and sympathetic activity induced by acute atrial ischemia/infarction. Methods: Acute ischemia/infarction was induced in 12 beagle dogs by ligating coronary arteries that supply the atria. Six dogs in the sham-RSD group did not undergo RSD, and six dogs without coronary artery ligation served as controls. AF induction rate, sympathetic discharge, catecholamine concentration and densities of tyrosine hydroxylase-positive nerves were measured. Results: Acute atrial ischemia/infarction resulted in a significant increase of AF induction rate, which was decreased by RSD compared to controls ( P < 0.05). The root-mean-square peak value, peak area and number of sympathetic discharges were significantly augmented by atrial ischemia relative to the baseline and control ( P < 0.05). The number of sympathetic discharges was significantly reduced in the RSD group, compared to the control and sham-RSD groups ( P < 0.05). Norepinephrine and epinephrine concentrations in the atria, ventricle and kidney were elevated by atrial ischemia/infarction, but were reduced by RSD ( P < 0.05). Conclusions: Sympathetic hyperactivity was associated with pacing-induced AF after acute atrial ischemia/infarction. RSD has the potential to reduce the incidence of new-onset AF after acute atrial ischemia/infarction. The inhibition of cardiac sympathetic activity by RSD may be one of the major underlying mechanisms for the marked reduction of AF inducibility.