{'fraction_non_alphanumeric': 0.06064356435643564, 'fraction_numerical': 0.04764851485148515, 'mean_word_length': 5.341176470588235, 'pattern_counts': {'":': 0, '<': 5, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Mimicking Preconditioning by Vagal Stimulation. Effects on Ventricular Function in a Chronic Experimental Model

Background: Previous studies have shown that preischemic vagal electrostimulation (pVS) reduces acute myocardial infarctsize, without a significant improvement on ventricular function within the two-hour reperfusion period. It is unknown whichare the long-term effects of pVS on left ventricular function (LVF).Objectives: The aim of this study was to analyze whether the protective effects of brief pVS on acute infarct size improvesLVF in a chronic myocardial ischemia-reperfusion model.Methods: FVB mice were subjected to 45-minutes regional myocardial ischemia followed by 2 hours of reperfusion or 28-daypost-reperfusion follow-up with or without 10-minutes pVS. Infarct size (IS) was measured with 2,3,5-triphenyltetrazoliumchloride, and LVF was assessed by echocardiography and left ventricular catheterization.Results: Preischemic vagal stimulation reduced IS from 66.8±3.2% to 43.2±1.6% (p <0.001) at 2 hours of reperfusion, without afavorable LVF response. At 28 days, the pVS group exhibited LVF improvement, with lower left ventricular end-diastolic pressure(4.44±1 vs. 6.91±1 mmHg in the control group; p<0.05), higher ejection fraction (69.7±2.8% vs. 59.3±3.2; p<0.05), greatershortening fraction (33.4±2.23 vs. 25.8±1.8%; p<0.05) and lower isovolumic relaxation time (25±0.8 ms vs. 30.3±1.2 ms; p<0.05)Conclusions: In a mice model of myocardial ischemia and reperfusion, mimicking ischemic preconditioning by VS improvesthe chronic outcome of infarction, resulting in greater LVF recovery