Therapeutic effects of noninvasive ventilation on heart failure after acute myocardial infarction in rats / 中华老年医学杂志

ABSTRACT

Objective:To investigate the therapeutic effects of noninvasive ventilation on heart failure(HF)after acute myocardial infarction(AMI)in rats.Methods:A rat model of HF after AMI was established by ligation of the left ventricular branch.Thirty male Wistar rats were randomly divided into three groups according to the random number table method: sham operation group, non-treatment group and noninvasive ventilation treatment group(n=30, each group). Echocardiography was performed on the third day after surgery, and parameters including left atrial diameter(LAD), left ventricular end diastolic diameter(LVEDD), interventricular septum thickness(IVS)and left ventricular ejection fraction(LVEF)were recorded.Serum levels of brain natriuretic peptide 45(BNP45), tumor necrosis factor α(TNF-α), matrix metalloproteinase-2(MMP-2), matrix metalloproteinase-9(MMP-9), and heat-shock protein 70(HSP70)were measured at day 3 after operation by enzyme-linked immunosorbent assays(ELISA). Morphological changes of myocardial tissue were analyzed with hematoxylin-eosin(HE)staining, and cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL).Results:Compared with the non-treatment group, LVEDD decreased[(153.9±8.1)mm/m 2vs.(164.7±10.4)mm/m 2, P<0.05]and LVEF increased[(63.9±7.6) % vs. (54.4±9.4) %, P<0.05]in the noninvasive ventilation group .Compared with the non-treatment group, serum levels of BNP45[(0.65±0.07) % vs. (0.73±0.07) μg/L, P<0.05], TNF-α(361.5±13.1) μg/L vs. (399.1±12.6) μg/L( P<0.05), MMP-2(6 892.8±530.2) μg/L vs. (7 406.0±667.5) μg/L( P<0.05)and MMP-9(143.8±5.9) μg/L vs. (151.1±8.3) μg/L( P<0.05)decreased and levels of HSP70[(1.7±0.1)μg/L vs.(1.4±0.1)μg/L, P<0.05]increased in the noninvasive ventilation group.HE staining showed focal accumulation of neutrophils in the epicardium, loss of muscle striation, disorganized cell polarity and enlarged nuclei in the non-treatment group.Meanwhile, alleviated inflammation, scattered neutrophils between cardiomyocytes and misaligned muscle striation were observed in the noninvasive ventilation group.TUNEL results showed that the myocardial apoptotic index was lower in the noninvasive ventilation group than in the non-treatment group( P<0.05). Conclusions:Noninvasive ventilation can effectively improve heart function, reduce inflammatory response and cardiomyocyte apoptosis in rats with AMI-induced HF and may be an effective treatment for HF after AMI.