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[Abstact] Objective To investigate the characteristics of heart rate variability (HRV) of ambulatory electrocardiogram in patients with acute stroke, and evaluate the predictive value of HRV in stroke prognosis. Methods Eighty-three patients acute stroke (study group) and 83 cases of healthy subjects (control group) from October 2016 to October 2017 in Dalian Municipal Central Hospital Affiliated of Dalian Medical University were selected. The 24 h ambulatory electrocardiogram was performed to determine HRV in 2 groups, including standard deviation of NN intervals (SDNN), standard deviation of the 5 min mean cycle lengths (SDANN), root-mean-square successive difference (RMSSD) and percentage value of NN50 count (PNN50). Results The SDNN, SDANN, RMSSD and PNN50 in study group were significantly lower than those in control group: (80.83 ± 10.52) ms vs. (148.11 ± 22.59) ms, (79.98 ± 8.89) ms vs. (129.35 ± 5.34) ms, (19.28 ± 4.25) ms vs. (39.57 ± 2.38) ms and (5.91 ± 2.12) % vs. (19.35 ± 12.15) %, and there were statistical differences (P＜0.05). Among the 83 patients with acute stroke, there were no statistical differences in SDNN, SDANN, RMSSD and PNN50 between ischemic stroke (54 cases) and hemorrhagic stroke (29 cases) (P＞0.05). The SDNN, SDANN, RMSSD and PNN50 in right stroke (43 cases) were significantly lower than those in left stroke (40 cases): (75.18 ± 2.32) ms vs. (88.12 ± 3.58) ms, (73.36 ± 2.18) ms vs. (85.69 ± 7.29) ms, (17.57 ± 1.67) ms vs. (20.58 ± 4.23) ms and (4.39 ± 1.57) % vs. (8.61 ± 1.12) %, and there were statistical differences (P＜0.05). Patients were followed up for 1 year, 24 died and 59 survived. The SDNN, SDANN, RMSSD and PNN50 in dead patients were significantly lower than those in survived patients: (92.35 ± 4.58) ms vs. (154.37 ± 4.65) ms, (76.23 ± 4.03) ms vs. (143.95 ± 4.34) ms, (7.43 ± 2.12) ms vs. (31.65 ± 1.52) ms and (2.35 ± 0.46) % vs. (11.65 ± 0.48) % , and there were statistical differences (P＜0.05). Conclusions The autonomic nervous function of patients with acute stroke is seriously unbalanced, with increased sympathetic excitability and decreased vagus excitability. The decrease of HRV can easily induce cardiac events and seriously affect the prognosis.
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Objective To studytherolesof hypoxia-inducible factor-lalpha( HIF-1α )and vascular endothelial growth factor ( VEGF) in the pathogenesis of hypoxia-induced pulmonary hypertension ( HPH) in neonatal rats.Methods Wistar neonatal rats were assigned into HPH group and the control group using random number table method. Neonatal rats in HPH group were exposed to hypoxia according to HPH model. On day 3 , 7 ,14 and 210f hypoxia,the mean pulmonary artery pressure ( mPAP) , the level of mRNA and protein expression of HIF-1α and VEGF in lung tissue were examined using RT-PCR and Western blot methods respectively. The correlation of HIF-1,VEGF and mPAP were also analyzed. Results The mPAP ( mmHg)in HPH group on day 3 ,7 ,14 and 210f hypoxia were all higher than the control up[8.5±1.5)vs.5.2±1.0),(12.1±2.1)vs.9.6±0.8),(12.9±2.0)vs.(9.1±0.8),(21.0±2. 3) vs. (11. 2 + 1. 6) ,P < 0. 05]. 0n day 3, 7 and 140f hypoxia,the mRNA of HIF-1α in lung tissue of HPH group were significantly higher than the control group ( P <0. 05 ) . On day 70f hypoxia, the HIF-1αprotein in lung tissue of HPH group was significantly higher than the control group(P <0. 05 ) . On day 7 ,14 and 210f hypoxia,the mRNA and protein of VEGF in lung tissue of HPH group were also significantly higher than the control group( P <0. 05 ). Correlation analysis showed that HIF-1α protein were positively correlated with mPAP on day 3 ,7 . 14 and 210f hypoxia in HPH group ( r = 0. 504 .P = 0. 002) , and VEGF protein were positively correlated with mPAP in HPH group on day 7 , 14 and 210f hypoxia( r = 0. 782, P < 0. 001) .Conclusion Both HIF-1α and VEGF play roles in the occurrence and development of HPH in neonatal rats.
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Objective To investigate the influence of brain natrluretic peptide(BNP) in the prognosis of cardiac surgery.Methods Selected 115 cases of pafients with the first cardiac surgery.Their BNP concentration was measured before operation. Observed the relationship between BNP and postoperative atrial fibrillation,mechanical ventilation time,hospital stay,and the mortality of 30 d.Results Whether the patients had hypertension,diabetes,myocardial infarction history,left main stem disease and hemoglobin level or not,showed no definite relationship with BNP (P>0.05).Preoperative lower left ventricular ejection fraction (LVEF)(P=0.002) and European system for cardiac operation risk evaluation [(5±3)scores](P=0.003) were associated with higher BNP level.Postoperative mechanical ventilation time was(15.0±5.4)h,hospital stay was (32±11) d,showed a clear relationship with BNP(P= 0.035,0.001),but postoperative mediastinal infection,atrial fibrillation and mortality of 30 d had no definite relationship with BNP(P>0.05).Conclusion BNP can be used to predict the risk after cardiac surgery.