CAJ | 학술논문

目的：应用超声心动图观察慢性间歇性低氧(CIH)早期新西兰兔左室功能的改变。方法健康雄性新西兰兔24只,置于 CIH 舱内,舱内氧浓度波动于8%~21%,持续6 h/d,6 d/周,共8周。于CIH 第0、1、2、4、6、8周超声心动图观察新西兰兔左室结构和功能,并随机处死1只兔,分离左室,进行 HE染色,观察左室心肌病理改变。结果①左室结构参数：与0周比较,左室后壁厚度及室间隔厚度 CIH 6周时增厚(P <0.05),左室舒张末期内径8周时增大(P <0.05)。②左室收缩功能参数：与0周比较,左室射血分数于2周、4周升高,6周、8周逐渐减低,但仍高于0周(P <0.05),等容收缩时间(IVCT)于1周、2周和4周时缩短(P <0.05)。③左室舒张功能参数：与0周比较,二尖瓣舒张早期峰值流速于 CIH 2周、4周时逐渐升高,6周、8周时逐渐减低,但始终 E/A>1,等容舒张时间(IVRT)于1周时缩短、2周时明显缩短(P <0.05),8周时延长(P <0.05)。④心肌病理改变：CIH 2周、4周时心肌纤维排列轻度紊乱,心肌细胞轻度肿胀,细胞核轻度增大,细胞间质轻度水肿；6周、8周时上述改变加重伴细胞空泡变性,胞浆溶解,细胞间质充血水肿。结论①CIH 早期兔左室收缩和舒张功能代偿,随后出现左室结构的改变；②IVCT 和 IVRT 是反映 CIH 早期兔左室收缩和舒张功能代偿的敏感性指标。
목적：응용초성심동도관찰만성간헐성저양(CIH)조기신서란토좌실공능적개변。방법건강웅성신서란토24지,치우 CIH 창내,창내양농도파동우8%~21%,지속6 h/d,6 d/주,공8주。우CIH 제0、1、2、4、6、8주초성심동도관찰신서란토좌실결구화공능,병수궤처사1지토,분리좌실,진행 HE염색,관찰좌실심기병리개변。결과①좌실결구삼수：여0주비교,좌실후벽후도급실간격후도 CIH 6주시증후(P <0.05),좌실서장말기내경8주시증대(P <0.05)。②좌실수축공능삼수：여0주비교,좌실사혈분수우2주、4주승고,6주、8주축점감저,단잉고우0주(P <0.05),등용수축시간(IVCT)우1주、2주화4주시축단(P <0.05)。③좌실서장공능삼수：여0주비교,이첨판서장조기봉치류속우 CIH 2주、4주시축점승고,6주、8주시축점감저,단시종 E/A>1,등용서장시간(IVRT)우1주시축단、2주시명현축단(P <0.05),8주시연장(P <0.05)。④심기병리개변：CIH 2주、4주시심기섬유배렬경도문란,심기세포경도종창,세포핵경도증대,세포간질경도수종；6주、8주시상술개변가중반세포공포변성,포장용해,세포간질충혈수종。결론①CIH 조기토좌실수축화서장공능대상,수후출현좌실결구적개변；②IVCT 화 IVRT 시반영 CIH 조기토좌실수축화서장공능대상적민감성지표。
Objective To observe the response of left ventricular (LV)function and structure to chronic intermittent hypoxia (CIH)early stage in New Zealand white rabbits by echocardiography.Methods The New Zealand white rabbits were placed in the CIH chamber and exposed to hypoxia for 8 weeks (6 hours/day,6 days/week).The flow of nitrogen and oxygen were regulated into the customized chambers by the gas control delivery system.The fraction of inspired oxygen was changed from 21 % to 8% for 25 s of every 1 70 s.LV structure and function was assessed by echocardiography at CIH 0,1 ,2,4,6,8 weeks and histopathology was done by HE staining simultaneously.Results ①LV structural variables:compared with 0 week,LV posterior wall and interventricular septum thickness thickened at 6 week.LV end diastolic increased at 8 week (P < 0.05 ).② LV systolic function variables:compared with 0 week,LV ejection fraction increased at 2 week and 4 week,decreased at 6 week and 8 week,but it was higher than 0 week (P < 0.05).Isovolumic contraction time (IVCT)decreased at 1 week,2 week,4 week (P <0.05 ).③LV diastolic function variables:compared with 0 week,Peak velocity of early diastolic period increased at 2 week and 4 week,decreased at 6 week and 8 week with E/A>1 .Isovolumic relaxation time (IVRT)decreased at 1 week and 2 week,but increased at 8 week (P < 0.05 ).④ The myocardial pathology showed that myocardial fibers disordered slightly,cardiomyocytes swelled,nuclei increased and intracellular edema when exposed to CIH for 2 week and 4 week.Vacuolar degeneration,edema and congestion were found in intercellular substance at 6 week and 8 week.Conclusions ① LV systolic and diastolic function compensation started at CIH early stage then LV structure abnormality advent later.②IVCT and IVRT are sensitive indicators of LV systolic and diastolic function compensation.