The Experimental Study Of Echocardiography Evaluation The Function Of Different Left Ventricular Geometry In New Zealand Rabbits With Chronic Intermittent Hypoxia

Objective :To assess the effect of short-term chronic intermittent hypoxia(CIH) on abnormal left ventricular geometry of New Zealand white rabbits and evaluate systolic and diastolic function in different left ventricular geometry at CIH 8 weeks by Echocardiography.Methods:The 65 healthy male New Zealand white rabbits were placed in the CIH cabin, gas control system by introducing nitrogen and oxygen circulation to simulate chronic intermittent hypoxia cabin to CIH, a cycle time of 170 s, so that fluctuations in the cabin oxygen concentration 8% to 21%. we measured forechocardiography through GE-Vivid7 in 0 week to determine the rabbits’ critical value of the left ventricular mass index and the relative wall thickness. Left ventricular geometry was divided into four groups: normal geometry(NG)group, concentric remodeling(CR)set, the concentric hypertrophy(CH)group and the eccentric hypertrophy(EH) group, and measured each group of left ventricular systolic and diastolic function parameters by echocardiography technology,then compared systolic and diastolic function of different left ventricular geometry with LSD-t method.Resluts:1.left ventricular structure parameters: Compared with NG group, Left ventricular end-diastolic phase inner length, Left ventricular length, LV vertical diameter were decreased, Relative wall thickness was increased in CR group; Interventricular septum thickness, left ventricular posterior wall, Left ventricular phase inner length, left atrium anteroposterior length, left ventricular mass index, Relative wall thickness were increased in CH group; Interventricular septum thickness, left ventricular phase inner length, left ventricular length, left atrium anteroposterior diameter, left ventricular mass index were increased, Relative wall thicknessin was decreased in EH group, the differences were statistically significant. In contrast to the CR group, left ventricular mass index were increased in CH group; Left ventricular end-diastolic diameter, Left ventricular diameter,LV vertical diameter, left ventricular mass index were increased, Relative wall thicknessin was decreased in EH set. In contrast to the CH set, left ventricular phase inner length, Left ventricular length, LV vertical diameter were increased, Relative wall thicknessin was decreased in EH group. 2. Left ventricular systolic function parameters: EF in CR, NG, CH,EH groups was successively reduced, IVCT, ET in CR, NG, CH, EHgroups were successively increased, IVS-Sm, LVLW-Sm in NG, CR, CH, EHgroups were successively reduced. 3. Left ventricular diastolic function parameters: MV VE, MV E/A, IVS-Em in NG, EH, CR, CH groups were successively reduced, MV VA in CR, CH, EH, NG groups was successively reduced, IVS-Am, IVRT, DT successively increased in NG, EH, CR, CH groups, IVS-Em/Am in CR, NG, EH, CH groups was successively reduced, E/Em in CR,NG, EH, CH groups were successively increased, Adur T in EH, NG, CR, CH groups was successively increased, Vp in NG, CR, EH, CH group was decresed.Conclusion:1.CIH can leed to abnormal left ventricular geometry of rabbits. 2. CIH can leed to left ventricular systolic and diastolic dysfunction of rabbits, left ventricular diastolic function in which the CH group was heaviest dysfunction, left ventricular systolic function in which the CH group was most damaged.