超声心动图研究正压通气对犬心功能的影响及其机制  

Influences of positive pressure ventilation on canine heart function and mechanism research by echocardiography

作　　者：王泓[1] 曹铁生[1] 丁康[1] 段云友[1] 刘杰[1] 杨一林[1] 

机构地区：[1]第四军医大学唐都医院超声诊断科,西安710038

出　　处：《中华超声影像学杂志》2005年第1期63-66,共4页Chinese Journal of Ultrasonography

摘　　要：目的观察正压通气时心内瓣口血流速度和左、右心功能的变化,研究正压通气影响血流动力学机制的新理论。方法11条杂种犬,用超声心动图测定正压通气时心内各瓣口的血流速度,右室、左室每搏量,左室容积和射血分数的变化。结果三尖瓣和肺动脉瓣口血流速度正压吸气相减低,呼气相增加;二尖瓣和主动脉瓣口血流速度变化与之相反(P<0.05)。与自主呼吸相比,正压吸气时,右室每搏量减少,左室舒张末和收缩末容积减小,射血分数降低(P<0.05)。结论正压通气使室间隔趋于右移,同时,肺血管床回心血量增加,但与自主呼吸时相比,腔静脉回心血量相对减少,故心功能降低。Objective To observe the effects of positive pressure ventilation(PPV) on hemodynamics and cardiac function of canine and study the mechanism of the influences of PPV on heart function. Methods Pulsed-wave Doppler spectra of cardiac valves were recorded in 11 dogs,which underwent PPV.The stroke volume of left ventricle(LV) and right ventricle(RV),LV volume and ejection fraction were calculated by echocardiography.Results The velocity of blood flow through tricuspid valve and pulmonary valve decreased during positive pressure inspiration,increased during expiration,while the velocity of mitral valve and aortic valve changed reversely.Comparing with spontaneous respiration,RV stroke volume,LV volume of ventricle and ejection fraction decreased during PPV.Conclusions The change of heart function and spectra of valves confirm a new proposition of the mechanism of influences of PPV on heart function: positive pleural pressure was only applied to the left side of ventricular septa and tended to move it rightforward and at the same time,the blood flow from pulmonary vessels returning to left ventricle increased.But comparing with spontaneous respiration,reduced system venous return resulted in decreased cardiac function.

关 键 词：正压通气 血流速度 心功能 超声心动图 血量 射血分数 自主呼吸 容积 降低 气相 

分 类 号：R445.1[医药卫生—影像医学与核医学]