【摘要】 目的观察平静呼吸时胸压变化对左、右心室前后径及左室收缩功能的影响,进一步证实呼吸影响血流动力学机制新假说。方法20名健康志愿者,用Sequoia512彩色超声同步记录呼吸曲线。启动二维及M-型超声心动图记录右室前壁、室间隔及左室后壁活动曲线,测量舒张末期室间隔左室面随呼吸摆动幅度,分别测量呼气和吸气时右室前壁、室间隔、左室后壁的收缩幅度及左、右心室舒张期和收缩期内径,计算左室短轴缩短率、每搏输出量及射血分数,并计算上述指标随呼吸的变化率。结果平静呼吸时,室间隔吸气时摆向左室侧,呼气时摆向右室侧,室间隔随呼吸左右摆动幅度为(1.76±0.50)cm;右室舒张期前后径吸气时较呼气时明显增大,左室变化相反;室间隔及左室后壁收缩期运动幅度及左室每搏输出量呼气时较吸气明显增加,而射血分数及短轴缩短率在呼气和吸气间无明显差别。结论呼吸性胸压变化最终作用到了室间隔上,使左、右室内径及收缩功能发生交替性变化。更多还原

【Abstract】 Objective To investigate the effects of quiet respiratory intrathoracic pressure changes on ventricular dimensions and left ventricular systolic function,and to further verify our newly proposed hypothesis of the mechanism of respiratory effects on hemodynamics.Methods Twenty healthy volunteers aged 18 to 40 years average(24±7) years were included.The respiratory curve and electrocardiogram were simultaneously recorded.The interventricular septum movement,ventricular dimensions and ventricular systolic excursions were recorded by two-dimensional and M-mode echocardiography during quiet respiration.The respiratory variations of the above parameters were derived,and the parameters for assessing ventricular systolic function were calculated.Results With quiet respiration,the interventricular septum moved towards the left ventricle on inspiration,and then towards the right ventricle on expiration.The right ventricular diastolic dimension increased significantly on inspiration compared with those on expiration.The opposite changes occurred with left ventricular diastolic dimensions.The left ventricular posterior wall systolic excursion and the left ventricular stroke volume significantly increased during expiration compared with those during inspiration.No significant differences were found in left ventricular ejection fraction and fractional shortening between inspiration and expiration.Conclusions The respiratory intrathoracic pressure change is one of the factors influencing the reciprocal changes of the left and right ventricular parameters related to ventricular dimensions and systolic function.更多还原