Effects of quiet respiration on left ventricular systolic function by echocardiography / 中华超声影像学杂志

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.