transthoracic impedances 《英文msh詞典》Transthoracic Impedances ; [入口詞] Transthoracic Impedances ; [主題詞] Cardiography,Impedance ; [英文釋義] A type of impedance plethysmography in which bioelectrical impedance is measured between electrodes positioned around the neck and around the lower thorax. It is used principally to calculate stroke volume and cardiac volume,but it is also related to myocardial contractility,thoracic fluid content,and circulation to the extremities.