Measurement of the effect of cardiovascular drugs by impedance cardiography in healthy subjects.

Impedance cardiography is a non-invasive electrical method designed to measure cardiac function on a beat-to-beat basis. Impedance changes within a constant high frequency AC-current field are detected by two thoracic electrodes. The potential changes within these two inner electrodes reflect impedance changes due to underlying pulsatile volume displacements. The relevance of the method was shown in investigations with a beta 1,beta 2-mimetic drug, a beta-blocker, an alpha-agonist, an alpha-blocker and a diuretic drug.