Instantaneous measurement of left and right ventricular stroke volume and pressure-volume relationships with an impedance catheter.

摘要: The feasibility of using continuous on-line recording intraventricular electrical impedance to measure ventricular stroke volume was assessed in 12 patients at cardiac catheterization with a multielectrode catheter and 1.3 kHz measuring current 4 microA. Stroke volumes determined by were compared the thermodilution technique 10 correlated an r value .95. Directional changes recordings throughout cycle also curves obtained from six radionuclide ventriculography, all instances agreement between two excellent. For patients, measurements showed beat-by-beat decrease Valsalva maneuver administration amyl nitrite, as well immediate increase contraction following extra-systolic beat. Similar directional recorded both left right ventricles. Left pressure-volume relationships simultaneous pressure signals determine if can be used clinically. Pressure-volume diagrams subsequently plotted, for these characteristic isovolumetric relaxation phases typical ejection filling periods. Moreover, sequential constructed during nitrite revealed linear end-systolic relationship.(ABSTRACT TRUNCATED AT 250 WORDS)