Assessment of left ventricular function using a conductance catheter in the human heart.

To validate the usefulness of the conductance catheter in the clinical setting, we first studied the accuracy of human left ventricular (LV) volume measured by conductance catheter in comparison with LV volume measured by biplane angiography in 19 patients with heart disease. Secondly, we made a comparison of end-systolic pressure volume relation (ESPVR) and preload recruitable stroke work (PRSW) relation in 60 patients with heart disease. Thirdly, we studied the myocardial oxygen consumption (VO2)-pressure volume area (PVA) relation to assess contractile efficiency in 22 patients with heart disease. There was a good correlation between the corrected conductance volume (Vcc) and the angiographic volume (V angio) (Vcc = 0.94 Vangio + 5.4, r = 0.94, P less than 0.001). Two relations, ESPVR and PRSW, were well described by straight lines with high correlation coefficients. However, PRSW was a more linear contractile index than ESPVR. The reciprocal of the slope of the VO2-PVA relation was approximately 40% in the control contractile state. We conclude that the conductance catheter accurately measures LV volumes and facilitates the assessment of ESPVR, PRSW and contractile efficiency in human LV.