STABILITY OF NUCLEAR PROBE DERIVED PRESSURE-VOLUME LOOP MEASUREMENTS

The nuclear probe (NP) is a single-crystal nonimaging nuclear detector which provides accurate measurements of relative left ventricular vol ume and ejection fraction (EF). The purpose of this study was to asses s the stability of end-diastolic volume (EDV), end-systolic volume (ES V), and the end-systolic pressure-volume relationship (ESPVR) during r epeated pressure-volume loop measurements and after moving and reposit ioning the probe. Eleven patients had an equilibrium radionuclide angi ogram performed followed by cardiac catheterization. EDV, ESV, and ESP VR were calculated from heart rate, cardiac output, and NP-derived EF. These measurements were repeated without moving the probe and after m oving and repositioning it over the patients' chests. There was a good correlation between equilibrium radionuclide angiogram EF and probe E F (r = 0.86). There were no significant changes in EDV, ESV, or ESPVR during the repeated measurements or after repositioning the probe. It is concluded that the NP can provide accurate and reproducible measure ments of EDV, ESV, and ESPVR for cardiac catheterization laboratory in terventional studies.