Stability of Nuclear Probe Derived Pressure-Volume Loop Measurements

Abstract

The nuclear probe (NP) is a single-crystal nonimaging nuclear detector which provides accurate measurements of relative left ventricular volume and ejection fraction (EF). The purpose of this study was to assess the stability of enddiastolic volume (EDV), end-systolic volume (ESV), and the end-systolic pressure- volume relationship (ESPVR) during repeated pressure-volume loop measurements and after moving and repositioning the probe. Eleven patients had an equilibrium radionuclide angiogram performed followed by cardiac catheterization. EDV, ESV, and ESPVR were calculated from heart rate, cardiac output, and NP-derived EF. These measurements were repeated without moving the probe and after moving and repositioning it over the patients’ chests. There was a good correlation between equilibrium radionuclide angiogram EF and probe EF (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 measurements of EDV, ESV, and ESPVR for cardiac catheterization laboratory interventional studies.