Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Abstract: In this investigation, determinations of peak diastolic filling rate (PDFR) and ejection fraction (EF) by two distinct nuclear techniques--gated radionuclide angiography (RNA) and nuclear cardiac probe (NCP)--were compared with contrast ventriculography in 44 patients with coronary artery disease (CAD). In addition, PDFR was tested as a potential index of the severity of disease. Good agreement in PDFR was found between NCP and contrast ventriculography (r = 0.83, p less than 0.001), but there was poor correlation between RNA and contrast ventriculography. Ejection fraction measured by either RNA or NCP correlated well with contrast ventriculography (r = 0.96 and r = 0.73, respectively). A positive correlation was found between PDFR and the EF measured by the NCP (r = 0.79) and by contrast ventriculography (r = 0.64), but poor correlation was found between these parameters by RNA. Patients with multivessel CAD had lower PDFR than patients with single vessel disease when studied by the NCP (1.6 +/- 0.4 versus 2.5 versus 0.6 EDV/sec [mean +/- s.d.], p less than 0.0001), but not by RNA. Thus, compared with contrast ventriculography, determination of PDFR is more accurate by NCP than by RNA. Furthermore, the PDFR measured by NCP, but not by RNA, may be a potentially useful index of the extent of CAD.
Comparison of left ventricular diastolic function as determined by nuclear cardiac probe, radionuclide angiography, and contrast cineangiography.