To assess the response of the relationship between systolic blood pressure and end-systolic volume to pharmacologic agents with known cardiac effects, we studied 21 patients with known coronary heart disease by means of gated radionuclide angiograms during the infusion of phenylephrine. Each individual was studied during the infusion of phenylephrine twice, once as a control and the second time after the administration of either intravenous dobutamine, topical nitroglycerin ointment, or intravenous propranolol. Eight individuals received 10 μg/kg/min of dobutamine, which reduced resting cardiac volumes ( p < 0.01), raised ejection fraction ( p < 0.01), and shifted the slope (1.38 ± 0.50 to 2.03 ± 0.69, p < 0.01) and pressure intercept (11.1 ± 3.8 to 17.1 ± 4.4 mm Hg, p < 0.05) of the pressure-volume relationship. Five patients received 2 inches of nitroglycerin ointment. Nitroglycerin increased ejection fraction ( p < 0.05) and reduced volumes ( p < 0.05) but did not alter either the slope (1.46 ± 0.68 to 1.49 ± 0.61, p = NS) or intercept (10.6 ± 5.4 to 10.1 ± 6.4 mm Hg, p = NS) of the relationship. Eight patients received 15 mg of intravenous propranolol. Propranolol reduced resting ejection fraction ( p < 0.05), increased volumes ( p < 0.05), and reduced both the slope (1.67 ± 0.58 to 1.51 ± 0.53, p < 0.05) and the intercept (13.8 ± 2.5 to 7.5 ± 2.3 mm Hg, p < 0.05) of the pressure-volume relationship. Thus the systolic blood pressure/end-systolic volume relationship can be assessed from radionuclide angiograms.