The relation between radionuclide angiography and Doppler echocardiography during contractile changes with infusions...

To define the quantitative relations between radionuclide and Doppler measures of systole during sympathetic activation with epinephrine, 10 young normal men were studied with simultaneous radionuclide angiography and M-mode and Doppler echocardiography during graded infusions of epinephrine (10, 25 and 50 ng/kg/min for 12 minutes each). During a nine-fold increase in circulating levels of epinephrine in arterialized plasma (94 +/- 59 to 879 +/- 310 pg/ml, P less than 0.001), the heart rate increased from 58 +/- 8 to 73 +/- 7 beats/min (P less than 0.01), whereas the mean arterial pressure fell from 82 +/- 3 to 75 +/- 6 mmHg (NS) and end-systolic wall stress decreased from 97 +/- 6 to 67 +/- 10 dynes/sec (P less than 0.01). The ejection fraction as estimated using radionuclide techniques increased from 68 +/- 6 to 83 +/- 6%, the peak ejection rate measured in this way increased from -3.36 +/- 0.3 to -5.10 +/- 0.5 end-diastolic volumes/sec, the ejection fraction as estimated with M-mode echocardiography increased from 66 +/- 5 to 83 +/- 5%, the echocardiographic ventricular dimension shortening increased from -1.78 +/- 0.2 to -2.7 +/- 0.4 sec-1, the peak aortic outflow velocity as measured with Doppler techniques increased from 98 +/- 13 to 147 +/- 25 cm/sec, and the aortic outflow acceleration velocity increased from 11 +/- 3 to 27 +/- 7 m/sec2 (all P less than 0.001). There was a significant correlation between the changes in radionuclide and M-mode estimations of ejection fractions (r = 0.82), between the radionuclide peak ejection rate and M-mode peak dimension shortening (r = 0.80) and between the radionuclide peak ejection rate and the Doppler peak aortic outflow velocity (r = 0.90) (all P less than 0.01). We conclude that corresponding radionuclide and Doppler echocardiographic measurements of systolic function are altered similarly during increased sympathetic activation with epinephrine.