Assessment of left ventricular function during upright treadmill exercise with tantalum 178 and multiwire gamma camera

Abstract

Background: Prior studies with first-pass radionuclide angiography (RNA) during treadmill exercise used a single-crystal (Anger) or multicrystal gamma camera and technetium 99m tracers. Motion correction, when done, used point sources, which limited correction to only plane movement.

Methods and results: We examined the performance of a multiwire gamma camera (MWGC), generator-produced tantalum 178, and a novel method of motion correction during treadmill exercise testing. We studied 100 patients in whom rest and stress gated tomographic myocardial perfusion images were obtained. Eight patients were excluded because of incomplete data. There were 53 men and 39 women aged 52 +/- 12 years. The resting left ventricular (LV) ejection fraction (EF) was 61% +/- 12% by gated single photon emission computed tomography. Stress myocardial perfusion was normal in 83 patients and abnormal in 9 patients. The resting RNA EF in the upright position was 57% +/- 12% (r = 0.52, P = .0001 vs gated EF). At peak exercise, the EF by MWGC was 60% +/- 26% if uncorrected and 69% +/- 13% after motion correction. Among the 80 patients with normal perfusion and normal resting EF by gated single photon emission computed tomography, a normal response to exercise was seen in 52 (63%) without motion correction and 74 (89%) with motion correction (P < .05).

Conclusion: Assessment of LV function is feasible with MWGC. The motion-corrected images significantly improved the results.