[Tl-201 myocardial scintigraphic findings in patients with aortic regurgitation]

To evaluate the myocardial damage associated with aortic regurgitation, thallium-201 myocardial scintigraphy was performed in 13 patients with aortic regurgitation. The data obtained by thallium-201 single photon emission computed tomography were expressed as the extent score, and were compared with data by echocardiography. The results were as follows: 1. In 11 of 13 patients, there were moderate Tl defects in the distribution of bull's eye map, 80% in the apex, 50% in the inferior and lateral regions, 30% in the anterior region and 10% in the septal region. The mean extent score was 22.3 +/- 11.0%. 2. The extent score correlated with the increase in aortic regurgitant flow volume. The extent score according to the Sellers' classifications II, III, and IV was 13.8 +/- 3.7%, 20.1 +/- 9.8% and 31.9 +/- 10.2%, respectively. 3. There was a good negative correlation between the extent score and fractional shortening (r = -0.66, p < 0.01), however, no significant correlation was observed between the extent score and the left ventricular end-diastolic volume. These results suggest that Tl defects in patients with aortic regurgitation are mainly due to myocardial ischemia associated with a decrease in coronary perfusion pressure and that the extent score may sensitively reflect the severity of myocardial damage in cases with aortic regurgitation.