[Study of washout rate in patients with chronic renal failure by dipyridamole 201Tl myocardial scintigraphy--comparison with hypertrophic cardiomyopathy].

Fourteen patients with chronic renal failure (CRF) were studied by dipyridamole 201Tl myocardial scintigraphy. In this study, patients with coronary heart disease were excluded by clinical findings. 201Tl SPECT was performed at 8 min after injection of dipyridamole (0.56 mg/kg) and at a 3-hr delayed interval, and washout rates (WR) were calculated. Because UCG showed left ventricular hypertrophy (thickness; 13 +/ 2 mm) in CRF, the WR values were compared with those of hypertrophic cardiomyopathy (HCM) (n = 9). In CRF, an average WR was 54.2 +/- 6.8% and was significantly higher than that in normal (46.2 +/- 9.1%, p < 0.05, n = 9), though WR in HCM was significantly low (26.9 +/- 11.4%, p < 0.01). Hematocrit value was 24.5 +/- 3.2% in CRF and was significantly lower than that in normal (37.8 +/- 3.6%, p < 0.001). On the other hands, hemoconcentration was observed in HCM (hematocrit; 44.6 +/- 3.6%, p < 0.001). WR in CRF, HCM and normal had significant correlation with hematocrit values (r = -0.796, p < 0.001). These results suggest that anemia or hemoconcentration may affect coronary blood flow and WR, and this should be considered when diagnosing coronary heart disease in CRF or HCM.