Muscle blood flows by means of hydrogen gas clearance method were measured on hindlimb muscles in sedentary control (nE) and exercised (Ex) spontaneously hypertensive rats (SHR) . SHR and Wistar control rats (WCR) were divided into two groups at 7 weeks of age ; SHRnE, SHREx and WCRnE, WCREx. Exercised rats were bred in cages with rotating wheels capable of running voluntarily for additional 10 weeks. Body weights of exercised groups in both SHR and WCR were lower than those of sedentary controls, whereas food consumptions of exercised rats tended to be more than those of sedentary controls. Ratios of the heart weight to the body weight of SHR and WCR were higher in exercised groups. There was no significant difference in systolic blood pressure obtained by an indirect tail-cuff method between exercised and sedentary control SHR. Resting blood flows in both M. Gastrocnemius and M. Soleus showed lower values in SHR groups than those in WCR groups. Postexercise blood flows at 1 Hz and 5 Hz were higher in exercised groups. These results suggest that peripheral adaptability of blood flow control to the exercise is still normal on hindlimb muscles in SHR.

INTRODUCTIONMyocardial scintigraphy with ¹²³I-15-(p-iodophenyl)-3-methyl pentadecanoic acid (¹²³I-BMIPP) is used to evaluate impaired fatty acid metabolism. B-type natriuretic peptide (BNP), which is secreted by the ventricular myocardium on stretching and/or pressure overload, is a useful cardiac biomarker. This study aimed to evaluate the usefulness of ¹²³I-BMIPP imaging and serum BNP levels in patients with heart failure (HF).

METHODS113 patients with HF were enrolled. There were 68 patients with ischaemic heart disease (IHD) and 22 with overt HF. Cardiac scintigraphy was performed 7 ± 3 days after admission, and heart-to-mediastinum (H/M) count ratios on early and delayed images and washout rates (WR) of ¹²³I-BMIPP were recorded. Serum BNP levels were recorded on the day of ¹²³I-BMIPP imaging. The ejection fraction (EF) was calculated just before cardiac scintigraphy using conventional echocardiography.

RESULTSThe mean BNP level and EF were 282 pg/mL and 47%, respectively, with significant correlation between them. The mean H/M count ratios on early and delayed images were 2.29 and 1.93, respectively, showing significant positive correlations with EF (r = 0.31, p = 0.0006). The WR was significantly correlated with EF (r = -0.36, p < 0.0001) and BNP levels (r = 0.33, p = 0.003), and mean WR was significantly higher in patients with overt HF compared to those without (p < 0.001). Patients with IHD had significantly higher EFs than those with non-IHD (p = 0.03).

CONCLUSIONThe evaluation of impaired myocardial metabolism using ¹²³I-BMIPP scintigraphy and serum BNP levels appears to be useful for the evaluation of severity of HF.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Biomarkers ; metabolism ; Echocardiography ; methods ; Fatty Acids ; metabolism ; Female ; Heart Failure ; blood ; diagnosis ; diagnostic imaging ; Humans ; Iodine Radioisotopes ; Iodobenzenes ; Male ; Middle Aged ; Myocardial Perfusion Imaging ; methods ; Myocardium ; pathology ; Natriuretic Peptide, Brain ; blood ; Time Factors ; Treatment Outcome