Relationship between plasma norepinephrine at peak exercise and 123I-MIBG imaging of the heart and lower limbs in heart failure.

BACKGROUND: Past studies suggested that plasma norepinephrine during exercise originates in sympathetic nerve endings and that the main origin differs among pathophysiological conditions. AIMS: This study investigated the most important site of sympathetic terminals as an origin of plasma norepinephrine during exercise in patients with heart failure using (123)I- metaiodobenzylguanidine (MIBG) scintigraphy. METHODS AND RESULTS: Twenty patients with organic heart disease underwent exercise testing and (123)I-MIBG scintigraphy. Systemic (123)I-MIBG uptake was measured 4 hours after (123)I-MIBG injection, and the heart-to-brain (H/B) and lower limb-to-brain ratios (L/B) were calculated. Plasma norepinephrine concentration was measured at rest and at peak exercise. Subjects were divided into two groups: those with preserved left ventricular ejection fraction (LVEF> or =45%, n=8) and those with reduced LVEF (<45%, n=12). Plasma norepinephrine at rest did not correlate with H/B or L/B. In the preserved LVEF group, plasma norepinephrine at peak exercise was correlated with H/B (r=0.722), but not with L/B. In the reduced LVEF group, the norepinephrine response to peak exercise correlated with L/B (r=0.642), but not with H/B. CONCLUSION: The present findings suggest that norepinephrine concentration is regulated by sympathetic terminal function of working muscles in patients with impaired LVEF and by that of the heart in patients with preserved LVEF.

Clinical features of hematological disorders caused by copper deficiency during long-term enteral nutrition.

OBJECTIVE: Copper deficiency has been reported to cause hematological disorders. However, its clinical and hematological characteristics are not fully understood. Therefore, we investigated bedridden patients suffering from copper deficiency and tried to clarify the clinical features of hematological disorders caused by this condition. PATIENTS AND METHODS: Five patients with typical copper deficiency who had been dependent upon enteral nutrition for a long period of time due to various diseases were investigated. We measured hematological parameters and observed the response to copper supplementation therapy and the recovery process of hematological disorders. RESULTS: Their mean age was 82.6+/-10.4 years and the mean duration of enteral nutrition was 16.4+/-5.2 months. Their serum copper concentration was extremely decreased (range, 3 to 8 microg/dl). All five patients had anemia and neutropenia. On the other hand, platelet count remained within the normal range. After copper supplementation therapy, hemoglobin concentration increased from 6.8+/-0.7 g/dl to 9.9+/-0.7 g/dl within a few months (p<0.01). Neutrophil count also increased from 750+/-370/microl to 3,690+/-1,210/microl in a few weeks (p<0.01). Mean corpuscular volume (MCV) decreased from 94.3+/-7.3 fl to 86.0+/-4.8 fl (p<0.05). Elevated serum ferritin and erythropoietin (EPO) levels were normalized after the improvement of anemia. CONCLUSION: Bicytopenia (anemia and neutropenia) with normal platelet count is a feature of hematological disorders caused by copper deficiency. MCV tends to indicate macrocytic anemia. Serum ferritin and EPO levels are elevated. These hematological abnormalities are improved within a few months after copper supplementation therapy.