ABSTRACT
UNLABELLED: The utility of (99m)Tc-tetrofosmin myocardial SPECT for assessment of pulmonary hypertension and right ventricular thickness has not been well studied. We hypothesized that a ratio of right ventricular activity to left ventricular activity (RV/LV uptake ratio) from SPECT myocardial perfusion images could identify the presence of increased right ventricular wall thickness and elevated systolic pulmonary artery pressure with or without the use of attenuation correction. METHODS: We identified 33 patients with normal findings on stress (99m)Tc-tetrofosmin left ventricular myocardial perfusion imaging who had a complete 2-dimensional echocardiographic study within 3 wk of the SPECT study. Two 6 × 6 pixel regions of interest were placed in the right and left ventricular free walls of both non-attenuation-corrected and attenuation-corrected SPECT images. We examined the correlation of RV/LV uptake ratio with echocardiographic right ventricular free-wall thickness and with pulmonary artery systolic pressure. RESULTS: RV/LV uptake ratio, measured on non-attenuation-corrected images, correlated significantly with both pulmonary artery systolic pressure (r = 0.63 and P < 0.001) and right ventricular wall thickness (r = 0.6 and P < 0.001). Receiver-operating-characteristic analysis of the use of RV/LV uptake ratio to detect significant pulmonary hypertension showed that the area under the curve was 0.78 (95% confidence interval, 0.62-0.95). However, no significant correlation of RV/LV uptake ratio with pulmonary artery systolic pressure or right ventricular wall thickness was found on attenuation-corrected images. CONCLUSION: RV/LV uptake ratio measured on SPECT images can be used to identify patients with high pulmonary artery pressure or right ventricular hypertrophy.
Subject(s)
Hypertension, Pulmonary/diagnostic imaging , Hypertrophy, Right Ventricular/diagnostic imaging , Myocardial Perfusion Imaging/methods , Tomography, Emission-Computed, Single-Photon/methods , Biological Transport , Heart Ventricles/diagnostic imaging , Heart Ventricles/metabolism , Humans , Hypertension, Pulmonary/metabolism , Hypertension, Pulmonary/physiopathology , Hypertrophy, Right Ventricular/metabolism , Hypertrophy, Right Ventricular/physiopathology , Image Processing, Computer-Assisted , Retrospective Studies , Stress, PhysiologicalABSTRACT
STUDY OBJECTIVES: To assess the characteristics of children with type 2 diabetes mellitus and to determine the efficacy and safety of drug therapies for this disease in this population. DESIGN: Retrospective review of medical records. SETTING: Endocrinology specialty clinic at a tertiary teaching children's hospital. PATIENTS: Forty-two children and adolescents with type 2 diabetes examined between January 1996 and December 2001. MEASUREMENTS AND MAIN RESULTS: Demographic information, presenting signs and symptoms, drug history, and laboratory values were obtained in all patients. Presenting signs and symptoms were similar to those seen in adults. Patients were initially treated with metformin (14.3%), sulfonylureas (14.3%), insulin (31.0%), or combination therapy (14.3%). Most drug regimens decreased hemoglobin A 1c (A1C) levels. Overall, patients treated with drugs had a significant decrease in A1C values, from 10.6% +/- 2.7% (mean +/- SD) before treatment to 8.0% +/- 2.0% at 3.2-52.9 months of treatment (p<0.001). Adverse reactions attributed to drugs included hypoglycemia and gastrointestinal distress. CONCLUSION: Drug therapy appears to be effective in lowering A1C values in pediatric patients, although further prospective trials are necessary to determine optimal drug therapy in this population.
