SummaryThis study examined the effects of maintaining euhydration by ingesting fluids with or without carbohydrate on subjective responses of untrained men during prolonged exercise in a hot environment. Six healthy untrained subjects completed 90 min of cycling exercises at 55% maximal oxygen consumption (V O 2 max ) in a hot environment (temperature: 28˚C, humidity: 50%) under three different experimental conditions. During the first trial, subjects did not ingest fluids during exercise (dehydration (DH) trial). In the second and third trials, subjects received mineral water (MW) and hypotonic fluid containing carbohydrate (HF), respectively, in amounts equaling their weight loss in the DH trial. At the end of exercise, the overall rating of perceived exertion (RPE-O) was lower in the MW and HF trials than in the DH trial (14.3 Ϯ 1.0 and 13.7 Ϯ 0.6 vs 17.7 Ϯ 1.0, p Ͻ 0.05, respectively). RPEcardiovascular and RPE-legs were lower at the end of exercise in the HF trial compared with the DH trial. V O 2 , heart rate (HR), and rectal temperature increased during exercise in the three trials. At the end of exercise, the drift in V O 2 was lower in the MW and HF trials than in the DH trial (304 Ϯ 41 and 339 Ϯ 40 vs 458 Ϯ 33 mL, p Ͻ 0.05, respectively). HR at the end of exercise in the HF trial was lower than in the DH trial (158 Ϯ 5 vs 173 Ϯ 7 bpm, p Ͻ 0.05). These results suggest that maintaining euhydration during prolonged exercise in untrained men could attenuate RPE-O and that hypotonic electrolyte-carbohydrate solution could attenuate RPE-legs during exercise. Key Words maintaining euhydration, perceived exertion, prolonged exercise, heat exposure Dehydration, hyperthermia and muscle glycogen depletion are the major determinant factors that induce the reduction of performance during prolonged exercise. Fluid ingestion, especially in a hot environment, attenuates hyperthermia and cardiovascular drift ( 1-4 ), and carbohydrate ingestion reduces the rating of perceived exertion (RPE) during prolonged exercise in endurance-trained subjects ( 5-10 ). However, there is no available data about the physiological and subjective benefits of maintaining body water by ingesting fluid with or without carbohydrate supplementation during prolonged submaximal exercise in untrained healthy subjects.Maintaining euhydration by fluid ingestion attenuates cardiovascular strain induced by both hyperthermia and dehydration during prolonged submaximal exercise in the heat ( 2-4 ). Gonzalez-Alonso et al. suggested that despite a marked cardiovascular drift at the 120 min of exercise, corresponding to ~60% maximal oxygen consumption (V O 2 max ) in a dehydration trial, the increase in V O 2 for exercising and nonexercising muscle of the whole body was similar to a euhydration trial ( 2 ). Additionally, it has been demonstrated that during prolonged exercise an increase in carbohydrate availability by carbohydrate supplementation attenuated RPE ( 8 , 9 , 11 ) while fluid ingestion did not attenuate the RPE ( 4 , 12 ). However, these stu...

Patients (pts) with Kawasaki disease (KD) who develop myocardial infarction are usually asymptomatic before the event; thus, it is crucial that pts at risk be identified. The aim of our study was to assess the ability of myocardial contrast echocardiography (MCE) with harmonic power Doppler imaging (HPDI) to identify perfusion abnormalities in patients with KD at rest and during pharmacological stress imaging with dipyridamole. Results were compared with those of 99mTc-tetrofosmin single-photon emission computed tomography (SPECT) imaging as the clinical reference standard. MCE with HPDI was performed on 20 pts with a history of KD. Images were obtained at baseline and during dipyridamole infusion (0.56mg kg-1) in the apical two-and four-chamber views. Myocardial opacification suitable for the analysis was obtained in all pts (100%). Nine pts with stenotic lesions had a reversible defect after dipyridamole infusion detected by both MCE with HPDI and SPECT, and 3 pts with a history of myocardial infarction had a partially or completely irreversible defect detected by both 2 methods. Three pts. with coronary aneurysm without stenotic lesion, 4 pts with regressed coronary aneurysm, and 2 pts with normal coronary artery in acute phase also had normal perfusion at rest and after pharmacological stress by the 2 methods. A 96% concordance (kappa ϭ 0.87) was obtained when comparing the respective segmental perfusion scores using the two methods at baseline, and an 86% concordance (kappa ϭ 0.81) was obtained at postdipyridamole infusion. After combining baseline and postdipyridamole images, each segment was labeled as having either normal perfusion, irreversible defects, or reversible defects. Using these classifications, concordance for the two methods was 92% (kappa ϭ 0.87). MCE with HPDI is a safe and feasible method by which to detect asymptomatic ischemia due to severe stenotic lesion as a complication of KD. ECHOCARDIOGRAPHIC VIDEODENSITY INDEX OF THE CORONARY ARTERIES IN KAWASAKI DISEASE: A PREDICTOR FOR SUBSEQUENT CORONARY ARTERY ABNORMALITYSuthep Wanitkun, Pongsak Khowsathit, Anant Khositset, Boonchob Pongpanich Department of Pediatrics, Ramathibodi Hospital, Bangkok, Thailand Even IVIG was established as a standard of care for patients with Kawasaki disease, there are still significant numbers of patients who developed coronary artery abnormality (CAA) or were resistant to therapy. Inflammation at the walls of these arteries has been demonstrated earlier during the acute phase. Direct analysis on these sites may reflect the ongoing pathological process. The purpose of our study was to quantitatively analyze the videodensity (VD) of the coronary arterial walls indexed to that of myocardium (videodensity index-VDI). The VDI was evaluated as a potential predictor for subsequent CAA. Patients who fulfilled the diagnostic criteria, ranging in age from 2 months to 9 years, were studied. All the patients ware treated with IVIG 1-2 gm/kg. An HP Sonos 4500 echocardiographic system was used to acquire images of the coron...

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