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101.
BACKGROUND: In childhood, late cardiotoxicity is characterized by inappropriately thin wall and consequent increased end-systolic wall stress, but the associations of impaired left ventricular geometry and function occurring under these circumstances need further investigation. HYPOTHESIS: The purpose of this study was to assess anthracycline late effects on the relationships occurring between increased end-systolic stress (ESS) and changes in both M-mode systolic measurements (i.e., endocardial and midwall fractional shortening) and Doppler diastolic indices in the pediatric age. METHODS: The population consisted of 101 children treated with anthracyclines for at least 12 months and 91 healthy children. Using M-mode echocardiography, end-systolic wall stress was calculated as index of afterload, and endocardial and midwall fractional shortening as systolic indices. Doppler transmitral measurements were made as diastolic indices. RESULTS: Patients treated with anthracyclines showed significantly lower relative wall thickness and left ventricular mass index, greater end-systolic wall stress, reduced endocardial and midwall fractional shortening and peak E/A ratio, prolonged deceleration, and isovolumic relaxation times. Direct relationships were found between end-systolic wall stress and both endocardial and midwall shortening. The use of midwall shortening in the relation showed a greater, but not significant increase (from 3 to 6%) in the proportion of patients with depressed systolic function than did endocardial shortening. In the anthracycline group, end-systolic wall stress was also inversely related to relative wall thickness and directly to isovolumic relaxation time. CONCLUSIONS: In childhood, reduced myocardial thickness and increased afterload explain much of systolic and diastolic dysfunction of late anthracycline toxicity. Midwall fractional shortening does not seem to add useful information for identifying subsets of children more prone to the development of heart failure.  相似文献   
102.
The objective of this study was to determine the safety and efficacy of (32)P beta-brachytherapy in totally occlusive in-stent restenosis (ISR). Patients with occlusive ISR were generally excluded from the randomized clinical trials on intracoronary brachytherapy (utilizing either gamma- or beta-sources) that have shown reductions in restenosis rate and need for revascularization procedures. We analyzed short- and long-term effects of (32)P beta-brachytherapy (20 Gy) in 27 patients (28 lesions) with occlusive ISR and 84 (99 lesions) patients with nonocclusive high-risk ISR. The primary outcome measure was frequency of in-lesion angiographic binary restenosis at 7 months. Secondary endpoints were rates of major adverse cardiac events (MACE), target vessel revascularization (TVR), clinically driven TVR, and target lesion revascularization (TLR). (32)P beta-brachytherapy was feasible and safe and provided similar postprocedural angiographic results in the two clinically comparable groups. However, the 7-month binary restenosis rate was higher in the occlusive group, as were the MACE and late total occlusion rates. Multivariate logistic analysis of the overall population indicated occlusive pattern to be the only independent predictor of angiographic restenosis. In both groups, recurrent lesions most often showed a focal pattern with significant reduction of length. Although safe and effective in high-risk ISR, (32)P brachytherapy at 20 Gy does not appear to be sufficient to avoid long-term restenosis in patients with occlusive lesions. Further studies should determine the most suitable source and dosage of brachytherapy for patients with occlusive ISR.  相似文献   
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It has been suggested that the heart plays an active role in the pathogenesis of arterial hypertension. If this is true, there must be early cardiac involvement in young normotensive subjects who develop hypertension later in life and differences in cardiac morphology or function may exist between young normotensive subjects with different risks of developing hypertension. M-mode echocardiography was performed in 51 normotensive male adolescents with at least one hypertensive parent (SHT). These subjects were compared with 55 normotensive sons of normotensive parents (SNT) and with 25 adolescents with borderline hypertension (BH). Control groups were matched for sex and age. The following morphologic parameters were significantly greater in the SHT group than in the SNT group: interventricular septum (0.54 +/- 0.08 vs 0.49 +/- 0.09 cm/m2; p less than 0.01) and posterior wall (0.54 +/- 0.11 vs 0.50 +/- 0.08 cm/m2; p less than 0.05) thickness, left ventricular mass (125.0 +/- 29.1 vs 109.2 +/- 25.4 gm/m2; p less than 0.005), and cross-sectional area (9.9 +/- 1.8 vs 8.9 +/- 1.6 cm2/m2; p less than 0.005). No significant differences between SHT and BH subjects were observed. Excursion of left ventricular posterior wall was significantly higher in the BH group. No differences were observed between SHT and SNT subjects. These data show that the same kinds of changes in cardiac morphology are present in normotensive subjects with a family history of hypertension and in subjects with borderline hypertension, suggesting that cardiac involvement may precede elevation of blood pressure.  相似文献   
106.
In 3858 ambulatory elderly people (age greater than or equal to 65 years) prevalence of hypertension was 67.8%. The hypertensive status was unknown to both the doctor and the patient in 21.4% of cases. More than 90% of known hypertensives were treated, but hypertension could be considered as controlled in less than 30% of them.  相似文献   
107.
OBJECTIVES: This study sought to determine the effect of lipoprotein(a), or Lp(a), levels and apolipoprotein(a), or apo(a), sizes on endothelial function and to explore ethnic differences in their effects. BACKGROUND: Although high levels of Lp(a) have been shown to confer increased cardiovascular risk in Caucasians, its significance in non-Caucasian populations is uncertain. The pathogenic role of the apo(a) component of Lp(a) is also unclear. METHODS: The relationship of Lp(a) levels and apo(a) sizes to endothelial function was examined in a multiethnic cohort of 89 healthy subjects (age 42 +/- 9 years; 50 men, 39 women) free of other cardiac risk factors. Endothelium-dependent, flow-mediated dilation (FMD) and endothelium-independent, nitrate-induced dilation (NTG) were assessed by ultrasound imaging of the brachial artery. RESULTS: Plasma Lp(a) levels were lowest in Caucasians (18.3 +/- 21.1 mg/dl, n = 40); intermediate in Hispanics (30.2 +/- 30.5 mg/dl, n = 21); and highest in African Americans (68.8 +/- 46.0 mg/dl, n = 28). Lipoprotein(a) levels were found to correlate inversely to FMD (r = -0.33, p < 0.005) but not to NTG (r = 0.06, p = 0.60). This association remained significant after adjusting for gender (p = 0.002). In addition, subjects with small apo(a) size of 相似文献   
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