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Methods and Results: Tachycardia was induced by electrical stimulation in the right atrium/right ventricle, and the presence of a concealed left free-wall accessory pathway was suggested electrocardiographically (negative P wave in leads I and/or a VL during orthodromic tachycardia) or by earlier atrial activation in the pulmonary artery compared to the high right atrium. Mapping of the mitral annulus was performed during right ventricular pacing or orthodromic tachycardia, and RF energy was applied at the site with the earliest retrograde atrial activation. Ablation was considered effective if tachycardia could not be induced, and if VA dissociation or exclusive retrograde nodal conduction was observed. Ablation was initially successful in 98 of 100 patients. Mean number of radiofrequency pulses were 3.2 ± 2. Mean fluoroscopy time and total procedure time was 14 ± 9 and 107 ± 32 minutes, respectively. There were no complications related to the procedure. At a mean follow-up of 22 ± 13 months, two patients experienced tachycardia recurrence and required a second procedure, which was successful.
Conclusions: Our results suggest that RF catheter ablation of concealed left free-wall accessory pathways can be safely, effectively, and rapidly performed using a simplified two-catheter technique with no need for coronary sinus catheterization. 相似文献
Design A 4-step process was used to develop a brief FFQ for scoring intakes of total fat, fiber, and fruits and vegetables. The resulting questionnaire consisted of 25 food frequency items and 10 supplemental questions. Reproducibility of the questionnaire was determined by comparing responses at the beginning and end of a 4-month interval.
Subjects Study subjects were sixth- and seventh-grade students attending middle schools in rural areas of Virginia and upstate New York. Seventh-grade students participated in the pilot study, and sixth-grade students participated in the reproducibility study. The final version of the FFQ was completed twice by 539 sixth graders. After exclusions for missing and unreliable data, the usable sample size was 415. Boys were somewhat more likely than girls to be excluded for missing data. African-American students comprised 32% of the population.
Statistical analyses performed Each food frequency item was associated with 3 scores—a fat score, a fiber score, and a combined score for the number of servings of fruits and vegetables. Means and standard deviations were determined for nutrient variables, differences between repeat administrations were tested for significance by paired t test, and Pearson correlation coefficients were calculated for nutrients and for individual food items.
Results Correlation coefficients for nutrient scores were 0.58 for fat, 0.49 for fiber, and 0.51 for fruits and vegetables. For individual food items, correlations ranged from 0.24 to 0.59 (mean=0.41).
Applications/conclusions Using a systematic approach to developing a study-specific FFQ for rural adolescents is feasible. Further, the reproducibility of the Goals for Health questionnaire was demonstrated for the 3 nutrient scores it was designed to measure. This developmental approach may be readily adapted to other populations, study designs, and nutrients of interest. The validity of the questionnaire remains to be tested. J Am Diet Assoc. 2001;101:1438-1446. 相似文献