BACKGROUND : Norm-referenced equations to predict the 6-minute walk distance (6MWD) in healthy Japanese subjects have not been established. The current study aimed to determine the reference values for 6MWD in healthy Japanese adults.
METHODS : Ninety-seven healthy Japanese men and women aged 40-79 years were recruited from Kyoto city using posters and flyers. Measurements of 6MWD were performed twice on an indoor 30 m track with 20 minutes rest between the two tests. Before performing the tests, age, gender, height, body weight, waist circumference, a questionnaire for health status, spirometry, and a 12-lead electrocardiogram were recorded. The 6MWD was measured following guidelines published in 2002 by the American Thoracic Society.
RESULTS : The mean age of the study subjects was 57.0±9.4, and 63 of the 97 subjects were female. The mean 6MWD for all subjects was 672±83 m, with a range of 483-903 m. The 6MWD is significantly correlated with age, height, waist circumference, forced vital capacity (FVC), and forced expiratory volume in one second (FEV₁). A multiple linear model showed age, waist circumference, and FVC were significantly associated with 6MWD and the model explained 35% of the variability in 6MWD. When FVC was replaced by height, the regression model also explained 32% of the variation. The measured 6MWD of Japanese subjects was similar to the predicted 6MWD using the equations derived from Caucasian subjects.
CONCLUSIONS : The 6MWD was affected to a substantial degree by age, waist circumference, height, and FVC in healthy Japanese adults.

We present an unusual case of a delayed right ventricular perforation by a single standard-caliber implantable cardioverter-defibrillator lead, which manifested 14 days after implantation. Multidetector computed tomography could clearly display the lead perforation, and allow for identification of the associated sequelae such as pericardial effusion and planning the lead extraction strategy.
Defibrillators, Implantable ; Multidetector Computed Tomography ; Pericardial Effusion