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Purpose: This study assessed the relationship between the Minnesota Living With Heart Failure Questionnaire (MLWHFQ) and key ventilatory expired gas measures during a symptom-limited exercise test in the heart failure (HF) population. Specifically, is there evidence to indicate that perceived quality of life (QOL) influences exercise performance independent of physiologic function in the HF population?, Methods: Thirty-one subjects (21 male/10 female), diagnosed with compensated HF, underwent exercise testing and completed the MLWHFQ. Mean age and left ventricular ejection fraction were 52.8 years and 27.2%, respectively. Partial correlation, controlling for age and sex, assessed the relationship between MLWHFQ (overall and subscores) and key ventilatory expired gas measures. Intraclass correlation coefficient (ICC) analysis was used to determine reliability of the MLWHFQ., Results: MLWHQ overall score (mean = 38.9, median = 36.0), physical subscore (mean = 14.8, median = 16.0), and psychosocial/symptomatology subscore (mean = 24.1, median = 19.0), were significantly correlated (P < or =.05) with peak oxygen consumption (VO2). The relationship between MLWHFQ and the minute ventilation-carbon dioxide production (VE/VCO2) slope was, however, not significant. ICC analysis revealed high reliability (0.95) for the MLWHFQ., Conclusions: The MLWHFQ demonstrates a significant relationship with peak VO2, a measure whose validity is dependent upon subject effort. VE/VCO2 slope, which is independent of subject effort and therefore potentially a better predictor of true physiologic function, does not appear to have a relationship with perceived QOL. These findings have implications for how the MLWHFQ is assessed, related to an exercise test, and used during clinical practice.

Study Objective: Erroneous time documentation of emergency treatment caused by the variation in the accuracy of timepieces has profound medical, medicolegal, and research consequences. The purpose of this study was to confirm the variation of critical timepiece settings in an urban emergency care system noted in previous studies and to implement and monitor the results of a prospective program to improve time synchronization., Methods: Timepieces (n=393) used by firefighters, paramedics, and emergency physicians and nurses were randomly sampled immediately before and at two time intervals (1 and 4 months) after attempted synchronization to the US atomic clock standard. The setting on each timepiece was compared with the atomic clock. From the data, a mathematical simulation estimated the number of time-related documentation errors that would occur in 2,500 simulated cardiac arrest cases using timepieces with accuracy similar to those found in the EMS system before and after attempted synchronization., Results: Before attempted synchronization, the timepieces had a mean error of 2.0 (95% confidence interval 1.8 to 2.3) minutes. One month after attempted synchronization, the mean error decreased significantly to .9 (.8 to 1.1) minute. However, it increased to 1.7 (1.5 to 1.9) minutes within 4 months. Mathematical simulation before attempted synchronization predicted that 93% of cardiac arrest cases would contain a documentation error of 2 minutes or more and that 41% of cases would contain a documentation error of 5 minutes or more. Attempted synchronization cut the 2-minute documentation error rate in half and reduced the 5-minute documentation error rate by three fourths. However, the error rates were predicted to return to baseline 4 months after attempted synchronization., Conclusion: Emergency medical timepieces are often inaccurate, making it difficult to reconstruct events for medical, medicolegal, or research purposes. Community synchronization of timepieces to the atomic clock can reduce the problem significantly, but the effects of a one-time attempted synchronization event are short-lived. [Ornato JP, Doctor ML, Harbour LF, Peberdy MA, Overton J, Racht EM, Zauhar WG, Smith AP, Ryan KA: Synchronization of time-pieces to the atomic clock in an urban emergency medical services system. Ann Emerg Med April 1998;31:483-487.].