Quantitative assessment of daily physical activity levels in patients with chronic heart failure by measuring energy expenditure--effects of converting enzyme inhibitor therapy

Relationship between Daily Physical Activity and ANS Activity in Patients with CHF

PURPOSE

Heart rate variability (HRV) indices are powerful independent prognostic factors of cardiovascular events and all cause mortality in patients with chronic heart failure (CHF). This study evaluates the influence of lifestyle on HRV in CHF patients.

METHODS

Thirty-nine CHF patients (33 men, ischemic/dilated cardiomyopathy (18/21), 52.4 +/- 11.2 yr, NYHA I to III, LVEF 33.4 +/- 5.1%) filled out a physical activity questionnaire providing an individual complete qualitative and quantitative picture of their physical activity and daily energy expenditure (PAEE/DEE) corrected for age, weight, severity of the condition and autonomy. Frequency and time domain indices of HRV were calculated from ECG Holter recordings on a typical weekday. Nighttime indices were calculated in order to avoid the confounding factor of physical activity that might alter 24-h frequency analysis of HRV.

RESULTS

DEE was significantly different between classes I and II and classes I and III (P = 0.01 both) patients. Time spent in activities above 3 METs decreased significantly with the severity of the condition. Global and parasympathetic indices of 24-h HRV analysis were correlated to DEE and PAEE (Ptot24h = 78.80*PAEE (J x min x kg) -1061.80, R = 0.72, P < 0.0001). Multiple regression analysis revealed that PAEE was the sole independent factor on established HRV prognostic indices (P < 0.05) and especially within PAEE dimensions, only activities above 3 METs were correlated with established prognostic HRV indices (P < 0.05).

CONCLUSION

These results indicate that rather than total DEE, moderate to intensive physical activity may counteract the decline in HRV with chronic heart disease. This may be linked to longer time spent in higher intensity activities, and not to total activity time.

Level of Activities Associated With Mobility During Everyday Life in Patients With Chronic Congestive Heart Failure as Measured With an "Activity Monitor"

Background and Purpose. Because of dyspnea and fatigue, patients with congestive heart failure (CHF) may be restricted in the performance of normal everyday activities. The aim of this study was to obtain a preliminary indication of the level of activities associated with mobility during everyday life and between-day variance in activities in patients with mild to moderate CHF as measured with an “Activity Monitor.” Subjects and Methods. The “Activity Monitor” is based on long-term (&gt;24 hours) ambulatory monitoring of signals from accelerometers fixed to the subject's body during everyday activities with the aim of assessing the level of activities associated with mobility. Measurements were obtained over 3 days from 5 male subjects with CHF (mean age=64 years, SD=5, range=59–72) and over 2 days from 5 matched comparison subjects (mean age=65 years, SD=4, range=61–71). Results. Mean duration of movement-related activities (walking, cycling, or general movement) (expressed as a percentage of the duration of the measurement day) was lower in the subjects with CHF (X̄=3.9, SD=1.5, range=2.2–6.7) than in the comparison subjects (X̄=11.3, SD=3.0, range=6.6–14.1). In the patients, between-day variance was smaller for different weekdays (eg, Monday versus Tuesday) than for similar weekdays (eg, 2 Mondays) (1.11% and 7.28%, respectively). Discussion and Conclusion. The results show how activities associated with mobility during everyday life may be restricted in people with CHF.

Simple methods of assessing physical activity in patients with chronic heart failure

This article reviews simple, noninvasive ways to assess physical activity in patients with chronic heart failure. Six- or 9-minute walk tests appear to be useful not only for selecting patients with relatively advanced heart failure but also as prognostic screening tests. The Master-Borg test (Master's two-step testing and 10-point Borg scale) is useful for assessing symptoms during exercise. Weekly pedometer counts show that the level of activity in patients with heart failure is dramatically less than in healthy controls. Physical activity can be determined directly by an ambulatory calorie counter that measures step scores and energy expenditure using specific accelerometers. Careful clinical interviewing regarding symptoms, together with submaximal exercise testing and use of motion sensors, are recommended as useful, simple, noninvasive alternatives for assessing physical activity in this patient population. (c)2000 by CHF, Inc.

Oxygen uptake and its relation to physical activity and other coronary risk factors in asymptomatic middle-aged Japanese

PURPOSE

Low physical activity is considered to be an important risk factor for atherosclerotic coronary artery disease. However, few data are reported on the Japanese general population. The authors have studied whether oxygen uptake in physical fitness evaluation is a quantitative index for physical activity and whether or not it has a relation to coronary risk factors.

METHODS

Five hundred thirteen asymptomatic Japanese (40-64 years of age, 282 males and 231 females) were tested on a cycle ergometer for measurement of peak oxygen uptake (peak VO2) and oxygen uptake at anaerobic threshold (VO2AT). Physical activity was estimated by pedometer score. Data for oxygen uptake were adjusted by age or by age and body mass index (BMI), then its relationship to the following risk factors was investigated: physical activity, BMI, blood pressure, total cholesterol, HDL and LDL cholesterol, fasting blood glucose, and triglycerides.

RESULTS

Subjects in the highest peak VO2 quartile walked significantly more than those in the lowest quartile in both males and females. Those in the highest quartile showed lower BMI, lower blood pressure, lower triglyceride, and higher HDL cholesterol. The same relationship was observed for VO2AT.

CONCLUSIONS

Higher fitness level determined by peak VO2 or VO2AT is related to higher physical activity and lower coronary risk factors in the asymptomatic middle-aged Japanese. These data provide support for exercise prescription in the primary prevention of coronary heart disease in Japan.