Relationship between Daily Physical Activity and ANS Activity in Patients with CHF MARTIN GARET 1 , FRANCIS DEGACHE 1 , VINCENT PICHOT 1 , DAVID DUVERNEY 1 , FRE ´ DE ´ RIC COSTES 1 , ANTOINE DA COSTA 2 , KARL ISAAZ 2 , JEAN-RENE ´ LACOUR 3 , JEAN-CLAUDE BARTHE ´ LE ´ MY 1 , and FRE ´ DE ´ RIC ROCHE 1 1 Laboratory of Clinical and Exercise Physiology, PPEH Group, Synapse Research Group, University Jean Monnet, CHU Nord, 42055 Saint-Etienne, FRANCE; 2 Cardiology Unit, University Jean Monnet, CHU Nord, 42055 Saint-Etienne, FRANCE; and 3 Laboratory of Clinical and Exercise Physiology, Medical Faculty Lyon-Sud, 69921 Oullins, FRANCE ABSTRACT GARET, M., F. DEGACHE, V. PICHOT, D. DUVERNEY, F. COSTES, A. DA COSTA, K. ISAAZ, J.-R. LACOUR, J.-C. BAR- THE ´ LE ´ MY, and F. ROCHE. Relationship between Daily Physical Activity and ANS Activity in Patients with CHF. Med. Sci. Sports Exerc., Vol. 37, No. 8, pp. 1257–1263, 2005. 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 (P tot 24 h = 78.80*PAEE (J  min -1  kg -1 ) -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. Key Words: CHRONIC HEART FAILURE, HEART RATE VARIABILITY, DAILY ENERGY EXPENDITURE, QUESTIONNAIRE T he promotion of an active lifestyle is one of today’s main issues in public health. Physical activity has proved to be beneficial both in primary and second- ary prevention (1,2,8,12) and a large body of evidence is now available demonstrating the positive role of physical activity on overall health (2,8,19 –21,24,27). In chronic heart failure (CHF), a major goal is to improve daily phys- ical activity levels as daily living is often limited due to symptoms of heart failure. Davies reported that daily limb movement measured by sensors was decreased with the severity of the condition in patients with CHF (9), providing useful information for future cardiac rehabilitation programs or therapeutic intervention. However, this assessment of limb movement encompasses only a single aspect of daily physical activity. There is a need to take also into account its type, its modality and its intensity. A recent physical activity questionnaire adapted to patients with CHF allows a com- plete quantitative and qualitative exploration of daily phys- ical activity through the calculation of daily energy expen- diture (11). Such an approach includes formal rehabilitation training programs within global daily activities allowing a comprehensive dose-response exploration of the impact of daily physical activity in patients with CHF. Autonomic nervous system activity assessed by heart rate variability (HRV) analysis is largely affected by physical activity both during and after performing a physical task. Clinically significant relationships have been drawn be- tween HRV indices and patient prognosis in various popu- lations like the elderly (5), patients with chronic heart failure (4,5,14,15,22), and patients with coronary heart disease (CHD) (16,18). As HRV indices are powerful independent prognostic factors and physical activity is beneficial for survival, both should be correlated. A consistent body of knowledge reports the beneficial effect of formal exercise training performed in rehabilitation programs on autonomic indices and, therefore, prognosis (8,14,15). However, the relationship between daily physical activity, including for- mal training programs, and HRV in patients with CHF has seldom been assessed (3,25,26). Those previous studies focused essentially on the exploration of the confounding effect of physical activity on the interpretation of time- frequency analysis of electrocardiograms as the rhythmical Address for correspondence: Martin Garet, Laboratory of Clinical and Exercise Physiology, PPEH Group, EFCR level 6, CHU Nord, 42055 Saint-Etienne Cedex 2, France; E-mail: martingaret@hotmail.com. Submitted for publication October 2004. Accepted for publication March 2005. 0195-9131/05/3708-1257/0 MEDICINE & SCIENCE IN SPORTS & EXERCISE ® Copyright © 2005 by the American College of Sports Medicine DOI: 10.1249/01.mss.0000174881.68546.ec 1257