Inspiratory muscle strength is a determinant of maximum oxygen consumption in chronic heart failure.

T. P. Chua, S. D. Anker, D. Harrington, A. J. Coats

Department of Cardiac Medicine, Royal Brompton National Heart and Lung Institute, London.

OBJECTIVE--To investigate the significance of respiratory muscle weakness in chronic heart failure and its relation both to maximum oxygen consumption during cardiopulmonary exercise testing and to skeletal muscle (quadriceps) strength. SUBJECTS--Seven healthy men aged 54.9 (SEM 4.3) years and 20 men with chronic heart failure aged 61.4 (1.6) years (P = 0.20) with radionuclide left ventricular ejection fraction of 25.4 (3.0)%. METHODS--Mouth pressures during maximum static inspiratory effort (PImax) at functional residual capacity (FRC) and residual volume (RV) were measured in all subjects and taken as indices of inspiratory muscle strength. Similarly, mouth pressures during maximum static expiratory effort (PEmax) at FRC and total lung capacity (TLC) were taken as indices of expiratory muscle strength. Cardiopulmonary exercise testing was performed in all subjects. All controls and 15 heart failure patients also had their right quadriceps muscle strength measured. RESULTS--There was respiratory muscle weakness in heart failure patients, with reduction of PImax at FRC (59.7) (6.3) v 85.6 (9.6) cm H2O, P = 0.045), PEmax at FRC (94.8 (6.2) v 134.6 (9.1) cm H2O, P = 0.004), and PEmax at TLC (121.7 (8.5) v 160.7 (13) cm H2O, P = 0.028). PImax at RV was also reduced but this did not reach statistical significance (77.3 (6.6) v 89.3 (13) cm H2O, P = 0.44). There was also significant weakness of the right quadriceps muscle (308.5 (22) v 446.2 (28) N, P = 0.001). PImax at both FRC and RV correlated with maximum oxygen consumption (r = 0.59, P = 0.006, and r = 0.45, P = 0.048 respectively) but not PEmax. There was, however, no significant correlation between PImax and right quadriceps strength. CONCLUSIONS--Respiratory muscle weakness is seen in chronic heart failure. The results suggest that inspiratory muscles are important in determining maximum oxygen consumption and exercise tolerance in these patients. The lack of correlation between respiratory and right quadriceps muscle strength further suggests that the magnitude and time course of respiratory and locomotor muscle weakness may differ in individual patients. Treatment aimed at improving the function of the involved muscle groups may alleviate symptoms.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Laoutaris, I. D., Dritsas, A., Adamopoulos, S., Brown, M. D., Cokkinos, D. V. (2008). Effects of Inspiratory Muscle Training in Patients With Chronic Heart Failure. J Am Coll Cardiol 52: 1888-1889 [Full Text]  
• Meyer, F. J., Lossnitzer, D., Kristen, A. V., Schoene, A. M., Kubler, W., Katus, H. A., Borst, M. M. (2005). Respiratory muscle dysfunction in idiopathic pulmonary arterial hypertension. Eur Respir J 25: 125-130 [Abstract] [Full Text]  
• Witte, K K A, Thackray, S D R, Nikitin, N P, Cleland, J G F, Clark, A L (2003). Pattern of ventilation during exercise in chronic heart failure. Heart 89: 610-614 [Abstract] [Full Text]  
• Vibarel, N., Hayot, M., Ledermann, B., Pellenc, P. M., Ramonatxo, M., Prefaut, C. (2002). Effect of aerobic exercise training on inspiratory muscle performance and dyspnoea in patients with chronic heart failure. Eur J Heart Fail 4: 745-751 [Full Text]  
• Coirault, C., Hagege, A., Chemla, D., Fratacci, M.-D., Guerot, C., Lecarpentier, Y. (2001). Angiotensin-Converting Enzyme Inhibitor Therapy Improves Respiratory Muscle Strength in Patients With Heart Failure. Chest 119: 1755-1760 [Abstract] [Full Text]  
• Meyer, F. J., Borst, M. M., Zugck, C., Kirschke, A., Schellberg, D., Kubler, W., Haass, M. (2001). Respiratory Muscle Dysfunction in Congestive Heart Failure : Clinical Correlation and Prognostic Significance. Circulation 103: 2153-2158 [Abstract] [Full Text]  
• Jones, N. L., Killian, K. J. (2000). Exercise Limitation in Health and Disease. NEJM 343: 632-641 [Full Text]  
• Gosker, H. R, Wouters, E. F., van der Vusse, G. J, Schols, A. M. (2000). Skeletal muscle dysfunction in chronic obstructive pulmonary disease and chronic heart failure: underlying mechanisms and therapy perspectives. Am. J. Clin. Nutr. 71: 1033-1047 [Abstract] [Full Text]  
• Clark, A. L., Davies, L. C., Francis, D. P., Coats, A. J.S. (2000). Ventilatory capacity and exercise tolerance in patients with chronic stable heart failure. Eur J Heart Fail 2: 47-51 [Abstract] [Full Text]  
• Lecarpentier, Y., Coirault, C., Langeron, O., Blanc, F. X., Salmeron, S., Attal, P., Riou, B., Chemla, D. (1999). Impaired load dependence of diaphragm relaxation during congestive heart failure in the rabbit. J. Appl. Physiol. 87: 1339-1345 [Abstract] [Full Text]  
• Nanas, S., Nanas, J., Kassiotis, C., Alexopoulos, G., Samakovli, A., Kanakakis, J., Tsolakis, E., Roussos, C. (1999). Respiratory Muscles Performance Is Related to Oxygen Kinetics During Maximal Exercise and Early Recovery in Patients With Congestive Heart Failure. Circulation 100: 503-508 [Abstract] [Full Text]  
• Opasich, C., Ambrosino, N., Felicetti, G., Aquilani, R., Pasini, E., Bergitto, D., Mazza, A., Cobelli, F., Tavazzi, L. (1999). Heart failure-related myopathy. Clinical and pathophysiological insights. Eur Heart J 20: 1191-1200 [Abstract]  
• Daganou, M, Dimopoulou, I, Alivizatos, P A, Tzelepis, G E (1999). Pulmonary function and respiratory muscle strength in chronic heart failure: comparison between ischaemic and idiopathic dilated cardiomyopathy. Heart 81: 618-620 [Abstract] [Full Text]  
• Lecarpentier, Y., Chemla, D., Blanc, F. X., Pourny, J. C., Joseph, T., Riou, B., Coirault, C. (1998). Mechanics, energetics, and crossbridge kinetics of rabbit diaphragm during congestive heart failure. FASEB J. 12: 981-989 [Abstract] [Full Text]