This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nanas, S. Articles by Roussos, C. Search for Related Content PubMed PubMed Citation Articles by Nanas, S. Articles by Roussos, C.

(Circulation. 1999;100:503-508.)
© 1999 American Heart Association, Inc.

Clinical Investigation and Reports

Respiratory Muscles Performance Is Related to Oxygen Kinetics During Maximal Exercise and Early Recovery in Patients With Congestive Heart Failure

Serafim Nanas, MD; John Nanas, MD, PhD; Christos Kassiotis, MD; George Alexopoulos, MD; Anastasia Samakovli, MD; John Kanakakis, MD; Elias Tsolakis, MD; Charis Roussos, MD, MSc, PhD, MRS, FRCP(C)

From the Departments of Pulmonary and Critical Care Medicine (S.N., C.K., A.S., C.R.) and Clinical Therapeutics (J.N., G.A., J.K., E.T.), National and Kapodestrian University, Athens, Hellas, Greece.

Correspondence to Serafim Nanas, MD, Pulmonary and Critical Care Department, Evgenidio Hospital, Papadiamantopoulou 20, Athens 11528, Hellas, Greece.

Background—Dyspnea and fatigue are the main causes of exercise limitation in chronic heart failure (CHF) patients, whose peak inspiratory (Pi_max) and expiratory pressures (Pe_max) are often reduced. The aim of this study was to examine the relationship between respiratory muscle performance and oxygen kinetics.

Methods and Results—A total of 55 patients (NYHA class I to III) and 11 healthy subjects underwent cardiopulmonary exercise tests (CPET) on a treadmill. In 45 of the 55 patients (group I) and in healthy subjects (group II), pulmonary function tests, Pi_max, and Pe_max were measured before and 10 minutes after exercise, and oxygen kinetics were monitored throughout and during early recovery from CPET. The first degree slope of oxygen consumption (O₂) decline during early recovery (O₂/t-slope) and O₂ half-time (T_1/2) were calculated. In 10 of the 55 CHF patients (group III), the measurements of Pi_max were repeated 2, 5, and 10 minutes after CPET. A >10% reduction in Pi_max after CPET (subgroup IA) was measured in 11 of 45 patients. In contrast, 34 of 45 CHF patients (subgroup IB) and all control subjects (group II) had Pi_max>90% of baseline value after CPET. Subgroup IA patients had significantly lower peak O₂ (13.5±2.1 versus 17.8±5.6 mL · kg^-1 · min^-1; P<0.001), lower anaerobic thresholds (10.1±2.4 versus 13.6±4.6 mL · kg^-1 · min^-1; P=0.003) and lower O₂/t-slopes (0.365±0.126 versus 0.519±0.227 L · min^-1 · min^-1; P=0.008) than subgroup IB patients.

Conclusions—The reduction of Pi_max after exercise is associated with prolonged early recovery of oxygen kinetics, which may explain, in part, the role played by respiratory muscles in exercise intolerance in CHF patients.

Key Words: respiratory muscles • heart failure • oxygen • exercise test

This article has been cited by other articles:

				S. N. Nanas, J. N. Nanas, D. Ch. Sakellariou, S. K. Dimopoulos, S. G. Drakos, S. G. Kapsimalakou, C. A. Mpatziou, O. G. Papazachou, A. S. Dalianis, M. I. Anastasiou-Nana, et al. VE/VCO2 slope is associated with abnormal resting haemodynamics and is a predictor of long-term survival in chronic heart failure Eur J Heart Fail, June 1, 2006; 8(4): 420 - 427. [Abstract] [Full Text] [PDF]

				P. Dall'Ago, G. R.S. Chiappa, H. Guths, R. Stein, and J. P. Ribeiro Inspiratory Muscle Training in Patients With Heart Failure and Inspiratory Muscle Weakness: A Randomized Trial J. Am. Coll. Cardiol., February 21, 2006; 47(4): 757 - 763. [Abstract] [Full Text] [PDF]

				F. Laghi and M. J. Tobin Disorders of the Respiratory Muscles Am. J. Respir. Crit. Care Med., July 1, 2003; 168(1): 10 - 48. [Abstract] [Full Text] [PDF]

				S. Nanas, J. Nanas, O. Papazachou, C. Kassiotis, A. Papamichalopoulos, J. Milic-Emili, and C. Roussos Resting Lung Function and Hemodynamic Parameters as Predictors of Exercise Capacity in Patients With Chronic Heart Failure Chest, May 1, 2003; 123(5): 1386 - 1393. [Abstract] [Full Text] [PDF]

				S. Nanas, J. Nanas, C. Kassiotis, C. Nikolaou, E. Tsagalou, D. Sakellariou, I. Terovitis, O. Papazachou, S. Drakos, A. Papamichalopoulos, et al. Early recovery of oxygen kinetics after submaximal exercise test predicts functional capacity in patients with chronic heart failure Eur J Heart Fail, December 1, 2001; 3(6): 685 - 692. [Abstract] [Full Text] [PDF]

				Task Force for the Diagnosis and Treatment of Chro, W. J. Remme, and K. Swedberg Guidelines for the diagnosis and treatment of chronic heart failure Eur. Heart J., September 1, 2001; 22(17): 1527 - 1560. [PDF]

				F. J. Meyer, M. M. Borst, C. Zugck, A. Kirschke, D. Schellberg, W. Kubler, and M. Haass Respiratory Muscle Dysfunction in Congestive Heart Failure : Clinical Correlation and Prognostic Significance Circulation, May 1, 2001; 103(17): 2153 - 2158. [Abstract] [Full Text] [PDF]

				E. Pouliou, S. Nanas, A. Papamichalopoulos, T. Kyprianou, G. Perpati, I. Mavrou, and C. Roussos Prolonged Oxygen Kinetics During Early Recovery From Maximal Exercise in Adult Patients With Cystic Fibrosis Chest, April 1, 2001; 119(4): 1073 - 1078. [Abstract] [Full Text] [PDF]