Heart 1998;79:289-294 ( March )

Physiological cardiac reserve: development of a non-invasive method and first estimates in man

G A Cooke, P Marshall, J K Al-Timman, D J Wright, R Riley, R Hainsworth, L B Tan

Institute for Cardiovascular Research, University of Leeds and Yorkshire Heart Centre, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK

Correspondence to: Dr Tan.

Accepted for publication 3 November 1997

ObjectiveTo investigate whether physiological cardiac reserve can be measured in man without invasive procedures and whether it is a major determinant of exercise capacity.
DesignDevelopment of method of measurement and an observational study.
SettingA regional cardiothoracic centre.
Subjects70 subjects with a wide range of cardiac function, from heart failure patients to athletes.
MethodsSubjects underwent treadmill, symptom limited cardiopulmonary exercise tests to measure aerobic exercise capacity (represented by O₂max) and cardiac reserve. Cardiac output was measured non-invasively using the CO₂ rebreathing technique.
ResultsCardiac power output (CPO_max) at peak exercise was found to be significantly related to aerobic capacity: CPO_max (W) = 0.35 + 1.5O₂max (l/min), r = 0.87, p < 0.001. It also correlated well with exercise duration (r = 0.62, p < 0.001), suggesting that cardiac reserve is a major determinant of exercise capacity. In the study, cardiac reserve ranged from 0.27 to 5.65 W, indicating a 20-fold difference between the most impaired cardiac function and that of the fittest subject.
ConclusionsA non-invasive method of estimating physiological cardiac reserve was developed. The reserve was found to be a major determinant of exercise capacity in a population of normal subjects and patients with heart disease. This method may thus be used to provide a clearer definition of the extent of cardiac impairment in patients with heart failure.

Keywords: cardiac reserve;  cardiac power output;  oxygen consumption;  congestive heart failure

---

© 1998 by Heart
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Patwala, A., Woods, P., Clements, R., Albouaini, K., Rao, A., Goldspink, D., Tan, L.-B., Oo, A., Wright, D. (2009). A prospective longitudinal evaluation of the benefits of epicardial lead placement for cardiac resynchronization therapy. Europace 11: 1323-1329 [Abstract] [Full Text]  
• Patwala, A. Y., Woods, P. R., Sharp, L., Goldspink, D. F., Tan, L. B., Wright, D. J. (2009). Maximizing Patient Benefit From Cardiac Resynchronization Therapy With the Addition of Structured Exercise Training: A Randomized Controlled Study. J Am Coll Cardiol 53: 2332-2339 [Abstract] [Full Text]  
• Otasevic, P, Popovic, Z B, Vasiljevic, J D, Pratali, L, Vlahovic-Stipac, A, Boskovic, S D, Tasic, N, Neskovic, A N (2006). Head-to-head comparison of indices of left ventricular contractile reserve assessed by high-dose dobutamine stress echocardiography in idiopathic dilated cardiomyopathy: five-year follow up. Heart 92: 1253-1258 [Abstract] [Full Text]  
• Schlosshan, D., Barker, D., Pepper, C., Williams, G., Morley, C., Tan, L.-B. (2006). CRT improves the exercise capacity and functional reserve of the failing heart through enhancing the cardiac flow- and pressure-generating capacity. Eur J Heart Fail 8: 515-521 [Abstract] [Full Text]  
• Chantler, P D, Goldspink, D F, Clements, R E, Sharp, L, Schlosshan, D, Tan, L-B (2006). Congestive heart failure: extent of cardiac functional changes caused by aging and organ dysfunction.. Heart 92: 686-688 [Full Text]  
• Chantler, P. D., Clements, R. E., Sharp, L., George, K. P., Tan, L.-B., Goldspink, D. F. (2005). The influence of body size on measurements of overall cardiac function. Am. J. Physiol. Heart Circ. Physiol. 289: H2059-H2065 [Abstract] [Full Text]  
• Otasevic, P., Popovic, Z. B., Vasiljevic, J. D., Vidakovic, R., Pratali, L., Vlahovic, A., Nesskovic, A. N. (2005). Relation of myocardial histomorphometric features and left ventricular contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy. Eur J Heart Fail 7: 49-56 [Abstract] [Full Text]  
• Williams, S. G., Ng, L. L., O'Brien, R. J., Taylor, S., Wright, D. J., Tan, L.-B. (2004). Is plasma N-BNP a good indicator of the functional reserve of failing hearts? The FRESH-BNP study. Eur J Heart Fail 6: 891-900 [Abstract] [Full Text]  
• Burniston, J. G., Ng, Y., Clark, W. A., Colyer, J., Tan, L.-B., Goldspink, D. F. (2002). Myotoxic effects of clenbuterol in the rat heart and soleus muscle. J. Appl. Physiol. 93: 1824-1832 [Abstract] [Full Text]  
• Cooke, G.A., Williams, S.G., Marshall, P., Al-Timman, J.K., Shelbourne, J., Wright, D.J., Tan, L.-B. (2002). A mechanistic investigation of ACE inhibitor dose effects on aerobic exercise capacity in heart failure patients. Eur Heart J 23: 1360-1368 [Abstract] [Full Text]  
• Nicholls, D.P., O'Dochartaigh, C., Riley, M.S. (2002). Circulatory power--a new perspective on an old friend. Eur Heart J 23: 1242-1245  
• Williams, S.G, Cooke, G.A, Wright, D.J, Parsons, W.J, Riley, R.L, Marshall, P, Tan, L-B (2001). Peak exercise cardiac power output; a direct indicator of cardiac function strongly predictive of prognosis in chronic heart failure. Eur Heart J 22: 1496-1503 [Abstract]  
• Nair, R. U., Williams, S. G., Nwafor, K. U., Hall, A. S., Tan, L.-B. (2001). Left ventricular volume reduction without ventriculectomy. Ann. Thorac. Surg. 71: 2046-2049 [Abstract] [Full Text]  
• Sun, X.-G., Hansen, J. E., Stringer, W. W., Ting, H., Wasserman, K. (2001). Carbon dioxide pressure-concentration relationship in arterial and mixed venous blood during exercise. J. Appl. Physiol. 90: 1798-1810 [Abstract] [Full Text]  
• Armstrong, G P, Carlier, S G, Fukamachi, K, Thomas, J D, Marwick, T H (1999). Estimation of cardiac reserve by peak power: validation and initial application of a simplified index. Heart 82: 357-364 [Abstract] [Full Text]  
• Wright, D J, Tan, L B (1999). Classic techniques in medicine: The role of exercise testing in the evaluation and management of heart failure. Postgrad. Med. J. 75: 453-458 [Abstract] [Full Text]