Prognostic value and diagnostic potential of cardiopulmonary exercise testing in patients with chronic heart failure.

Cardiopulmonary exercise testing (CPET) is a well established technique for stratifying cardiovascular risk in patients with chronic heart failure (CHF). Important prognostic variables include a reduced peak oxygen uptake which has a central use in cardiac transplant selection, and the abnormal relation between minute ventilation (VE) and carbon dioxide production (VCO(2)), often referred to as the elevated VE/VCO(2) slope. We will discuss the pathophysiology of these abnormal responses to exercise in CHF, and how these are interpreted during CPET. The potential of CPET for diagnosing circulatory, respiratory, metabolic, musculoskeletal or mixed limitations is an emerging field of research. We will speculate on how CHF manifests during CPET, and clarify the pathophysiological basis of these exercise responses. To improve our understanding of the diagnostic value of CPET, further investigation is required by clinicians to develop reference ranges for CHF patients from a co-ordinated multicentre approach. The use of CPET technology is becoming increasingly prevalent in cardiology services, and it is likely that, in the future, CPET will take a more prominent role in guiding patient management provision.