WHAT CAN WE LEARN FROM EXERCISE TESTING BEYOND THE DETECTION OF MYOCARDIAL-ISCHEMIA

Noninvasive cardiopulmonary exercise (CPX) testing has proven useful i n the assessment of heart and lung disease, including cardiac and vent ilatory reserves. CPX includes the monitoring of respiratory gas excha nge, O-2 uptake and CO2 production, together with minute ventilation a nd its components-tidal volume and respiratory rate-together with surv eillance of electrocardiography and blood pressure during supervised, incremental exercise. Exercise responses in anaerobic threshold and/or maximal O-2 uptake are used to grade functional capacity objectively and to predict cardiac reserve (exercise cardiac output), which grades the severity of chronic cardiac or circulatory failure. CPX also serv es to distinguish primary cardiac from ventilatory-based exertional dy spnea.