Examples of applications include Assessment of exercise capacity for disability evaluation Preoperative assessment Determination of whether dyspnea symptoms result from cardiac or pulmonary problems in patients who have disorders of both organ systems Selection of candidates for heart transplantation Assessment of prognosis in selected disorders (eg, heart disease, pulmonary vascular disorders, cystic fibrosis) CPET can also help gauge responses to therapeutic interventions and guide prescription of exercise in rehabilitation programs.