The role of invasive cardiopulmonary exercise testing in patients with unexplained dyspnea: a systemic review.

Invasive cardiopulmonary exercise test is a useful tool for identifying the cause of unexplained dyspnoea. It can be helpful in early recognition and prognostication of patients with heart failure with preserved ejection fraction and pulmonary hypertension. It has also shown to be beneficial for constructing a multidisciplinary approach to chronic dyspnoea.