Diastolic Exercise Stress Testing in Heart Failure

Patients reporting to the investigators' clinic for in- and outpatient consultation and a HFA-PEFF score of 2-4 points will be recruited if their dyspnea is not sufficiently explained by other causes than HFpEF. Patients will undergo a baseline clinical exam, transthoracic echocardiography with measurement of diastolic parameters, and ECG. NYHA class will be reported, standard lab works (NTproBNP, GFR, CRP, Hb, PLT, blood gas analysis) will be taken. The number of patients with a PAWP increase in right heart catheterization (brachial access under sonographic guidance) from a resting value of \<15mmHg to \>25mmHg during stress testing will be assessed across the four interventions. During bicycle ergometry (semi-supine position) spiroergometric data and gas exchange variables (cardiopulmonary exercise testing) will be co-assessed. Between the testing modalities a 10-minute break will allow hemodynamic variables to normalize.