Arrhythmias in Pulmonary Hypertension Assessed by Continuous Long-term Cardiac Monitoring

In general there is a lack of evidence of the arrhythmic burden in PH. The present study is the first to apply continuous long-term cardiac monitoring in patients with PH to describe the prevalence of arrhythmias in PH by continuous long-term cardiac monitoring. Furthermore, the correlation between heart rate variability and risk assessment parameters including WHO functional class (FC), NT-proBNP, 6MWT, cardiac parameters and cardiac function will be studies. A few prospective studies have demonstrated lower HRV in PH than in healthy individuals, however only based on short-term monitoring (20 minutes to 24 hour) and only in a few patients. In retrospective studies, a higher mortality in children with PAH and low HRV has been shown with 24 hour Holter monitoring. Consequently, there is a lack of evidence regarding right heart failure and the prognostic value of HRV. Risk assessment in PH is essential in the selection of treatment in PH and for prognosis in the study ASPIRE the investigators will assess the use of heart rate variability in pulmonary hypertension. In conclusion the ASPIRE study will: 1. Assess the incidence and prevalence of arrhythmias using long term cardiac monitoring via a reveal LINQ loop recorder (Medtronic). Furthermore, the investigators will assess; Change in cardiac index, right atrial size, RV size, fibrosis and stroke volume. 2. The investigators will assess the arrhythmic burden in relation to: * Change in 6 MWT * Hemodynamic changes with RHC * Hemodynamic changes in echocardiography * The number of patients progressing one FC (Modified NYHA class) * Changes in NT-proBNP. * Hospital admission for any reason * Death or transplantation 3. Monitor heart rate variability and address a comparison to known risk markers and CMR and echocardiography. The study specifically seeks to investigate following: * The incidence and type of supraventricular and ventricular arrhythmias in PH by continuous long-term monitoring * The predictive value of both right and left ventricular cardiac magnetic resonance (CMR) imaging parameters for arrhythmogenesis in PAH, heart rate variability, and heart rate. * Optimization of specific therapy in PAH using continuous long-term arrhythmia monitoring 4. Monitor patients using smart watches (apple watches) to evaluate the applicability of long-term monitoring via apple watches in patients with pulmonary hypertension for irsk asessment.