Patients with systemic sclerosis (SSc) related pulmonary arterial hypertension (SScPAH) have a worse prognosis than those with idiopathic PAH. We have recently discovered that heart cells in SScPAH do not contract or squeeze as well as in other forms of pulmonary hypertension. However, the mechanism leading to this dysfunction is not understood. To better study this and in hopes of developing a future therapy, we plan to collect tissue samples via a heart biopsy at the time of a clinically indicated heart catheterization.