Pulmonary artery dissection is a rare and lethal condition. Few cases are reported in the literature, and most are derived from autopsies. In most cases, pulmonary artery dissection is a complication of chronic pulmonary hypertension leading to pulmonary artery aneurysm but there are other causes. We describe a case of iatrogenic pulmonary artery dissection in an elderly patient with ostium secundum defect. In particular, we describe the role of cardiac magnetic resonance in making this diagnosis and guiding future therapeutic decisions.