Question category: Respiratory
A 48 year old female presents with dyspnoea and syncope on exertion. She is a non smoker and has no past medical history. On examination she has a raised JVP, right parasternal heave, loud pulmonary second heart sound and peripheral oedema. Her chest is clear. An ECG reveals right ventricular strain pattern and CXR shows prominent pulmonary arteries. She now admits to having used fenfluramine in the past. What is the most likely diagnosis?