11th May 2025

A 45-year-old woman presents to general practice with progressive dyspnoea on exertion.

A 45-year-old woman presents to general practice with progressive dyspnoea on exertion. She has no past medical history and takes no regular medications. You perform initial work up with a chest x-ray, ECG and bloods (full blood count, urea and electrolytes and liver function tests), all of which are normal. Transthoracic echocardiogram shows elevated estimated mean pulmonary pressures. 

Which of the following investigations is gold standard in diagnosis of pulmonary hypertension? 

Select the SINGLE most appropriate option from the list below. Select ONE option only.