Reconstruction	Analysis
Presentation
Patient in 70's came with breathlessness  … the first thing was he kept saying to me ‘this is exactly like it was about 6 months previously’ … looked back in his notes and 6 months previously he'd been diagnosed with heart failure and so I thought ‘well, you know’ and he was so insistent that it was the same thing …. he was a bit breathless but there wasn't anything really obvious going on  … so I thought maybe he was anaemic as well and that had got worse. And it was a Saturday morning so I couldn't easily get any tests straight away so I booked for him to come back first thing on Monday morning for blood tests and ECG and I sent him up to the hospital for a chest x-ray. He was so insistent that it was the same thing and in retrospect that was really misleading for me	Salient feature was patient's insistence that the diagnosis was the same as previously, seemingly confirmed by looking at case notes of his previous presentation System 2 in action as tests ordered, largely to rule in cardiac failure and rule out possible complicating factor of anaemia
Context issues
It was a Saturday morning so I couldn't easily get any tests straight away	Management affected by practice environment—routine blood tests not immediately available
Outcome
Next day contacted by one of his friends  … to say ‘actually, he's had a pulmonary embolism  … he'd got quite a lot worse that afternoon and been admitted to hospital and  …CT showed multiple pulmonary emboli	Delay in diagnosis likely to System 1 overpowering System 2, raising closure threshold enough to be affected by context issues (no blood tests available at weekend)
Summary
System 1 single diagnosis based on the existing label immediately jumps to the diagnosis. Weak System 2 affected by context issues, delaying diagnosis.