Upon arrival, the cardiologist is still concerned about the diagnosis. He decides to review the inflight recordings and TTE together with the other available clues. He returns to the patient, listens for the diastolic murmur reported at initial examination, notes that the pain was non-stress induced and considers the dilated aortic root. He tries to think of an alternative diagnosis which could integrate all of these clues, thinking through different possible aortic conditions, and realizes that a dissecting thoracic aortic aneurysm11could explain all of these symptoms: the dilated root is part of the aneurysm and a small flap in the beginning tear could produce the murmur. The patient is taken directly to surgery where ascending (type A) aortic dissection is repaired. He was discharged home after one week.
Commentary: Given the state of the patient, the physicians are forced to act even though the evidence remains puzzling. The cardiologist does not consider the diagnosis of cardiac ischemia particularly likely due to the lack of expected observations (minimal pain relief from morphine, non-diagnostic cardiac enzymes and ECG). But he currently lacks a plausible alternative.
He chooses a strategy for generating an alternative diagnosis, deciding to review all of the available clues, including ones that initially were not considered salient (the soft murmur), to guide his search for alternative diagnoses. Like the emergency room clinician, given the negative result for embolism, he considers the most serious remaining possibility an acute aortic syndrome, also suggested by the dilated aortic root. Relying on his background knowledge, he directs his attention towards possible aortic syndromes and quickly thinks of a possibility—a dissecting aneurysm—capable of explaining the symptoms. Once he has in mind this newly generated hypothesis he immediately recognises that it would be able to explain all of the otherwise puzzling evidence. On this basis, he judges it more likely than ACS and decides to adopt it as a basis for the surgical intervention. While one cannot guarantee such judgements to always be correct, given the urgency of the situation, it was in this case a reasonable and, fortunately, successful approach.