Question special

This may not be as pertinent to preoperative testing for cataract surgery, but I wonder if we could discuss the best approach to investigating a new heart murmur. And in doing so, flush out how best to deal with uncertainty.

The ACC/AHA guidelines on perioperative care prescribe that -- when a new murmur is detected -- clinicians need to decide whether or not it represents significant valvular disease. But how do we decide? If we delve a little deeper, the Appropriate Use Criteria for TTE suggest that investigating this murmur without other signs or symptoms of valvular disease is rarely warranted. What are these rare circumstances?

More broadly, if guidelines are not designed to give specific advice at the point-of-care, where do we turn?