As all students know, being a good test-taker obscures many knowledge gaps, something that is both blessed and cursed. Blessed because we can eliminate answers based on wording or information supplied by previous questions, and cursed because “Which one is incorrect?” can be followed by “Which one is correct?”, which can then be followed by “Which one is NOT correct?” Heaven help you if there are also some “All of the following are incorrect EXCEPT…” questions thrown in there.
But I digress. My point is, students who take numerous exams become used to honing in on the details. A single word is often the only difference between a statement being true or false. And when we take tests this way, that means we often learn this way as well. We dissect new information in anatomical detail, so we don’t miss those tiny details so often tested by professors. C-terminal brain natriuretic peptide is the active form of BNP, which mediates beneficial vasodilation and salt excretion during heart failure. But N-terminal pro-BNP, while inactive, has a longer half-life and so circulates in the blood longer…so when we test a dog’s blood for BNP, we’re really testing for NT-proBNP. Answering a multiple choice question correctly tests whether we have memorized the details, but it doesn’t prove whether we understand that high levels of BNP help reduce how hard the heart must work to pump out blood.
Studying for our first cardiology exam was a humbling experience, because while trying to distinguish right bundle branch block from premature ventricular contractions on an ECG I realized with a sinking feeling that I didn’t have a clue about what these electrical patterns really meant. Do premature ventricular contractions reduce the amount of blood the heart can pump out? Do they cause the heart to add more muscle and get bigger? Do premature ventricular contractions indicate severe heart disease, or are they pretty benign, an incidental finding? These are things I definitely should know for the sake of my patients, and the answers to them can be found buried in our lectures. Just as a good forester knows each of his trees like an old friend, he also knows his way through the forest—he knows where to jump over streams or avoid a swamp, and he knows where the forest is thickest and where it peters out.