Being too clever can complicate diagnosis. Most often it is a problem for the able young doctor, not yet case-hardened, not yet clear that common things are common, and that an unusual presentation of a common disease is more likely than a rarity.
But over-clever errors can afflict us all, no matter how learned and experienced we may be.
This happened to me after nearly a half-century in practice.
Elwyn was 54 years old. He had a hill farm with a flock of sheep. He was tall, slim and fit, and a non-smoker.
So it was a surprise when he was sent to the hospital as a suspected myocardial infarction.
Soon after getting up that morning he had a sudden severe chest pain, which stopped him. He sat down, in pain, and feeling nausea. He felt his heart thumping and became short of breath. The pain subsided after several minutes but the palpitations and breathing difficulty continued.
He had no significant past medical history; and no heart disease in the family.
He had an electrocardiogram on arrival, which showed some anomalies, but not the changes of acute myocardial infarction.
On examination he looked grey, sweaty and ill. He was sitting up, visibly short of breath, and became distressed at any attempted to lie flat. From the foot of the bed I could see pulsation in his carotid arteries.
His pulses were increased and collapsing, at a rate of 100/minute, regular. Blood pressure was over 250 systolic, with no clear diastolic cut-off down to zero.
The immediate suspicion was that he had suffered some sort of acute failure of the aortic valve, so I was surprised to find a forceful apex beat in the right place - in the 5th. left interspace, in the mid-clavicular line. Leaking valves put a volume load on the heart, causing dilation.
The stethoscope revealed a loud diastolic murmur of aortic regurgitation, as expected.
But listening at the apex of the heart I heard a second, low-pitched, diastolic murmur. Austin Flint's name is associated with an apical mid-diastolic murmur, and this was my first thought. But listening further I hear an early diastolic snap, followed by a decrescendo murmur, increasing again before a loud first sound. These are the classical signs of mitral stenosis.
I demonstrated these signs to the house physician and two students, who agreed with me. Well, I suppose they would.
But it didn't make sense. A double valve lesion must mean a heart damaged by rheumatic fever, probably in child-hood, and long-standing valvular disease. But this man had no such history, and was in good health until a few hours before.
An associated mitral stenosis might explain the undisplaced apex beat.
I was perplexed. I called my cardiological colleague. By good fortune he was in the cardiac laboratory; bring down the patient for an echo-cardiogram.
I watched fascinated. The root of the aorta was dilated, and the valve stretched, the cusps not meeting. There was massive reflux of blood into the left ventricle during diastole. The left ventricular cavity was dilated.
The mitral valve was normal, but it could scarcely open in diastole before the flood of reflux had filled the cavity, pushing the mitral valve cusps back and together. The phonogram showed this was the cause of the opening snap I had heard. The diastolic murmur was functional: high left atrial pressure and atrial systole forcing blood through a closed valve into the full ventricle.
And the heart had not dilated because it was all so acute. Over the next few hours it would, with rapidly increasing left ventricular failure.
Elwyn needed emergency surgery. He was transferred to the cardiac surgeons in another hospital that afternoon, who operated that evening. They put in aortic arch and aortic valve prostheses.
The pathologist reported the resected aorta showed cystic medial necrosis, a recognised degenerative condition.
Elwyn did well, but I didn't see him again - he was followed up by the cardiologist. I heard later he decided the farm was too much for him.
As a young doctor studying for a higher examination I had spent many hours practising with the stethoscope. I had become - yes, I'll admit it - proud of my skill with that challenging instrument. On this occasion I had fallen.
Had I not been so clever when I listened I would have got the right diagnosis.