Monday, September 10, 2007

Minerva's Owl Flies at Dusk

A young woman presents to the clinic. She has involuntary fast jerking movements of her face and all her limbs. They are uncoordinated and include facial grimacing and an unstable gait. She has a history of painful joints. On heart exam, you hear this:

http://casematerials.googlepages.com/COTD1.mp3

Challenge: What's the diagnosis?

Related Questions:
1. What is the heart murmur?
2. What is the movement disorder?
3. What is the pathophysiology of this disease?
4. What famous 19th century philosopher said the phrase in the title of today's case?

The mp3 audio file is linked under Fair Use. It can be freely downloaded from an American College of Cardiology website; this mp3 has been edited with the program Audacity. The specific source will be indicated in the solution to this case.

3 comments:

Alex said...

1) diastolic murmur
2) Sydenham's chorea
3) stems from rheumatic fever.
4) had to google this.. Hegel? what's the story?

Mika said...

1. I turned the volume up as high as I could and I couldn't hear a thing. I could barely hear the normal heartbeats. So much for my future in cardiology. At any rate, I think the specific form of rheumatic carditis you are looking for is either aortic insufficiency or mitral stenosis. Since the guy said to put the stethoscope at the apex, my guess is AI.
2. Choreoathetosis
3. Untreated group A strep throat infxn > cross-reaction with myocardium > chronic repeated inflammation
4. Hegel

Craig said...

Minerva’s Owl Flies at Dusk

(Sorry about the low volume, I tried amplifying it but it doesn't help much)

The heart murmur is a low-pitch diastolic murmur with an opening snap best heard at the cardiac apex; this would be mitral stenosis. Most cases of mitral stenosis are due to rheumatic heart disease. This is supported by the movement disorder which is Sydenham’s chorea, also associated with rheumatic fever. Lastly, arthralgia is classified as a minor criteria for rheumatic fever. Rheumatic fever is caused by antibody cross-reactivity, perhaps due to molecular mimicry. After an untreated Group A streptococcal pharyngeal infection, autoantibodies against the myocardium and joints can be formed. This is a Type II antibody-antigen hypersensitivity reaction. Chronic rheumatic heart disease occurs due to repeated bouts of inflammation causing leaflet thickening and mitral stenosis. The phrase “Minerva’s Owl Flies at Dusk” is attributed to Hegel.

Sources: Wikipedia. The audio file is taken from “Heart Songs,” Cardiosource, American College of Cardiology (http://www.cardiosource.com/heartsounds/index.asp). The file is created by Michael Barrett, MD and freely downloadable from the website. The website also has many other audio files and a CD of heart sounds can be purchased. This website was accessed 9/7/07.