What do this shack and a little girl have to do with an EKG?

So there's a foundation, Hearts for Kids, that helps kids in Africa get heart transplants. That's awesome. This picture, from their website, is where their patients live.

I don't know anything about them, I just found them with Google while I was searching for rheumatic fever. If you do a Google image search for the same, you'll see a lot of black and white pictures from the pre-antibiotic era of people who died from RF, including Mozart. Then I saw this picture. Not black and white. Full color. Hmmm.

RF is still on our diagnosis list of kids with fever and migratory rash; it can attack the heart most famously, or cause people to have similar symptoms to Huntington's disease, also known as Syddenham's chorea. During a grand rounds last week, a distinguished class of residents at a top program didn't recognize a video of it. That video was taken in Africa. To learn about it, I've had to use the Internet, textbooks, and slides, because I've never seen a case, and likely never will until I travel overseas.

According to an NEJM article, rheumatic fever in the US has decreased precipitously. From being a more common topic than stroke in the era from 1967 to 1976, it is now rare, and a search of all medical journals in the US yields only eight articles between 1997 and 2006. But in places like that in the picture above--that is, the 80% of the world without access to prompt antibiosis for strep throat--there are 470,000 new cases of ARF each year.

What got me on this topic? EKGs, actually. Wolff-Parkinson-White syndrome is a sub-set of supraventricular tachycardias, or fast heart rhythms. It is a characteristic, classic finding on an EKG; there is a bit of an early rise in the QRS complex called the delta wave, and it represents a track of heart muscle that goes around the normal pathway of conduction. It typically does not cause problems (story to the patient) but can proceed to ventricular fibrillation (story to students) if you block the normal pathway.

Our hearts have a built in delay to allow for filling of the ventricles. Because the WPW pathway bypasses that system, if it becomes ascendant, it conducts directly from the atria to the ventricles at a rate of anywhere from 150-300 beats per minute. That is sometimes called 'badness'. If the patient is unstable, the best treatment is to shock them (electrical cardioversion). If they are stable but fast, a variety of drugs can be used; I learned that adenosine, which is usually used even in the field by paramedics for narrow-complex tachycardias should not be used for WPW, but some texts seem to suggest it is acceptable. I'll have to read more to figure out the differences.

WPW was first described by a few physicians, as often happens, but Paul Dudley White, who worked at Harvard at the turn of the century, described it in 1908. It is interesting to note why he became a physician, and to wonder why he decided to focus on the heart. He, like countless others at the turn of the century, before the advent of penicillin, lost a sister to acute rheumatic fever at the age of 12.

No comments: