This is only my Heart Beat

I was listening to my heart tonight. The first year medical students and podiatrists had the essentials of clinical reasoning lab this week, and we all had to mock running through a complete cardiac exam with a partner. What I learned in lab strengthened the self-taught lesson I've been constructing this week: everyone's different. This is obvious in anatomy lab during our dissection of a once living person when we become so careful with our scalpels we are frozen in stasis, not just because we are trying to be respectful of the human body lying before us--though we initiate each lab with protocols permeated with gratefulness--but because the bodies given to science look nothing on the inside like the computer model--also of a once living person. I also discovered during our clinical reasoning lab that my femoral artery is really close to my leg, as opposed to being more ventrally lateral... or laterally ventral.

So I was listening to my different heart tonight. In lecture we were told that there are usually just two heart sounds, S1 and S2. But sometimes, there are other noises that can be categorized as S3 and S4. I was shocked--as I held the bell of my stethoscope over my aorta--that I could definitively hear the S2 split.

S1 is the first heart sound, created by the closing of the mitral and tricuspid valves, the borders between the left and right atria and ventricles, respectively. This is the low beat that haunts miscreants and murderers. S2 is the softer of the heart sounds, created when the aortic and pulmonic valves close, successfully closing off re-entrance to the heart by expelled blood. S2 heart sounds are often split. But in my heart, it almost sounded as if there were three heart beats. Am I so musical that even my organs fill with syncopation? Or maybe I'm still very young. Splitting disappears in advanced age, apparently. Just like I had a heart murmur when I was little--noticeable in the slight whoosh sounded by blood passing through my intraventricular septum--that ultimately disappeared.

When I moved my stethoscope to the mitral auscultatory area, which in most people centers over their left ventricular wall, the S2 split disappeared. Physics. The distance from the base of the heart to the pulmonary artery and aorta split is not huge, but it makes a difference, especially when you consider the medium that sound is traveling through isn't air--it's mostly water. The closing valves, a quarter of a second off each other before, are now almost synchronized. My heart, antagonized for years by swimming, asthma, anemia, and a minor septal defect, is now a little large. Not too large. But it's hypertrophic. Its beating is resplendent.

How weird it was for me to hear my heart, to feel it push against my stethoscope--forcing my hand up into the wiring of my bra--as strong as a magnet or gravity or some other force which is strong but invisible. For the last week, we've been talking about the heart--how it forms in embryos and further develops in fetuses, how it can be used to explain many confusing differential diagnoses. I've seen the inside of a baby's heart beating rapidly, around one-hundred-and-twenty beats per minute, as a laser pointer indicated where the ventricular septum didn't grow fully through the heart's chamber, sectioning off right from left. I wonder if the images we saw were from babies who made it. I'm committed to being pro-choice and plan to stay that way for the rest of my life--it seems like the only rationale position to take as a physician who respects her patients. But, in silence, I wished that the babies that graciously allowed us to learn from their ultrasound videos made it fully into life. After all, I have seen into their hearts. Defective or not, a beating heart is rather miraculous. Especially if you believe that evolution, and only evolution alone, got us to this point where there are a mere 20 heart defects in 1000 births.