“I was born with a decent size hole in my heart and my parents were told that it would eventually go away with time. It didn’t, and progressed into irregular beating and cardiac arhythmia. Finally, when I was 18, my doctor noticed that the sound of my heart had changed and that she didn’t think it was functioning the way it should be. I went to a specialist and he determined that the AV node was blocked and that my heart was only beating half of what it should be. I got a pacemaker on December 23, 2003 when I was just 18. A couple years later, as a Christmas gift, my fiance paid for me to get the medical symbol for the pacemaker tattooed on my upper right wrist.”
“I am an evolutionary biology graduate student working with some of the world’s earliest known HIV samples, trying to clarify the early evolutionary history of the virus. I was inspired by an elegant circle tree phylogeny my PI put together for a publication submission and I decided I had finally found something I connected with enough to get permanently put on my body.”
“The first is an ECG, single lead, called a rhythm strip, which shows a common and generally benign arrhythmia called second degree heart block, Mobitz Type I, also called Wenckebach. The interval between the P wave (atrial contraction) and the QRS (ventricular contraction) progressively increases till a QRS is dropped. The second is a three-lead ECG showing an acute inferior myocardial infarction, aka a heart attack.”
Carl writes: When you stop to reflect on electrocardiograms, it is remarkable that we can peer within the heart simply by picking up tiny changes in voltage on the skin. The fact that muscles such as the heart use electricity to drive their contractions was inconceivable in the 1600s. Natural philosophers believed muscles might be inflated by “animal spirits,” but the idea that the same power in a lightning bolt was at work in our hearts every second of our lives would have seemed absurd. Jan Swammerdam, a Dutch anatomist, tried to persuade his contemporaries in the 1660s that animal spirits did not drive the heart–he showed that a severed muscle twitched if he touched its nerve endings with the blade of a scalpel–but it would take well over a century for scientists to accept that our lives depend on a rhythm of sparks.