To some, the heart is a red, twitchy lump of meat. To others, it’s an intricate orchestra of specialized cells and fibers. We’re lucky to live in a time when so much research and technology has been put into keeping this organ beating, extending and improving the quality of life. One of the most commonly seen machines is the defibrillator. It’s simple and only does one thing: it stops all electrical activity in the heart momentarily.
The heart is made out of cardiac muscle cells that contract. Intertwined in them are other types of cells called pacemaker cells. As their name suggests, pacemaker cells are in charge of making sure the cardiac muscle cells contract in sync. Without these pacemaker cells, the heart becomes a quivering mass of flesh that cannot pump blood*.
There’s actually a science word for a heart that’s out of rhythm: fibrillation. A defibrillator, as mentioned above, sends an electrical shock to the heart and basically stops all the cells from moving. This allows the pacemaker cells to reset the rhythm again. It’s basically like troubleshooting any electronic device: turn it off, turn it back on.
Sometimes, the most dangerous and confounding problems have the simplest solution. For all the complexities of being alive and being human, what keeps our hearts beating for 70, 80-something years is this collection of pacemaker cells. We thought they were important enough to warrant their own piece of jewelry: the electrical circuit of the heart necklace. Without this tiny group of well-placed cells, your heart would, in fact, just be a red, twitchy lump of meat.
*In humans and other similar mammals. There are many organisms that don’t have pacemaker cells, such as fruit flies and other invertebrates. Scientists aren’t quite sure what synchronizes their heartbeats.
