You can’t repair a leaky heart valve when the blood is constantly pulsing through the chambers. So the heart has to be immobilized. Put in a state of suspended animation. Stopped.
It happens soon after the patient has been safely connected to the heart-lung machine, which will take over the work of these two vital organs by pushing blood through the patient’s circulatory system, oxygenating it upon each return to the body, so the surgeon can work on the no-longer-beating heart.
The perfusionist has the dubious honor of stopping the heart by injecting a potassium solution into the web of tubing that returns blood to the body. The process is eerily similar to that of execution by lethal injection. The anesthesiologist already has put the patient into a deep sleep and administered a paralyzing agent. The perfusionist strikes the final blow by effectively killing the heart as the potassium solution interrupts the electrical signaling essential to its functioning.
“The patient literally is dead [at this point],” anesthesiologist George Gellert, M.D., told me. “That’s the kind of pressure these guys are under.”
It happens very quickly. I watched the patient’s heart beating one moment and deflating like a popped balloon the next. Icy slush was packed around the heart; the colder it stayed for the next few hours, the less oxygen it would require to remain viable. The rest of the body would be kept warm and constantly replenished with freshly oxygenated blood, courtesy of the heart-lung machine.
“Nighty, night, Mr. Heart,” someone said.
Tomorrow: A quiet return to life.