Your heart beats because of a group of cells called pacemakers that generate electrical impulses. These pulses then spread over the entire heart, causing it to contract. This happens more than once per second, producing a normal heartbeat of 72 beats per minute. But some people's hearts develop faulty cells that produce electric impulses out of sync with the rest of the heart. This condition is known as arrhythmia.
Cryoablation is a form of surgery that freezes heart muscle to stop it from carrying those irregular electrical signals. It does not inject cold into tissue; rather, it removes heat from the target area to slow cellular activity.
To locate the target area, doctors cool (but not freeze) the heart muscle to suspend electrical activity without damaging the tissue. This enables them to find out whether a particular area is causing the arrhythmia. Once doctors find out where the problem is, the catheter is placed at the target area and the temperature of its tip is lowered to -70 degrees Celsius. This freezes the tissue and kills the cells causing the arrhythmia.
A similar treatment for arrhythmia is called radiofrequency (rf) ablation. Tiny bursts of intense radio waves go through a catheter and burning or charring the tissue near the catheter without harming other nearby tissue. This heating, like the freezing, counteracts the irregular electrical impulses in heart muscle.
The first cryoprobe was invented in 1961. But it wasn't until the late 1980s that ultrasound imaging techniques were sophisticated enough to help surgeons map and monitor the process. Cryosurgery was initially used to freeze liver tumors, and is a common treatment for prostate tumors.