Catheters are small tubes introduced into the heart through blood vessels for obtaining information on the heart and its blood vessels as well as to do procedures to treat heart diseases. Ablation is the process of damaging a disease causing region to prevent its abnormal function. An example is ablation of a tiny region of heart muscle which generates abnormal signals causing very fast heart beats. This process is known as catheter ablation. Most commonly the energy used for the procedure is a controlled delivery of radiofrequency current (RF) to produce localised thermal damage of the abnormal group of cells within the heart. Other forms of catheter ablation may use cooling to very low temperatures (cryoablation) or delivering microwave energy (microwave ablation).