They are miniaturised devices (pacemakers) that are implanted if the heart rate becomes abnormally slow (bradycardia), which can lead to a feeling of unwellness. The patient is given a local anaesthetic and the surgeon introduces the pacemaker under the skin, below the right collarbone, and into a vein. Using X-ray guidance, it is then positioned in the appropriate chamber of the heart. The intervention generally takes 20 to 60 minutes, thanks to the dexterity of the surgeons who in the canton of Fribourg are pioneers in this field.