This is a special type of pacemaker which is used for some patients whose heart is weakened (‘Heart Failure’) and is also inefficient. Unfortunately, it is not a useful treatment for all patients with heart failure (only those with certain features). Three wires (‘leads’) are passed through the vein behind the left collarbone and down into the heart. One lead is positioned in the top chamber (right atrium), and one into each of the bottom chambers (ventricles) of the heart. The leads in the ventricle can then be used to improve the coordination and efficiency of the heart to make the patient feel stronger. There is a small risk of complications, such as bleeding, infection, puncturing the lung behind the vein (behind the collarbone), and one of the leads displacing. The risk of any of these is usually no more than 1 in 100. The patient will need to have the pacemaker checked regularly. This is done simply by putting a header (which looks a little like a computer ‘mouse’) over the skin above the pacemaker. The header is connected to a programmer which retrieves information about how the heart has been behaving since the last check. Changes can also be made to the settings of the pacemaker in this way. Patients are usually seen one month after the procedure, and then every three months after that.