Clinical study of world’s smallest pacemaker begins in US

A clinical trial programme has begun in the US to assess the safety and efficacy of the smallest cardiac pacemaker yet created.

Developed by manufacturer Medtronic, the Micra Transcatheter Pacing System (TPS) is being implanted in patients at various medical centres, including Ohio State University's Wexner Medical Center and the Minneapolis Heart Institute Foundation.

The device is one-tenth the size of a conventional pacemaker, roughly equal to an average vitamin pill. It is delivered directly into the heart through a catheter inserted in the femoral vein, before being secured to the heart wall.

Instead of using conventional leads, the wireless pacemaker delivers electrical impulses through an electrode at the end of the device that help regulate the heart's rhythm.

Dr John Hummel, a cardiologist and principal investigator of the trial at Ohio State University, said: "With this investigational device, the battery, the pacing electrodes, everything is in a little piece of metal sitting inside the heart. We believe that will eliminate a lot of risk for infection and complications."

The trial will enroll 780 patients at 50 centres worldwide, with initial results expected later this year after the first 60 patients have been followed for three months.