Leadless cardiac pacemakers are a recently introduced type of cardiac conduction device. These pacemakers are self-contained right ventricular single-chamber pacemakers that are implanted percutaneously via a femoral approach . There are currently two leadless cardiac pacemakers on the market: Nanostim™️ (Abbott Medical) and Micra™️ (Medtronic).
A leadless cardiac pacemaker can be appreciated on plain chest radiographs or CT scans as a radiolucent oblong-shaped small device in the right ventricle . It is important to not mistake this device, especially on a PA view plain radiograph, for the similarly-shaped implantable loop recorder .
Depending on the brand, the exact size varies :
- Nanostim Leadless Cardiac Pacemaker (Nanostim LCP): 4.2 cm x 0.6 cm
- Micra™️ Transcatheter Pacing System (Micra™️ TPS): 2.6 cm x 0.7 cm
Both devices are compatible with 1.5 T and 3 T body MRI .