World’s smallest and lightest leadless pacemaker MICRA implanted at Fortis Malar Hospital


Consultant heart Failure & Interventional Cardiologist,
Fortis Malar Hospital, Adyar, Chennai
Young National Ambassador of European Association of Percutaneous Cardiovascular Interventions (EAPCI) for India

31 years lady diagnosed to have very complex cyanotic congenital heart disease (complete atrioventricular canal defect with Eisenmenger syndrome), not suitable for corrective surgery, developed atrial tachyarrhythmia and complete heart block with low ventricular rate.
Hence she was advised single chamber permanent pacemaker implantation and eventually MICRA leadless pacemaker was decided.
MICRA pacemaker is the world’s smallest and lightest leadless pacemaker currently available. It is delivered percutaneously via transfemoral venous approach through a catheter and implanted in the right ventricle. It does not require the use of leads. MICRA is 93% smaller (25.9×6.7mm) and also lighter (1.75g) than conventional pacemaker, with an average battery longevity of 12-years and MRI compatibility. It is just the size of a large tablet/capsule. It has >99% higher implant success rate and 63% fewer long-term complications (primarily) than conventional pacemaker.
The uniqueness of this case is MICRA catheter has been manipulated via transfemoral approach in this challenging altered anatomy (tortuous course: intrahepatic interruption of IVC with Azygous continuation draining into SVC and also the presence of septal defects like large ASD, VSD) and MICRA pacemaker deployed successfully in RV septum.
Conventional pacemaker requires a mini surgical procedure associated with issues of lead and chest wall pocket related complications, infection, wound healing and removal of stitches after 1 week etc. On the other hand, MICRA pacemaker procedure is a minimally invasive percutaneous procedure just like undergoing angiography; cosmetically good because no scar in the chest wall; patient can be mobilised on the same day and may be performed as day-care procedure in straightforward cases.