Micra Leadless Pacemaker Implantation – Practical Stepwise
Overview
This document summarizes the practical procedural workflow, handle controls, locking mechanism, and
troubleshooting points during implantation of the Medtronic Micra leadless pacemaker system.
1. Femoral Venous Access
Right femoral venous access is commonly preferred. Initial puncture is often obtained using micropuncture technique
followed by serial dilation. Final introducer sheath size is approximately 27F outer diameter and 23F inner diameter.
Because the sheath is large, ultrasound-guided access and careful venous puncture are important to avoid vascular
complications.
2. Advancement of Sheath and Delivery System
A stiff guidewire such as an Amplatz Super Stiff wire is advanced into the SVC. The large introducer sheath is then
positioned into the right atrium. The Micra delivery catheter is advanced through the sheath into the RA, across the
tricuspid valve, and into the right ventricle.
3. Target Implant Position
Preferred implantation site is usually the RV septum or apical septal region. Free wall deployment should be avoided
because of perforation risk. Fluoroscopic RAO and LAO views help confirm septal positioning.
4. Main Controls on the Micra Delivery Handle
The delivery handle contains multiple control systems:
A. Deflection Control: Used to flex and steer the catheter toward the RV septum.
B. Deployment Mechanism: Used to deploy the nitinol fixation tines into myocardium.
C. Locking Button / Lock Switch: A safety mechanism that prevents accidental deployment or unintended release
of the device. It stabilizes the tether and deployment system during positioning and recapture. The lock essentially
keeps the system in a “safe” state until intentional deployment and release are desired.
5. Importance of the Locking Mechanism
The locking system prevents premature release of the device while the operator is still evaluating fixation and
electrical parameters. Before final release, the Micra remains attached to a tether and can still be recaptured and
repositioned.
