CPT® Code 0515T

1. Indications

The insertion of a wireless cardiac stimulator for left ventricular pacing is indicated for patients who require enhanced cardiac resynchronization therapy (CRT) but face challenges with conventional pacing methods. The following conditions may warrant this procedure:

• Inadequate CRT: Patients who do not achieve effective cardiac resynchronization with traditional external left ventricular pacing methods.
• Anatomical Challenges: Individuals with anatomical issues that complicate the placement of conventional LV pacing wires.
• Lead Dislodgment: Patients who experience dislodgment of the pacing lead, leading to ineffective therapy.
• Unintended Nerve Stimulation: Cases where conventional pacing may inadvertently stimulate nearby nerves, causing complications.
• Poor Ventricular Response: Patients who demonstrate a poor response to conventional pacing techniques that stimulate the LV externally.

2. Procedure

The procedure for the insertion of a wireless cardiac stimulator involves several detailed steps to ensure proper placement and functionality of the device:

• Step 1: The procedure begins with the creation of a subcutaneous pocket in the left anterior chest. An incision is made in the mid-axillary line, lateral to the parasternal border, typically within the 4th to 6th intercostal spaces. This pocket is designed to house the generator.
• Step 2: Transthoracic echocardiography may be performed to identify an optimal acoustic window, which is a region free of bone and lung that could obstruct communication between the external transmitter and the implanted electrode.
• Step 3: The transmitter is inserted into the previously created pocket and secured in place with sutures to ensure stability.
• Step 4: A second incision is made adjacent to the transmitter pocket to create another subcutaneous pocket for the battery. A tunnel is fashioned between the two pockets to accommodate the connecting cable.
• Step 5: The battery is inserted into its pocket, connected to the transmitter via the cable, and secured with sutures to prevent movement.
• Step 6: Percutaneous vascular access is established in a groin vessel to facilitate the retrograde delivery of the pacing electrode. Using standard catheterization techniques, the pacing electrode is advanced through the sheath to a position within 5-10 mm of the tip.
• Step 7: Multiple locations within the ventricle are tested to identify the optimal site for pacing, ensuring the best electrical pattern is achieved.
• Step 8: The tiny receiver electrode is deployed and anchored into the ventricular endocardium, allowing it to effectively receive pacing signals.
• Step 9: The wireless stimulator detects the pacing pulse from the co-implanted conventional pacemaker and transmits ultrasound energy to the receiver electrode, which converts it into electrical energy to synchronize ventricular pacing.
• Step 10: Finally, the devices are interrogated and programmed to ensure optimal function and performance.

3. Post-Procedure

After the procedure, patients may require monitoring to assess the functionality of the implanted system. Expected recovery includes observation for any complications related to the surgical incisions and the proper functioning of the pacing device. Patients may be advised on activity restrictions and follow-up appointments for device interrogation and programming adjustments. It is essential to ensure that the pacing system is operating effectively to provide the necessary cardiac resynchronization therapy.