Z422 – Retrograde aortic left heart catheterization
OHIP Psychiatric Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Retrograde aortic left heart catheterization with or without pressure measurement(s). This procedure is only eligible for payment when rendered with electrophysiologic pacing and mapping (G176), catheter mapping (G177), and/or catheter ablation therapy (G178). The service is limited to a maximum of one per electrophysiological pacing, mapping, and/or ablation sitting. This service is eligible for surgical assistant and anaesthesia services, which are calculated based on basic and time units.
When to Use
- Use Z422 when performing retrograde left heart catheterization specifically to facilitate access for electrophysiological mapping (G177) or ablation therapy (G178).
- Use this code when pressure measurements are taken via the retrograde aortic route during an electrophysiological study (G176) to assess hemodynamic status.
Common Pitfalls
- Billing Z422 as a standalone diagnostic procedure; it will be rejected unless submitted on the same claim as G176, G177, or G178.
- Attempting to bill Z422 multiple times for a single electrophysiological session; the code is strictly limited to one per sitting regardless of the number of catheters or mapping points used.
Billing Tips
- Ensure the primary procedure (G176, G177, or G178) is clearly documented to support the necessity of the retrograde aortic access provided by Z422.
- When claiming for a surgical assistant, use M400B and ensure the surgeon provides a specific letter of justification, as the assistant fee is not automatically linked to the Z422 base code.
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Surgical
Diagnostic and Therapeutic Procedures, Cardiovascular Surgical Procedures
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