Is Left Anterior Fascicular Block (LAFB) a contraindication to surgery?

Left Anterior Fascicular Block (LAFB) is Not a Contraindication to Surgery

Left Anterior Fascicular Block (LAFB) alone is not a contraindication to surgery and does not require special management or preoperative intervention.

Understanding LAFB in the Surgical Context

LAFB is a conduction abnormality affecting the left anterior fascicle of the left bundle branch. When evaluating patients with LAFB for surgery, it's important to understand:

• LAFB by itself does not increase perioperative risk
• LAFB is not listed as a contraindication to surgery in any major cardiac guidelines
• No specific preoperative management is required for isolated LAFB

Evidence-Based Approach to LAFB and Surgery

Guidelines on Conduction Abnormalities and Surgery

The ACC/AHA/HRS guidelines on bradycardia and cardiac conduction delay (2019) do not list LAFB as a condition requiring special management before surgery 1. The guidelines specifically address which conduction abnormalities warrant intervention before surgery, and LAFB alone is not among them.

Historical Perspective

While older guidelines (1996) once suggested temporary pacing for "RBBB and LAFB or LPFB (new or indeterminate)" 1, this was in the context of acute myocardial infarction, not routine surgery. Current guidelines have moved away from this approach for isolated LAFB.

Clinical Significance of LAFB

LAFB has been associated with:

• Higher prevalence of coronary artery disease (66.3% vs 54.6%) in autopsy studies 2
• Higher rates of myocardial infarction (53.3% vs 37.9%) 2
• Independent risk factor for all-cause death (HR = 1.552) and cardiac death (HR = 2.287) in long-term follow-up 2

However, these associations do not translate to increased perioperative risk that would contraindicate surgery.

Preoperative Management Algorithm for Patients with LAFB

1. Isolated LAFB with no other cardiac abnormalities:

   • No special intervention needed
   • Proceed with surgery as planned

2. LAFB with other conduction abnormalities:

   • If LAFB + RBBB (bifascicular block): Evaluate on case-by-case basis
   • If new or indeterminate bifascicular block: Consider temporary pacing wires during surgery 1

3. LAFB in specific surgical contexts:

   • For cardiac surgery: Routine placement of temporary epicardial pacing wires is recommended regardless of LAFB status 1
   • For non-cardiac surgery: No special intervention needed for isolated LAFB

Important Clinical Considerations

• LAFB may be a marker of underlying cardiac disease rather than a risk factor itself
• The presence of LAFB should prompt evaluation of coronary artery disease, especially in elderly patients 2
• LAFB with symptoms (syncope, presyncope) warrants further cardiac evaluation before elective surgery

Conclusion

LAFB by itself is not a contraindication to surgery. While it may be associated with underlying cardiac disease, isolated LAFB without other conduction abnormalities does not require special preoperative management or delay of necessary surgical procedures.