During entrainment mapping for typical atrial flutter, pacing from which catheters could you determine concealed entrainment?

During entrainment mapping for typical atrial flutter, pacing from which catheters could you determine concealed entrainment?

• A. CS catheter
• B. Duodecapolar catheter
• C. CS or duodecapolar catheter
• D. Other catheter

Answer: (C)

Entrainment mapping tests whether your pacing site is inside the reentrant circuit by delivering pacing during the tachycardia. Concealed entrainment means you capture the circuit without altering the activation pattern outside the circuit, so the post-pacing interval matches the flutter cycle length and there’s no visible fusion on the recordings. In typical atrial flutter the macro-reentrant loop wraps around the tricuspid annulus, with critical conduction often through the cavotricuspid isthmus. The coronary sinus catheter sits along the posterior right atrium near the isthmus, and a duodecapolar catheter spans the right atrium around the circuit. Pacing from either of these catheters can enter the flutter circuit itself, yielding concealed entrainment because the pacing impulse travels within the loop and does not disrupt the outside activation pattern; the post-pacing interval equals the flutter cycle length. Pacing from catheters that are outside the circuit is less likely to produce concealed entrainment, as the impulse may not fully engage the reentrant path in the same way and can create visible fusion or a longer post-pacing interval. So, pacing from the coronary sinus catheter or the duodecapolar catheter best allows concealed entrainment in typical atrial flutter.

Entrainment mapping tests whether your pacing site is inside the reentrant circuit by delivering pacing during the tachycardia. Concealed entrainment means you capture the circuit without altering the activation pattern outside the circuit, so the post-pacing interval matches the flutter cycle length and there’s no visible fusion on the recordings.

In typical atrial flutter the macro-reentrant loop wraps around the tricuspid annulus, with critical conduction often through the cavotricuspid isthmus. The coronary sinus catheter sits along the posterior right atrium near the isthmus, and a duodecapolar catheter spans the right atrium around the circuit. Pacing from either of these catheters can enter the flutter circuit itself, yielding concealed entrainment because the pacing impulse travels within the loop and does not disrupt the outside activation pattern; the post-pacing interval equals the flutter cycle length.

Pacing from catheters that are outside the circuit is less likely to produce concealed entrainment, as the impulse may not fully engage the reentrant path in the same way and can create visible fusion or a longer post-pacing interval.

So, pacing from the coronary sinus catheter or the duodecapolar catheter best allows concealed entrainment in typical atrial flutter.