Endpoint for typical flutter ablation is which of the following?

Endpoint for typical flutter ablation is which of the following?

• A. Bidirectional block along CTI
• B. Presence of AH jump with no tachycardia reinduction
• C. Decrease in heart rate
• D. Normal ECG

Answer: (A)

The main idea is that the flutter circuit relies on the cavotricuspid isthmus as the critical pathway. When ablation creates a continuous line of block across this isthmus in both directions, the reentrant circuit can no longer propagate, so typical flutter cannot reoccur. This bidirectional block is verified by pacing from either side of the ablation line and showing that conduction cannot cross the line in either direction, effectively interrupting the circuit. Other signs like an AH jump, a simple drop in heart rate, or a normal ECG after the procedure aren’t reliable endpoints for this specific ablation, because they don’t confirm that the CTI actually can't conduct in both directions.

The main idea is that the flutter circuit relies on the cavotricuspid isthmus as the critical pathway. When ablation creates a continuous line of block across this isthmus in both directions, the reentrant circuit can no longer propagate, so typical flutter cannot reoccur. This bidirectional block is verified by pacing from either side of the ablation line and showing that conduction cannot cross the line in either direction, effectively interrupting the circuit. Other signs like an AH jump, a simple drop in heart rate, or a normal ECG after the procedure aren’t reliable endpoints for this specific ablation, because they don’t confirm that the CTI actually can't conduct in both directions.