What is Pace Sense Stim?

PSS stands for Pacing, Sensing and high-frequency Stimulation for use with the Isolator® multifunctional pen. These are methods used to evaluate electrical activity within and around atrial cardiac tissue. Pacing and sensing in reference to atrial fibrillation are two methods to determine if electrical isolation, or quiescence, has been achieved.

Pace

Objective: Confirm exit block of focal stimuli from the atrial cuff to the atrium

Pre-Ablation

Using the multifunctional pen, establish atrial capture by placing the pen at various atrial cuff locations – superior, bifurcation, inferior (lateral to the proposed ablation line) documenting those that elicit a corresponding atrial pacing rate change.

Post-Ablation

Place the pen at all previously identified atrial cuff locations to confirm that they no longer provoke a corresponding atrial rate change.

Sense (optional)

Objective: Confirm entrance block of atrial cuff potentials through evaluation of baseline waveforms.

Pre-Ablation

Using the multifunctional pen, identify and record baseline ECG potentials along the left and right atrial cuff.

Post-Ablation

Reposition pen at previously identified baseline locations to confirm absence of potentials or slow potentials disassociated from left atrial activity.

Stimulate

Objective: Confirm inactivity of parasympathetic responses associated with intrinsic cardiac nervous system utilizing high-frequency stimulation (HFS).

Pre-Ablation

Using the multifunctional pen, stimulate various locations in the atrial epicardial surface, noting those sites that elicit a vagal response (significant slowing intrinsic heart rate).

Post-Ablation

Return the pen to previously identified sites to confirm that HFS no longer initiates a vagal response.

Ablate

Objective: Create precise cardiac lesions to achieve desired outcomes.

The Isolator multifunctional pen is intended to ablate cardiac tissues during cardiac surgery using radiofrequency energy when connected to the AtriCure® Ablation and Sensing Unit or for temporary cardiac pacing, sensing, recording, and stimulation during the evaluation of cardiac arrhythmias during surgery when connected to a temporary external cardiac pacemaker or recording device.  For further information, see the summary of the FDA's 510(k) clearance.