Mouse EPS Protocol
Begin by determining atrial and ventricular capture thresholds.
Start at 0.1 V (with good catheter position capture threshold should be 0.1 V) and then place output at 0.3 V or twice diastolic threshold if 0.2 V.
Sinus Node Recovery Times
Deliver atrial pace at drive cycle lengths of 150, 120 and 100 ms for 15 seconds each.
AV Nodal Conduction
Deliver atrial burst pacing starting at 150 ms and decrement by 10 ms down to AV Wenckebach cycle length. Then increase by 5 ms to see if there is either 1:1 conduction or there is still Wenckebach.
Continue delivering atrial burst pacing and decrement by 10 ms down to 2:1 conduction and then increase by 5 ms to see if there is still 2:1 conduction or Wenckebach.
AV Nodal Effective Refractory Period
Start with a drive cycle of 150 ms with an S2 coupled at 145 ms and bring in S2 by 5 ms until there is no more conduction to the ventricle.
If the AV nodal Wenckebach cycle length is < 120 ms there repeat the protocol with a drive cycle of 120 ms with an S2 coupled at 115 ms.
Atrial Effective Refractory Period
Begin with a drive cycle of 150 ms with an S2 coupled at 70 ms and bring in S2 by 10 ms until there is loss of atrial capture, then bring out S2 by 5 ms until atrial capture returns.
Repeat the protocol with drive cycles of 120 ms and 100 ms beginning with an S2 coupled at 70 ms.
Atrial Double Extrastimuli:
Begin with a drive of 150 ms with an S2 coupled at 70 ms and an S3 also coupled at 70 ms. Bring in S3 by 10 ms until it is just below AERP and then bring in S2 by 10 ms until it is below AERP as well.
Atrial Triple Extrastimuli:
Begin with a drive cycle of 150 ms with an S2 coupled at 70 ms, an S3 coupled at 70 ms and an S4 also coupled at 70 ms. Bring in S4 by 10 ms until it is just below AERP and then repeat the protocol as above with atrial doubles.
Atrial Burst Pacing
Deliver atrial pacing with a train of 28 S1 at a cycle length of 50 ms followed by four extrastimuli with a coupling interval of 30 ms for about 20 seconds with a pause of one second in between trains. Then repeat the protocol with a train of 48 S1 for 20 more seconds followed by 20 seconds more with a train of 8 S1.
Retrograde AV Conduction
Begin at a cycle length of 150 ms and increment by 10 ms steps until there is 1:1 VA conduction or the pace cycle length is greater than the sinus cycle length.
Ventricular Burst Pacing
Begin at a cycle length of 150 ms and pace for one screen then decrement the burst cycle length by 10 ms and repeat down to a cycle length of 50 ms.
Right Ventricular Effective Refractory Period
Begin with a drive cycle of 150 ms with an S2 coupled at 70 ms and bring in S2 by 10 ms until S2 fails to capture and then bring S2 out by 5 ms to find the refractory period.
Repeat the protocol with a drive cycle of 120 ms and then 100 ms coupled with an S2 at 70 ms.
Ventricular Double Extrastimuli:
Start with a drive cycle of 150 ms (or 120 ms if the sinus cycle length is less that 150 ms) with an S2 coupled at 70 ms and an S3 coupled at 70 ms. Bring in S3 by 10 ms decrements down to 50 ms and then bring in S2 by 10 ms decrements. Bring in S3 and the S2 by 10 ms decrements until S2 is refractory.
Ventricular Triple Extrastimuli:
Start with the same drive as used for the ventricular double extrastimuli with and S2, S3 and S4 coupled at 70 ms each. Repeat the protocol as above for ventricular double extrastimuli starting with S4 and bring in each extrastimuli down to 50 ms. Consecutively bring in each extrastimuli by 10 ms until S2 is refractory.
Ventricular Burst Pacing
Begin with a drive train of 28 stimuli at a cycle length of 50 ms followed by four extrastimuli coupled at 30 ms each for about 20 seconds. Now increase the number of the stimuli in the drive train to 48 and repeat the protocol for 20 seconds more. Finally, decrease the number of stimuli in the drive train to 8 and repeat the protocol for the last 20 seconds.
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