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EP STUDYMINIMUM PROTOCOL

WEVE TALKED ABOUTEQUIPMENTPATIENT PREPARATIONRELEVANT ANATOMYCATHETERS and PLACEMENTBASIC INTERVALSTESTS OF SN FUNCTION

AND NOWEQUIPMENTPATIENT PREPARATIONRELEVANT ANATOMYCATHETERS and PLACEMENTBASIC INTERVALSTESTS OF SN FUNCTION

ATRIAL and VENTRICULAR EXTRASTIMULUS TESTINGREFRACTORY PERIODSGAP INCREMENTAL PACINGMINIMUM PROTOCOL FOR DIAGNOSTIC EPS

Extrastimulus testing

5Drive train with a single extra stimulus

8 paced beat drive train EP steady stateExtrastimulus(Coupling interval)

5Coupling interval

Extra stimuli

S1S1S1S1S1S1S1S1S2SensedDRIVETRAIN

S1S1S1S1S1S1S1S1S2SensedDRIVETRAIN

S3

SingleDoubleTriple

6Coupling interval: time between extra stimui (S2) after train pacing

Atrial Extrastimulus testing Dynamic properties of AVN and HPS conductionAVN and RA refractory periods

Atrial Extrastimulus testing Dynamic properties of AVN and HPS conductionAVN and RA refractory periods

Dual AVN physiology

Atrial Extrastimulus testing Dynamic properties of AVN and HPS conductionAVN and RA refractory periods

Dual AVN physiology

Arrhythmia induction

S2 with long coupling interval

Conduction at fairly constant velocity

A2H2 equal or slightly more than A1H1

A1H1 80 ms ~ A2H2 95 ms

S1A1 ~ S2A2 ~ 55 ms

H1V1 ~ H2V2 ~ 50 ms

S2 with short coupling interval

Slowing of Conduction

A1H1 < A2H2

A1H1 80 msA2H2 140 ms

S2 with shorter coupling interval

Blocked AES at AVN

Ventricular Extrastimulus testing Retrograde conduction over HPS and AVN

Accessory pathway conduction

Arrhythmia induction

Ventricular Extrastimulus testing Retrograde conduction over HPS and AVN

Accessory pathway conduction

Arrhythmia induction

Stimulation at RV apex conventionally RV apex Stim distal RBB HPS AVN RA

S2 with long coupling interval

H buried in VV1A1 almost equal to V2A2

Earliest atrial activation in HBEAtleast 30 ms before HRAProximal-to-distal CS activationCONCENTRIC ATRIAL ACTIVATION

S2 with short coupling interval

S2 with shorter coupling interval

S2 with short coupling interval with short drive cycle length

Blocked VES at AVN

VA block

Differs with ES coupling interval Drive cycle length

S2 with short coupling interval

Tissue latency in local evoked response

Occurs just above the tissue refractory period

Even shorter coupling interval

Blocked VES locally at RV apex

Loss of ventricular capture

Ventricular Extrastimulus testing Other Normal responsesNo VA conduction at allAtropine, IsoprenalineNo VA conduction despite drugs

Ventricular Extrastimulus testing Other Normal responsesNo VA conduction at allAtropine, IsoprenalineNo VA conduction despite drugs

Retrograde exit site from AV node maybe near CS ostium rather than HBE earliest atrial activation at Proximal CS

Ventricular Extrastimulus testing Other Normal responsesNo VA conduction at allAtropine, IsoprenalineNo VA conduction despite drugs

Retrograde exit site from AV node maybe near CS ostium rather than HBE earliest atrial activation at Proximal CS Maneuvers to prove accessory pathway

Refractory periods

EFFECTIVE Refractory PeriodERP of a tissue

EFFECTIVE Refractory PeriodERP of a tissue (or a structure)

EFFECTIVE Refractory PeriodERP of a tissue (or a structure) is the LONGEST coupling interval that fails to capture the tissue

EFFECTIVE Refractory PeriodERP of a tissue (or a structure) is the LONGEST coupling interval that fails to capture the tissue (or be conducted over the structure)

FUNCTIONAL Refractory PeriodFRP of a tissue (or a structure) is the SHORTEST output coupling interval that can be elicited from a tissue (or structure) by any input interval

FUNCTIONAL Refractory PeriodFRP of a tissue (or a structure) is the SHORTEST output coupling interval that can be elicited from a tissue (or structure) by any input interval

S1-A1-H1-V1S2-A2-H2-V2AVNHPSAV conduction system

RELATIVE Refractory PeriodRRP of a tissue (or a structure) is the input interval at which the output interval just begins to differ from input interval

RELATIVE Refractory PeriodRRP of a tissue (or a structure) is the input interval at which the output interval just begins to differ from input interval

This is the point at which Latency or Decremental conduction begins to occur

Least commonly measured

In all tissues, ERP and FRP are length-dependentSo, measured using atleast 2 different drive cycle lengths

AVNERP

Longest A1A2 interval that fails to capture HB

A1A2 maybe longer than S1S2 due to tissue latency

AVNFRP

Shortest H1H2 in response to any A1A2 interval

AVNRRP

Longest A1A2 interval at which A2H2 exceeds A1H1

Normal range of refractory periods (ms)ERP AtriaERP AVNFRP AVNERP HPSERP V150-350 230-430330-530330-450190-290

*Denes, Akhtar, Durrer, Josephsen series

GAP phenomena

ES conducted as LBBB

INCREMENTAL ATRIAL PACING

INCREMENTAL VENTRICULAR PACING

MINIMUM PROTOCOLBasic intervalsSNRT and CSNRTAES AVNERP AV WCLVES VERPVA WCL

Arrhythmia induction

TO BE CONTINUED.

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