Transcript Electrophysiological study mapping study.

ELECTROPHYSIOLOGICAL STUDYMAPPING TECHNIQUES
DR HIMAL RAJ.M
SR CARDIOLOGY
Contents
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History
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Electrophysiological mapping
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Mapping techniques
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Mapping sites
History
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Josephson et al- endocardial catheter mapping of
VT
Huang et al,1985- radiofrequency catheter
ablation
Sternick EB, Gerken LM, Vrandecic MO. Appraisal of ‘Mahaim’ automatic tachycardia. J Cardiovasc Electrophysiol 2002;13:244–9.
Electrophysiological mapping
Mapping
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to localize site of origin of abnormal beats or
to identify tachycardia circuit in case of reentrant arrhythmias
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Mapping procedures
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Pace Mapping
Activation Sequence Mapping
Voltage mapping( Substrate / Fractionated electrogram )
Entrainment Mapping
Miscellaneous
Klein LS, Shih H-T, Hackett FK, Zipes DP, Miles WM. Radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease. Circulation 1992; 85: 1666–74
Pace mapping
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to locate tachycardia sources by stimulating at different
endocardial sites
to reproduce clinical tachycardia
characteristics
Manipulation of mapping catheter to region of origin of
tachycardia
Pace at this site at same cycle length as tachycardia
Greater the concordance b/w tachycardia and morphology
during pacing - closer exit site
Klein LS, Shih H-T, Hackett FK, Zipes DP, Miles WM. Radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease. Circulation 1992; 85: 1666–74
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Look for 12/12 match
More useful in ventricular tachycardia as QRS morphology
easier to compare
Allows to home in on region of interest - cannot pinpoint site
for ablation
Does not require tachycardia to sustain over a longer time
Pace Map 12/12 Match
Klein LS, Shih H-T, Hackett FK, Zipes DP, Miles WM. Radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease. Circulation 1992; 85: 1666–74
Activation sequence mapping
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Required to pinpoint focus of tachycardia
During tachycardia - mapping catheter explores
endocardium - to identify site where earliest
electrogram relative to a fixed reference is
recorded
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Suitable site
 Local
electrogram precedes any other activity
 One from which any movement results in a later
electrogram
 One at which unipolar electrogram shows a sharp initial
negative deflection
Klein LS, Shih H-T, Hackett FK, Zipes DP, Miles WM. Radiofrequency catheter ablation of ventricular tachycardia in patients without structural heart disease. Circulation 1992; 85: 1666–74
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To create activation map- points are color-coded
white and red for earliest electrical activation areas
orange, yellow, green, blue and purple for
progressively delayed activation areas
Between these points-colors are interpolated and
adjoining triangles are colored with these
interpolated values
Propagation map
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Activation sequence in mapped chamber can also
be represented as propagation map
in which whole chamber is blue and electrical
activation waves are seen in red, spreading
throughout chamber as a loop(manually done in
ENSITE)
Substrate( Voltage) Mapping
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Scarred Myocardium has Low Voltage
 0.5
mV or Less - Dense Scar
 0.5 – 1.5 mV - Borderline Zone
 > 1.5 mv - Normal area
McClelland JH, Wang X, Beckman KJ, Hazlitt HA, Prior MI, Nakagawa H et al. Radiofrequency catheter ablation of right atriofascicular (Mahaim) accessory
pathways guided by accessory pathway activation potentials. Circulation 1994;89:2655–66.
Voltage mapping
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Also color-coded
Red as lowest amplitude and orange, yellow, green,
blue and purple indicating progressively higher
amplitudes
Myocardial scars are seen as low voltage - and their
delineation may help in understanding location of
arrhythmia
Entrainment mapping
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Allows confirmation of Reentry
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Allows localization of circuit and isthmus
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Entrainment is a continuous resetting of a reentrant
circuit by a series of stimuli
McClelland JH, Wang X, Beckman KJ, Hazlitt HA, Prior MI, Nakagawa H et al. Radiofrequency catheter ablation of right atriofascicular (Mahaim) accessory
pathways guided by accessory pathway activation potentials. Circulation 1994;89:2655–66.
Criteria for Entrainment
1.
2.
3.
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Constant fusion during overdrive pacing except for last paced beat which
is entrained but not fused
Progressive fusion during overdrive pacing
Localized conduction block to a site for 1 paced beat associated with
interruption of tachycardia, followed by activation of that site by next
paced beat from a different direction and with a shorter conduction time
During pacing at 2 different rates during tachycardia- change in
conduction time and EGM morphology at electrode recording site
(equivalent of demonstrating progressive fusion - second criterion - with
intracardiac electrogram recordings).
McClelland JH, Wang X, Beckman KJ, Hazlitt HA, Prior MI, Nakagawa H et al. Radiofrequency catheter ablation of right atriofascicular
(Mahaim) accessory pathways guided by accessory pathway activation potentials. Circulation 1994;89:2655–66
Entrainment results in a fusion complex
Pacing stopped-last one entrained but goes round
circuit-morphology similar to original rhythm
If pacing CL progressively shortened circuit is
invaded to a greater extent-fusion increases
A premature paced beat collides with head and tail-fails
to propagate
Next beat is purely paced and R is activated from a
different direction
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Manifest entrainment- demonstration of resetting
with fusion
Concealed entrainment- failure to demonstrate
fusion but PPI equal to tachycardia cycle length-site
protected isthmus
PPI equal to TCL (within 20-30 ms)if pacing site
within reentrant circuit
Post pacing interval-interval b/w last pacing
stimulus that entrained tachycardia and next
recorded EGM at pacing site
Manifest Entrainment with
Fusion
Premature impulse
invade tachycardia
circuit.In antidromic
direction it collides and
extinguishes reentrant
wavefront. In
orthodromic direction it
creates a new
wavefront(resets).
Concealed Fusion
Antidromic
wave front
does not
contribute much
to morphology
of tachycardia
beat
Area of slow conduction : Isthmus
Concealed Fusion
Post Pacing Interval
If paced from the critical
Isthmus PPI = TCL
Determining Pacing Site
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How to Determine if the Pacing Site is Within the Circuit
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Post Pacing Interval
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QRS Configuration during Entrainment
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S-QRS Interval During Entrainment with Concealed Fusion
Stevenson Et al. Entrainment Techniques for Mapping Atrial and Ventricular Tachycardias. JCE 6(3) March 1995; 201-216
Post Pacing Interval
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Pace at rates slightly faster than TCL - measure local activation
time from last paced beat to local EGM at pacing site
Indication of proximity of pacing site to reentry circuit - time
from stimulus to next nonstimulated depolarization
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PPI for ischemic VT should be within 30ms
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20ms in atrial flutter circuits
McClelland JH, Wang X, Beckman KJ, Hazlitt HA, Prior MI, Nakagawa H et al. Radiofrequency catheter ablation of right atriofascicular (Mahaim) accessory
pathways guided by accessory pathway activation potentials. Circulation 1994;89:2655–66.
Types of mapping site
Types of Mapping Sites
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Remote Bystanders
Adjacent Bystanders
Outer Loop Sites
Exit Site
Central, Proximal, and Inner Loop Sites
Albert L. Waldo. Heart Rhythm (2004) 1, 94–106
Remote Bystander
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Entrains with QRS fusion
Post Pacing Interval
exceeds the Tachycardia
Cycle length
Vishal Luther, Michael Koa-Wing. Ventricular Tachycardia Ablation in the Post Infarct
Patient. http://bhrs.com/editorial-vt-ablation-in-the-post-infarct-patient
Adjacent Bystander
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Pacing entrains tachycardia
with concealed fusion.
PPI does not approximate TCL
S-QRS interval during
entrainment does not match
electrogram QRS interval
during tachycardia
Vishal Luther, Michael Koa-Wing. Ventricular Tachycardia Ablation in the Post Infarct Patient. http://bhrs.com/editorial-vt-ablation-in-the-post-infarct-patient
Outer Loop Sites
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PPI matches TCL
Pacing at these sites
produce QRS fusion
Vishal Luther, Michael Koa-Wing. Ventricular Tachycardia Ablation in the Post Infarct Patient. http://bhrs.com/editorial-vt-ablation-in-the-post-infarct-patient
Exit Site
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Pacing produces
entrainment with concealed
fusion
PPI matches TCL
S-QRS interval < 30% of
TCL
Stevenson Et al. Entrainment Mapping. JACC 29 (6) May 2007: 1180-9
Central, Proximal, and Inner Loop Sites
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As the pacing site is moved further from
the exit to more proximal sites the SQRS interval increases.
If the S-QRS interval is
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>31-50% of the tachycardia cycle length
they are designated as central sites
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51-70% of the tachycardia cycle length
they are designated as proximal sites
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>70% of the tachycardia cycle length they
are designated as Inner Loop sites
Stevenson Et al. Entrainment Mapping. JACC 29 (6) May 2007: 1180-9
McClelland JH, Wang X, Beckman KJ, Hazlitt HA, Prior MI, Nakagawa H et al. Radiofrequency catheter ablation of right atriofascicular (Mahaim) accessory
pathways guided by accessory pathway activation potentials. Circulation 1994;89:2655–66.
Advanced mapping systems
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Electro anatomic mapping-CARTO system
 Metal
coil placed in a magnetic field
 Catheter contains a location sensor in tip
 3D map created by placing catheter in known anatomic
positions
 Local electrogram at each point superimposed on
anatomical map to give a color coded activation map
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Non contact mapping-ENSITE
 Multi
electrode array probe with 64 non contact
electrodes
 Endocardial boundaries defined with conventional
mapping catheter
 3D Endocardial potential map created from single
cardiac cycle
McClelland JH, Wang X, Beckman KJ, Hazlitt HA, Prior MI, Nakagawa H et al. Radiofrequency catheter ablation of right atriofascicular (Mahaim) accessory
pathways guided by accessory pathway activation potentials. Circulation 1994;89:2655–66.
Basket catheter Ensite array
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Magnetic navigation system
 Ablation
catheter guided and positioned by magnetic
fields to a desired site within cardiac chamber
3D anatomical mapping system
Newer techniques -- 3D
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Creating and displaying 3D image of heart chambers
Displaying in multiple colors activation sequence of
electrical signals of heart chambers
Visualizing physical point of origin of arrhythmia
accurately
ADVANTAGE OF 3D
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Managing complex arrhythmias, postoperative
cases with altered anatomy and single beat nonsustained arrhythmias
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ENSITE
CARTO
RMP
Site of placement of electrodes
Anatomical shell
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Following selection of anatomic reference - mapping
catheter positioned in mapping chamber under
fluoroscopic guidance
Catheter initially positioned at known anatomic
points - serve as landmarks for electroanatomic map
 eg:to
CS os
map right atrium, points such as SVC, IVC, His and
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Catheter tip advanced slowly along different walls
Analysis of anatomic position of these points generate real-time 3-D models on a monitor display
Selected points connected by lines to form several
adjoining triangles in a global model of chamber
RA anatomical chamber
LA anatomical mapping
LA anatomical mapping
Bi-atrial anatomical chamber
LV Anatomical shell
Biatrial anatomical chamber
LA mapping :-Earliest activation from the
RSPV
LA mapping :- Earliest activation from the
RSPV
RVOT VT
activation
CARTO
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Combined electroanatomic means of mapping
cardiac arrhythmias
Patient is positioned over a tripod emitting three
electromagnetic waves at unique frequencies
Each beam is registered by one of three specifically
tuned coils embedded in mapping catheter tip to
specify location in 3D space
CARTO
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An electrogram recorded at that site is thereby
archived within that positional context
Direction of catheter tip, along with its pitch, yaw, and
roll altitude creates a orientation vector
Local tissue activation at each successive recording
site produces activation maps within framework of
acquired surrogate geometry
CARTO principle magnetic mapping
Carto catheter position
Carto
CARTO view from all postions
RMP Mapping System
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based on ultrasound-distance ranging.
Real-time Position Management
Three catheters-fitted with microtransducerspositioned into right ventricle and coronary sinuswith a third catheter used as a roving ablation or
mapping catheter
Newer Modalities
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NavX
RHYTHMIA
REMOTE NAVIGATION SYSTEMS
REAL TIME IMAGING
M