2011 10-sjm ncm svt
TRANSCRIPT
How to Apply the NCM to Map the Atrial Tachycardia
Li-Wei Lo, Shih-Ann ChenOct 16, 2011
Division of Cardiology, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
Electrophysiologic Properties of Atrial Myopathy
Cellular electrophysiology Decreased maximal diastolic potential. Dominant slow response action potential. Increased triggered automaticity.
Clinical electrophysiologyAtrial refractoriness↑Regional conduction delay ↑P wave duration↑
Sins node recovery time ↑
Hordorf et al, Circulation 1976; Sanders et al, Circulation 2003, 2004
Abnormal Electrograms of Atrial Myopathy
Number and duration of double
potential ↑
Fractionated potential ↑
Regional and global atrial voltage ↓
Sanders et al, Circulation 2003
CHF ControlCHF Control
Atrial Electrical Voltage in Heart Failure
Atrial remodeling in CHF: Structural changes, abnormalities of conduction, sinus node dysfunction, increased refractoriness
Sanders et al, Circulation 2004
Bipolar voltage mapping of atrium in SND pt and control
Regional bipolar mean voltage of right atrium
Atrial Electric Voltage in Sinus Node Disease
SNDControl
LVZ
Control (No LVZ)
SND (Wide distributed LVZ)
SND is associated with diffuse atrial remodeling: Structural changes, conduction abnormlaities, increased RA ERP
AVNRT
0.001.00
2.003.00
4.005.00
6.007.00
8.009.00
10.00
-4 -3.7
-3.4
-3.1
-2.8
-2.5
-2.2
-1.9
-1.6
-1.3 -1 -0
.7-0
.4-0
.2-0
.05
AVNRT
Fre
qu
ency
AT
0.001.00
2.003.00
4.005.006.00
7.008.00
9.0010.00
-4 -3.7
-3.4
-3.1
-2.8
-2.5
-2.2
-1.9
-1.6
-1.3 -1 -0
.7-0
.4-0
.2-0
.05
AT
Fre
qu
ency
AF
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
-4 -3.7
-3.4
-3.1
-2.8
-2.5
-2.2
-1.9
-1.6
-1.3 -1 -0
.7-0
.4-0
.2-0
.05
AF
Fre
qu
ency
AFL
0.001.00
2.003.00
4.005.006.00
7.008.00
9.0010.00
AFL
Fre
qu
ency
<-0.3 mV
<-0.3 mV<-0.3 mV
<-0.3 mV
Lin and Chen, JCE 2005
AVNRT AT
AFLAF
Voltage Frequency Distribution of the Entire Atrium in Different Atrial Tachyarrhythmia
Noncontact Mapping using a multiple electrical array to map arrhythmia with a beat-to-beat method
NCM Mapping
9 Fr Catheter
64 insulated wires as noncontact unipolar
electrodes
Mechanism of Tachycardia
Focal tachycardia: Focal tachycardia: Site of the origin is mapped Site of the origin is mapped as the earliest site of activation. Pacing at the as the earliest site of activation. Pacing at the site results in identical morphology to that of the site results in identical morphology to that of the tachycardia.tachycardia.
Reentrant tachycardia: Reentrant tachycardia: A slow pathway is a A slow pathway is a good target for ablation. Often undetectable. good target for ablation. Often undetectable. Origin of the tachycardia needs to be Origin of the tachycardia needs to be determined as the exit site from slow conduction.determined as the exit site from slow conduction.
Polarity Reversal
(Swartz JF. et al. Circulation. 1993;87:487-499)
Dragging of Catheter
Unipolar Bipolar
(Ideker et al. PACE 1989;12:456-478)
Unipolar Electrode
PVCPVC **
Electrophysiological Characteristics of Focal AT
• The regular atrial activation from atrial areas with centrifugal spread (Saoudi et al., Working Group Guideline, JCE 2001).
Definition and Clinical Presentation
• The atrial rate is less than 250 beats/min and discrete P waves separated by isoelectric intervals (Saoudi et al., Working Group Guideline, JCE 2001).
Mechanisms (Chen et al. Circulation 1994)
• Abnormal or enhanced automaticity• Triggered Activity (delayed afterdepolarization)• Microreentry
Surrounding tissue without anisotropic conduction
QS pattern
Hypothesis: Wavefront Propagation during AT
Wrap-around Effect (+)
Multi-component pattern
Wrap-around Effect (-)
Surrounding tissue with anisotropic conduction
Noncontact Mapping of Focal AT
Higa and Chen, Circulation 2004;109:84-91
Atrial Cardiomyopathy in Atrial Tachycardia
Isochronal Map
Breakout Site
II
Origin(Low Voltage)
Preferential Conduction(Low Voltage)
Contact Unipolar
Noncontact Unipolar
50ms
O
P
IVC
BO
Higa and Chen, Circulation 2004;109:84-91
Substrate Property of AT Origin and Breakout Site
AT Origin
AT Breakout
Border zone
(43.5%)
LVZ(21.7%)
Outside LVZ
(34.8%) LVZ( 8.7%)
Border zone
(21.7%)
Outside LVZ
(69.6%)
CT
SVC
IVC
LVZ
IVC
*
CT
SVC
IVC
LVZ
CT
*
Higa and Chen, Circulation 2004;109:84-91
Effect of Adenosine to Focal AT (1)
Shifting AT Origin LocationHiga and Chen, J Cardiovasc Electrophysiol 2004;15:1387-1393
Before Adenosine 3mg Adenosine 6mg
Effect of Adenosine to Focal AT (2)
Decreasing Electrogram VoltageHiga and Chen, J Cardiovasc Electrophysiol 2004;15:1387-1393
Before Adenosine 6mg
Seidl et al., PACE 2003;26 (Pt1):16-25
Isopotential Map and Unipolar EG in NCM
1. Narrow, sharp ring with center white spot.
2. QS unipolar EG with a rapid dV/dt.
1. Broad ring with litte or no white spot in the center
2. Low amplitude, broad and smooth QS morpohlogy, followed by a 2nd rapid dV/dt.
Isopotential Map and Unipolar EG in NCM
1. Broad ring of colors2. Low amplitude, fractionated
waveform followed by endocardial breakthrough, gradual dV/dt.
Seidl et al., PACE 2003;26 (Pt1):16-25
1. RFCA is successful in Group 1 and 2 AT and failed in 2 of 3 ATs in Group 3.
2. Ablation success is associated with the characteristics of isopotential maps and unipolar EG morphologies.
Catheter Ablation of Nonsustained Focal AT
Wieczorek et al., Europace 2011;13:876-82
Catheter ablation of non-sustained AT using the NCM system is safe and long
term outcome is good
Using NCM to Characterize the Origin of AT
Narita and Yamaguchi, Circ J 2010;74:59-65
Using NCM to Characterize the Origin of AT
Narita and Yamaguchi, Circ J 2010;74:59-65
Earley and Schilling, JACC, 2006:485-491
Conclusion:The accuracy of the reconstructed EG is poor > 40 mm away from the center of the array, particularly during AF.
Limitations of Noncontact Mapping
Conclusions
Focal AT Focal AT originates from a small area and spreads originates from a small area and spreads out to the whole atriumout to the whole atrium through a preferential through a preferential conduction.conduction.
The site of focal AT locates at the disease atria and The site of focal AT locates at the disease atria and 78.6% of the AT originating from 78.6% of the AT originating from LVZ or border zone LVZ or border zone around the LVZaround the LVZ..
Adenosine-induced AT termination: Associated with Adenosine-induced AT termination: Associated with shifting AT origin, decreasing EG voltage, shifting AT origin, decreasing EG voltage, disappearance of focal activationdisappearance of focal activation..
Application of RF energy on Application of RF energy on origin (QS pattern) origin (QS pattern) or or proximal portion of preferential conduction proximal portion of preferential conduction effective effective in eliminating focal AT.in eliminating focal AT.
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