2011 10-sjm ncm svt

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


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

*


[email protected]

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

[email protected]

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

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.

Thank You For Your Attention !

2011 10-sjm ncm svt

Health & Medicine

Transcript of 2011 10-sjm ncm svt