CT of the Left Atrium and Pulmonary Veins before …eradiology.bidmc.harvard.edu/LearningLab/cardio/Chen.pdfCT of the Left Atrium and Pulmonary Veins before Radio- ... diameter of

Vincent Chen, MS IVGillian Lieberman, MD

CT of the Left Atrium and CT of the Left Atrium and Pulmonary Veins before RadioPulmonary Veins before Radio--

Frequency Catheter Ablation for Frequency Catheter Ablation for AtrialAtrial

FibrillationFibrillation

Vincent Chen, Harvard Medical School Year IVVincent Chen, Harvard Medical School Year IVGillian Lieberman, MDGillian Lieberman, MD


September 2008


2

AgendaAgenda

Our patientOur patient

AtrialAtrial

fibrillation and the role of the pulmonary fibrillation and the role of the pulmonary

veinsveins

PrePre--RFCA imaging with CT RFCA imaging with CT ––

epicardialepicardial

and and

endocardialendocardial

reconstructions, measurement of reconstructions, measurement of geometry geometry

Radiofrequency catheter ablation Radiofrequency catheter ablation ––

technique, technique,

complications, challengescomplications, challenges


3

Our PatientOur Patient

75 75 yoyo

M w/ longstanding M w/ longstanding atrialatrial

arrhythmiasarrhythmias

Refractory to medical management Refractory to medical management ––

failed failed dofetilidedofetilide, , quinidinequinidine, , amiodaroneamiodarone, , sotalolsotalol

Chronically Chronically anticoagulatedanticoagulated

and rate controlled, has and rate controlled, has pacemakerpacemaker

Recently suffering from increasingly severe shortness of Recently suffering from increasingly severe shortness of breath associated with fatiguebreath associated with fatigue

Noted to be in Noted to be in atrialatrial

tachycardia, pacemaker attempted tachycardia, pacemaker attempted to overdrive pace, but failedto overdrive pace, but failed

Echocardiogram showed reduced ejection fraction, Echocardiogram showed reduced ejection fraction, consistent with worsening symptomsconsistent with worsening symptoms


4

AtrialAtrial


Most common sustained cardiac arrhythmiaMost common sustained cardiac arrhythmia

Most common cardiac arrhythmia requiring Most common cardiac arrhythmia requiring hospitalizationhospitalization

Occurs when ectopic electrical foci Occurs when ectopic electrical foci ““firefire”” independentlyindependently

Major complications:Major complications:

Hemodynamic compromise Hemodynamic compromise ––

rapid ventricular rate can cause rapid ventricular rate can cause hypotension, chronic poorly controlled tachycardia can cause hypotension, chronic poorly controlled tachycardia can cause ventricular dysfunctionventricular dysfunction

Thrombi may form and Thrombi may form and embolizeembolize, resulting in significant , resulting in significant morbidity/mortality from strokemorbidity/mortality from stroke


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Pulmonary Veins and AFPulmonary Veins and AF

Thus, we can attempt to interrupt Thus, we can attempt to interrupt conduction pathways that lead to conduction pathways that lead to atrialatrial

fibrillation, electrically fibrillation, electrically ““disconnectingdisconnecting””

the pulmonary the pulmonary vein from the atriumvein from the atrium

Surgical management: modified Surgical management: modified maze procedure maze procedure ––

series of series of atrialatrial

incisionsincisions

NonNon--surgical management: RFCA surgical management: RFCA of distal pulmonary veinsof distal pulmonary veins

Ectopic foci are often found in the Ectopic foci are often found in the distal pulmonary veins*distal pulmonary veins*

* Jais

P, Haissaguerre

M, Shah DC, et al. A focal source of atrial

fibrillation treated by discrete radiofrequency ablation. Circulation 1997;95:572-576

L atrium

Pulmonary Veins


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RFCA for RFCA for AtrialAtrial


Under fluoroscopic guidance, Under fluoroscopic guidance, a catheter with an ablation a catheter with an ablation electrode is guided up the electrode is guided up the IVC, across the IVC, across the atrialatrial

septum, septum,

then to the pulmonary veinsthen to the pulmonary veins

The specific ectopic focus or The specific ectopic focus or the entire circumference of the entire circumference of the vein is ablatedthe vein is ablated

Frequently, to reduce need Frequently, to reduce need for a repeat procedure, all for a repeat procedure, all pulmonary vein pulmonary vein ostiaostia

are are

empirically ablatedempirically ablated


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Complications of RFCAComplications of RFCA

Pulmonary vein dissectionPulmonary vein dissection

AtrialAtrial

or pulmonary vein perforationor pulmonary vein perforation

Pulmonary vein Pulmonary vein stenosisstenosis**

Lengthy fluoroscopic time poses radiation risk Lengthy fluoroscopic time poses radiation risk to patient and physiciansto patient and physicians

There has been at least one case of radiation There has been at least one case of radiation dermatitis following fluoroscopy for RFCA**dermatitis following fluoroscopy for RFCA**

* Saad

EB, Marrouche

NF, Saad

CP, et al. Pulmonary vein stenosis

after catheter ablation of atrial

fibrillation: emergence of a new clinical syndrome. Ann Intern Med 2003; 138634-638.

** Nahass

GT. Acute radiodermatitis

after radiofrequency catheter ablation. J Am Acad

Dermatol

1997; 36:881-884


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Challenges of RFCAChallenges of RFCA

Pulmonary vein anatomy is quite variablePulmonary vein anatomy is quite variable

The The ““normalnormal””

pulmonary vein anatomy is composed of pulmonary vein anatomy is composed of four pulmonary veinsfour pulmonary veins

However, common However, common ostiaostia

or extra veins are commonor extra veins are common

Radiofrequency energy is ideally applied very close to Radiofrequency energy is ideally applied very close to the the venoatrialvenoatrial

junctionjunction

Reduce risk of Reduce risk of stenosisstenosis

––

the further the ablation is from the the further the ablation is from the ostiumostium, the greater the chance of , the greater the chance of stenosisstenosis

Reduce risk that portion of pulmonary vein that remains Reduce risk that portion of pulmonary vein that remains electrically attached to atrium may contain ectopic focielectrically attached to atrium may contain ectopic foci


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Value of PreValue of Pre--RFCA ImagingRFCA Imaging

Imaging helps address these challenges, reducing Imaging helps address these challenges, reducing complicationscomplications

Imaging tells usImaging tells us

Is the anatomy normal?Is the anatomy normal?

What is the What is the ostialostial

diameter of each vein and how far diameter of each vein and how far is it to the first branch?is it to the first branch?

Are there any extra pulmonary veins?Are there any extra pulmonary veins?


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PrePre--RFCA ImagingRFCA Imaging

In the past, attempts were made to In the past, attempts were made to define the pulmonary vein define the pulmonary vein ostiaostia

by by injecting contrast into the L atrium injecting contrast into the L atrium and attempting to visualize contrast and attempting to visualize contrast material that refluxed into the material that refluxed into the pulmonary veins (pulmonary pulmonary veins (pulmonary venographyvenography))

This is difficult, as blood flows the This is difficult, as blood flows the opposite wayopposite way

Furthermore, the 2D nature of Furthermore, the 2D nature of fluoroscopy doesnfluoroscopy doesn’’t allow accurate t allow accurate 3D assessment3D assessment

Thus, we often use CT or MR Thus, we often use CT or MR --

often CT as patients frequently often CT as patients frequently have pacemakers and thus cannot have pacemakers and thus cannot receive MR imagingreceive MR imaging


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MultiMulti--Detector Row CTDetector Row CT

L atrium

L ventricle

R ventricle

PACS, BIDMC

C+ axial CT C+ axial CT

C+ axial CT C+ axial CT


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EpicardialEpicardial

((ExtraatrialExtraatrial) VR Views) VR Views

A 3D model of the left atrium and the pulmonary veins is A 3D model of the left atrium and the pulmonary veins is created and can be manipulated to better understand the 3D created and can be manipulated to better understand the 3D structurestructure

Note this patient has a R middle pulmonary vein!Note this patient has a R middle pulmonary vein!

PACS, BIDMC

3D reformation of C+ axial CT 3D reformation of C+ axial CT 3D reformation of C+ axial CT


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EndocardialEndocardial

((IntraatrialIntraatrial) VR) VR


reconstructions allow us to open up the reconstructions allow us to open up the atria and look from the insideatria and look from the inside

L superior pulmonary vein

L inferior pulmonary vein

PACS, BIDMC

R superior pulmonary vein

R middle pulmonary vein

R inferior pulmonary vein

3D reformation of C+ axial CT3D reformation of C+ axial CT


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VR (contVR (cont’’d)d)

We can actually We can actually ““traveltravel””

through veins and imagine through veins and imagine what the ablating catheter seeswhat the ablating catheter sees

PACS, BIDMC

3D reformation of C+ axial CT


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Measurement of Measurement of ostialostial

diametersdiameters on on endoluminalendoluminal

viewsviews

EndoluminalEndoluminal

views can be views can be used to measure geometry of used to measure geometry of the vessels, show vein the vessels, show vein orientation, show where orientation, show where veins branch, etc.veins branch, etc.

PACS, BIDMC

3D reformation of C+ axial CT 3D reformation of C+ axial CT

L superior pulmonary vein

L inferior pulmonary vein

R superior pulmonary vein

R middle pulmonary vein

R inferior pulmonary vein


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Measurement of Measurement of ostialostial

diametersdiameters on on multiplanarmultiplanar

reformationsreformations

OstialOstial

diameters can also diameters can also be measured by be measured by examining curved examining curved reformations, reformations, demonstrating the demonstrating the narrowing of the lumen narrowing of the lumen of a vesselof a vessel

Or on orthogonal cross Or on orthogonal cross sectionssections

Vessel lumen

Diameter

PACS, BIDMC

Multiplanar

reformation of C+ axial CT

Pulmonary vein

Orthogonal cross-section reformation of C+ axial CT


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Summary: CT mapping of LA and Summary: CT mapping of LA and PV anatomy in RFCA for AFPV anatomy in RFCA for AF

RFCA is increasingly used to treat RFCA is increasingly used to treat atrialatrial

fibrillationfibrillation

CT provides the CT provides the electrophysiologistelectrophysiologist

with extrawith extra--

and intraand intra--atrialatrial anatomic information prior to the procedureanatomic information prior to the procedure

CT improves ease of visualizing number, position and location CT improves ease of visualizing number, position and location of pulmonary veins, reducing risk of complicationsof pulmonary veins, reducing risk of complications

PreprocedurePreprocedure

mapping with CT diminishes fluoroscopic timemapping with CT diminishes fluoroscopic time

CT can also be used to evaluate for pulmonary vein CT can also be used to evaluate for pulmonary vein stenosisstenosis

after after the procedurethe procedure

MRI can be used similarly in patients who are able to receive MRI can be used similarly in patients who are able to receive MRIMRI


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ReferencesReferences

HaissaguerreHaissaguerre

M, M, JaisJais

P, Shah DC, et al. Spontaneous initiation of P, Shah DC, et al. Spontaneous initiation of atrialatrial

fibrillation by ectopic fibrillation by ectopic beats originating in the pulmonary veins. N beats originating in the pulmonary veins. N EnglEngl

J Med 1998;339:659J Med 1998;339:659--666.666.

JaisJais

P, P, HaissaguerreHaissaguerre

M, Shah DC, et al. A focal source of M, Shah DC, et al. A focal source of atrialatrial

fibrillation treated by discrete fibrillation treated by discrete radiofrequency ablation. Circulation 1997;95:572radiofrequency ablation. Circulation 1997;95:572--576576

SaadSaad

EB, EB, MarroucheMarrouche

NF, NF, SaadSaad

CP, et al. Pulmonary vein CP, et al. Pulmonary vein stenosisstenosis

after catheter ablation of after catheter ablation of atrialatrial

fibrillation: emergence of a new clinical syndrome. Ann Internfibrillation: emergence of a new clinical syndrome. Ann Intern

Med 2003; 138634Med 2003; 138634--638.638.

NahassNahass

GT. Acute GT. Acute radiodermatitisradiodermatitis

after radiofrequency catheter ablation. J Am after radiofrequency catheter ablation. J Am AcadAcad

DermatolDermatol

1997; 36:8811997; 36:881--884884

LacomisLacomis

J, J, WiggintonWigginton

W, et al. MultiW, et al. Multi--Detector Row CT of the Left Atrium and Pulmonary Veins Detector Row CT of the Left Atrium and Pulmonary Veins before Radiobefore Radio--frequency Catheter Ablation for frequency Catheter Ablation for AtrialAtrial

Fibrillation. Fibrillation. RadioGraphicsRadioGraphics

2003; 23:S352003; 23:S35--

S50S50


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Special thanks toSpecial thanks to……

MilliamMilliam

KataokaKataoka, MD, MD

Brian Callahan, MDBrian Callahan, MD

Justin Kung, MDJustin Kung, MD

Larry Larry BarbarasBarbaras

Gillian Lieberman, MDGillian Lieberman, MD

Maria Maria LevantakisLevantakis

Documents

CT of the Left Atrium and Pulmonary Veins before …eradiology.bidmc.harvard.edu/LearningLab/cardio/Chen.pdfCT of the Left Atrium and Pulmonary Veins before Radio- ... diameter of