Recognising and managing complications of atrial ...

Recognizing & Managing
Complications of Atrial

Fibrillation Ablation

Sanjay Dixit, M.D.
Associate Professor, University of Pennsylvania School of Medicine
Director, Cardiac Electrophysiology Laboratory, Philadelphia V.A.M.C.

Disclosure-of-Relationship

Title of Presentation: Recognizing & Managing

Complications of AF Ablation

Speaker: Sanjay Dixit, M.D.

Honorarium / Grant Support: Medtronic, St Jude

Medical, Boston-Scientific, Biosense Webster.

Special Disclosure

• I have no special expertise on the subject of
“Complications During AF Ablation”

• All material used in this talk pertaining to
adverse outcomes is taken from the work of
other investigators……..

Evolution of AF Ablation:
University of Pennsylvania Experience

Paroxysmal / Persistent (73% / 27%) Paroxysmal / Persistent (60% / 40%)

LSPV Left
LIPV Shared

Right
Shared

4mm / 8mm / closed cool tip Open Irrigated

Anticoagulation During Ablation: Anticoagulation During Ablation:
ACT 250-300 / normal INR ACT 350-400 / INR >2.0
General Anesthesia
Conscious Sedation
Hospitalization: 1-3 days
Hospitalization: 3-5 days



1.5%

Serious Adverse Events During AF Ablation:
University of Pennsylvania Experience

p for trend = 0.01

2.6%

%
2.0%
1.7%

0%

<45 yrs 45-54 yrs 55-64 yrs >65 yrs

N=309 N=583 N=768 N=378

- Leong-Sit et al, Circulation A&E, 2010;3:452

Prevalence and Causes of Fatal
Complications during AF Ablation

- Cappato et al, JACC 2009;53 (19)

AF Ablation and Stroke

• Incidence of stroke in PV isolation: 0 - 4%

• Possible causes include ablation induced charring
(often adherent to “Lasso” catheter), sheath
thrombus and thrombogenic effects of AF

• Certain patient characteristics may predispose to
higher incidence of periprocedure thrombus
formation (Ren et al., JACC 2004)

Thrombus Formation on Lasso Catheter

Thrombus Formation at Edge of Long Sheaths

Thrombus Formation at Site of Lesion

Stroke & AF Ablation:
Management Strategies

• Aggressive anticoagulation:

- Early Heparin Dosing (pre trans-septal puncture)
- Maintaining activated clotting time >350 sec

• Sheath Management:

- Constant infusion of heparinized saline

• When Thrombus Identified:

- If localized on catheter – immediate withdrawal into RA
- If free thrombus, consider thrombolytic agents

Live monitoring during LA ablation is vital

AF Ablation and PV Stenosis

• Incidence of any PV stenosis: ~15% *

• Incidence of significant (>70%) PV stenosis: 1% - 3%

• Factors influencing development of PV stenosis

- Baseline PV Caliber
- Lesion size (method of lesion creation – 4-mm; 8-mm; cool tip)

- Lesion site and distribution

* Natale et al., Circulation 2003

Monitoring Catheter Location During
Lesion Creation

ICE Monitoring of PV Flow

- Ren et al, JCE 2002; 13:1076

PV Stenosis: Management Strategies

• Routine CT Scan or MRI at 3 months post PV Isolation
• In patients with significant PV stenosis (70%) consider

intervention – Angioplasty & Stenting (stent size ≥ 10mm)
• Late (~ 4 yrs) in-stent restenosis is not uncommon (~23%)

AF Ablation & Esophageal Injury

• True incidence of injury: Unknown

• Mechanism of injury: Thermal or Ischemic

• Prevalence of LA-Esophageal Fistula: 0.05%

• Factors influencing Esophageal Injury

- Lesion site and distribution
- Method of lesion creation – 4-mm; 8-mm; cool tip
- Patient characteristics (LA size; co-morbidities, etc.)

• Esophageal lesions observed in 17% cases 24-48 hrs post ablation; 9%
in high or mid-esophagus (had different appearance c/w lower
esophageal lesions

• 40% of patients manifesting esophageal lesions reported symptoms,
most common being chest discomfort and nausea

• No difference in observed esophageal temperatures during ablation
between groups manifesting and lacking esophageal lesions
39.3±0.8C versus 39.4±0.9C

• All patients manifesting esophageal lesions were maintained on oral

proton2p4umhpoiunrhsibiatofrtsearfterwards and show2edwreesoeluktsionaoftfelersions on

3-month gastroscopic evaluation.

Managing LA-Esophageal Fistula

• Seen in patients with small atria at the site of
confluent lesions in the posterior LA

• Upper GI symptoms / Signs of Systemic
Infection / Neurologic involvement 3 days to
3 weeks post ablation

• If diagnosis suspected, avoid esophageal
instrumentation; use MRI, CT Scan or TTE
instead; Intracardiac ultrasound imaging

• Immediate surgical intervention / repair is
the best option once diagnosis has been
established

• Temporary esophageal stenting may be an
option (Bunch, Day et al JCE 2006;17)

- Pappone et al, Circulation 2004

Avoiding Esophageal Injury During AF Ablation

• Titrating down power when creating lesions in posterior LA
• Demarcating esophageal course: CT, MRI, 3D tagging of temperature probe,

gastrograffin ingestion, intracardiac ultrasound
• Monitoring esophageal temperature changes during lesion creation

Phrenic Nerve Injury During AF Ablation

• Phrenic nerve injury may occur during ablation around right PVs (septal aspect);
more common with balloon based procedures

• Phrenic nerve paralysis typically recovers in the majority (can take up to a year)
• Usually pacing before / during energy delivery can help minimize injury

- Horton, Natale, et al, Heart Rhythm 2010;7

Pericardial Effusion During AF Ablation: Imaging with ICE

Other Complications During AF Ablation

• Aortic Root Injury / Fistula: During transseptal puncture avoid
anterior & high point of puncture – intracardiac ultrasound guidance
and /or demarcating aortic root

• Lasso Catheter Entrapment in MV Apparatus: Use orthogonal
fluoroscopy and intracardiac ultrasound during catheter
manipulation in LA, monitor electrograms, stay posterior – behind
the CS catheter in RAO projection

• Gastric Injury / Gastroparesis: Mechanism likely similar to
esophageal injury, autonomic modulation could also have a role

• Atrio-Bronchial Fistula / Bronchial Tree Injury: Very rare; can
potentially occur during superior PV isolation – especially with distal
energy delivery

• Organized Atrial Tachyarrhythmias

Serious Complications During AF
Ablation: Summary

• Relatively rare and can be mostly avoided

• If recognized early enough, the majority can be treated
without long-term sequelae

• Tools that can better define anatomy and / or localize
catheters (intracardiac ultrasound, 3-D mapping, CT / MR
merge) may decrease incidence of complication



Potential Complications During AF Ablation

Percutaneous Access
Vessel Injury; Arterial Cannulation - Inadvertent; Pneumo/Hemothorax;

Pneumo/Hemomediastinum; Lung Collapse; Nerve Injuries

Trans-septal Puncture / Catheter Manipulation
Cardiac Perforation; Coronary Sinus Perforation; Aortic Injury; Catheter Entrapment

Energy Delivery
Cardiac or CS Perforation; Valve, Phrenic, Esophageal, Bronchial Tree Injuries;

Gastroparesis; LA Disarticulation; Organized atrial tachyarrhythmias, etc.

Other complications: anesthesia, intubation, anaphylactic reactions, etc.

Recognizing Potential Life Threatening Complications
During AF Ablation

Symptoms

New Onset Chest Pain or Shortness of Breath

Signs
Diaphoresis, Hypotension with Tachycardia, O2 Saturation

Confirmation By Imaging Techniques Available in the Lab

Fluoroscopy Echocardiography

Air-Tissue Interface in Pneumothorax; Transthoracic / Intracardiac

Cardiac Silhouette in LAO view Transeophageal

Pericardial Effusion; Thrombus Formation
Valve Injury Tissue Damage during RFA;

PV Flow Velocities;

Sheath thrombus

Excessive tissue swelling During Lesion
Creation With Cool Tip Catheter

Appearance of “Char” Following Ablation

Prevalence and Causes of Fatal Complications during AF
Ablation

- Cappato et al, JACC 2009;53 (19)

% patients/yr Complications

N=1,058 procedures

P=NS

Major = 2.0% of pts /yr - stroke/TIA, tamponade, PV stenosis >70%, acute

heart failure, death (2 pts, LA-esophageal fistula, allergic Rx)

Minor = 4.5% of pts/yr - pericardial effusion, air embolism, vascular (e.g.

hematoma, AV fistula, pseudoaneurysm) +3-4% incidence AT

Incidence of Life Threatening
Complications During AF Ablations

• Not well reported or categorized

• Dependent On:
- Operator Experience
- Laboratory Volume
- Patient Characteristics

ICE Monitoring of PV Flow

65 cm/sec
Symptoms / signs of PV
stenosis not observed if
peak flow ≤ 158 cm / sec
(gradient ≤ 10 mm Hg)

105 cm/sec

Dixit, et al., Heart Rhythm 2004

A. Right-sided PVs (LAO) B. Left-sided PVs (RAO)

Supero Supero Superior Supero Supero Superior
Septal Lateral Anterior Posterior
Septal Lateral Anterior Posterior
Infero Infero Infero Infero
Septal Lateral Anterior Posterior

Inferior Inferior

C. D. LS

RS M
M V
V

Dixit, et al., Heart Rhythm 2004

A. 100
90

80

V (cm/sec) 70

60

50 Pre Ablation "V"
Post Ablation "V"
40

30

20

10

0

</= 2 3 Segments 4 Segments

Segments

50 46  20 cm/sec

B. 45 42  23 cm/sec
*40
V (cm/sec) 35 33  22 cm/sec

30

25

20

15

10

5

0 3 Segments 4 Segments Dixit, et al., Heart Rhythm 2004
</= 2 Segments