Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://cr.elmerpub.com

Short Communication

Volume 16, Number 2, April 2025, pages 161-168

Long-Term Outcomes and Predictors of Recurrence in Atrial Arrhythmia Ablations Post-Fontan Procedure: A Retrospective Analysis

Figure 1. Electroanatomic map for a 26-year-old female with history of hypoplastic left heart syndrome with a lateral tunnel Fontan who underwent electrophysiology study and ablation of atrial flutter. Anterior/posterior (left) and left anterior oblique (right) projections show the lateral tunnel Fontan and the pulmonary venous atrium, which was accessed with trans-baffle puncture and a Vizigo sheath (Carto). Activation map showed counterclockwise cavotricuspid isthmus dependent atrial flutter, which was successfully ablated with ablation (red and pink dots) on both the pulmonary venous atrial and Fontan portion of the cavotricuspid isthmus.

Figure 2. A 30-year-old male with tricuspid and pulmonary atresia status post bidirectional Glenn with anastomosis between the right-sided SVC and right pulmonary artery, classic right atrial appendage-pulmonary artery Fontan procedure, and history of bilateral cryo maze with conversion to extracardiac Fontan, and atrial reduction with septectomy presented for ablation of atypical atrial flutter. Electroanatomical 3D bipolar voltage and activation map created during atrial pacing from the epicardial pacemaker system is shown here. Activation map showed typical flutters with double loop mitral/septal scar re-entry and LA roof/LA appendage reentry that were ablated (red and pink dots). Trans-Fontan baffle puncture and balloon angioplasty of the Fontan baffle was performed for this procedure. LA: left atrial; SVC: superior vena cava.

**Table 1.** Patient Demographic and Clinical Correlates in Patients With and Without Arrhythmia Recurrence
	Overall (n = 25)	Recurrence (n = 12)	No recurrence (n = 13)	P-value
^aCongenital heart diseases were not in isolation and those such as TGA were associated with other lesions. BMI: body mass index; BNP: brain natriuretic peptide; CCI: Charlson Comorbidity Index; DILV: double inlet left ventricle; DORV: double outlet right ventricle; D-TGA/L-TGA: dextro-transposition of the great arteries/levo-transposition of the great arteries; EF: ejection fraction; HF: heart failure; HLHS: hypoplastic left heart syndrome; PA-IVS: pulmonary atresia with intact ventricular septum; PPM/ICD: pacemaker/implantable cardioverter defibrillator; TA: tricuspid atresia; VSF: ventricular systolic function.
Age at Fontan (years)	6.1	5.6	6.6	0.525
Age at ablation (years)	31.5	33.3	29.9	0.253
Male, n (%)	14 (56)	9 (75)	5 (42)	0.111
BMI	26.3	27.8	25	0.18
Type of Fontan (initial)
Atriopulmonary, n (%)	12 (48)	10 (91)	2 (17)	0.0006
Lateral tunnel, n (%)	9 (36)	1 (9)	8 (67)	0.0094
Extra-cardiac, n (%)	2 (8)	0 (0)	2 (17)	0.378
Congenital heart disease^a
TA, n (%)	10 (40)	8 (67)	2 (17)	0.0154
D-TGA/L-TGA, n (%)	9 (35)	4 (33)	5 (42)	1
DORV, n (%)	3 (12)	0 (0)	3 (25)	0.22
DILV, n (%)	3 (12)	1 (8.3)	2 (17)	1
HLHS, n (%)	4 (16)	0 (0)	4 (33)	0.0957
PA-IVS, n (%)	4 (16)	3 (25)	1 (8.3)	0.3
Other, n (%)	3 (12)	1 (8.3)	2 (17)	1
Pre-ablation cardiac medications	4	4.5	3.8	0.269
Antiarrhythmic	1.7	1.8	1.6	0.444
Anti-coagulation	0.96	1.09	0.92	0.205
Post-ablation cardiac medications	3.91	4.6	3.58	0.061
Antiarrhythmic	1.41	1.8	1.2	0.0256
Anti-coagulation	0.92	1.1	0.92	0.468
Pre-BNP	1,054	1,703	242	0.028
Post-BNP	524	862	111.9	0.017
Normal VSF (EF > 50%), n (%)	11 (52)	6 (54)	5 (50)	0.687
Mildly reduced VSF (EF 40-50%), n (%)	5 (24)	3 (27)	2 (20)	1
Significantly reduced VSF (EF < 40%), n (%)	5 (24)	2 (18)	3 (30)	1
Comorbidities
Prior HF, n (%)	13 (52)	7 (58)	6 (46)	0.695
Prior thrombosis, n (%)	4 (16)	0 (0)	4 (31)	0.0957
Prior PPM/ICD, n (%)	6 (24)	4 (33)	2 (12)	0.378
Prior cardioversion, n (%)	11 (44)	7 (58)	5 (38)	0.434
CCI (mean)	1.27	1.09	1.38	0.59

Table 1. Patient Demographic and Clinical Correlates in Patients With and Without Arrhythmia Recurrence

Overall (n = 25)

Recurrence (n = 12)

No recurrence (n = 13)

P-value

^aCongenital heart diseases were not in isolation and those such as TGA were associated with other lesions. BMI: body mass index; BNP: brain natriuretic peptide; CCI: Charlson Comorbidity Index; DILV: double inlet left ventricle; DORV: double outlet right ventricle; D-TGA/L-TGA: dextro-transposition of the great arteries/levo-transposition of the great arteries; EF: ejection fraction; HF: heart failure; HLHS: hypoplastic left heart syndrome; PA-IVS: pulmonary atresia with intact ventricular septum; PPM/ICD: pacemaker/implantable cardioverter defibrillator; TA: tricuspid atresia; VSF: ventricular systolic function.

Age at Fontan (years)

6.1

5.6

6.6

0.525

Age at ablation (years)

31.5

33.3

29.9

0.253

Male, n (%)

14 (56)

9 (75)

5 (42)

0.111

BMI

26.3

27.8

0.18

Type of Fontan (initial)

Atriopulmonary, n (%)

12 (48)

10 (91)

2 (17)

0.0006

Lateral tunnel, n (%)

9 (36)

1 (9)

8 (67)

0.0094

Extra-cardiac, n (%)

2 (8)

0 (0)

2 (17)

0.378

Congenital heart disease^a

TA, n (%)

10 (40)

8 (67)

2 (17)

0.0154

D-TGA/L-TGA, n (%)

9 (35)

4 (33)

5 (42)

DORV, n (%)

3 (12)

0 (0)

3 (25)

0.22

DILV, n (%)

3 (12)

1 (8.3)

2 (17)

HLHS, n (%)

4 (16)

0 (0)

4 (33)

0.0957

PA-IVS, n (%)

4 (16)

3 (25)

1 (8.3)

0.3

Other, n (%)

3 (12)

1 (8.3)

2 (17)

Pre-ablation cardiac medications

4.5

3.8

0.269

Antiarrhythmic

1.7

1.8

1.6

0.444

Anti-coagulation

0.96

1.09

0.92

0.205

Post-ablation cardiac medications

3.91

4.6

3.58

0.061

Antiarrhythmic

1.41

1.8

1.2

0.0256

Anti-coagulation

0.92

1.1

0.92

0.468

Pre-BNP

1,054

1,703

242

0.028

Post-BNP

524

862

111.9

0.017

Normal VSF (EF > 50%), n (%)

11 (52)

6 (54)

5 (50)

0.687

Mildly reduced VSF (EF 40-50%), n (%)

5 (24)

3 (27)

2 (20)

Significantly reduced VSF (EF < 40%), n (%)

5 (24)

2 (18)

3 (30)

Comorbidities

Prior HF, n (%)

13 (52)

7 (58)

6 (46)

0.695

Prior thrombosis, n (%)

4 (16)

0 (0)

4 (31)

0.0957

Prior PPM/ICD, n (%)

6 (24)

4 (33)

2 (12)

0.378

Prior cardioversion, n (%)

11 (44)

7 (58)

5 (38)

0.434

CCI (mean)

1.27

1.09

1.38

0.59

**Table 2.** Procedural Correlates in Patients With and Without Arrhythmia Recurrence
	Overall (n = 23)	Recurrence	No recurrence	P-value
Not all values were available for all included patients; values shown are calculated from available data. IVC: inferior vena cava; RA: right atrium; SVC: superior vena cava.
Length of procedure (min)	204	217	194	0.601
Number of applications	28.1	48	14	0.045
Mean cycle length (s)	725	761	691	0.642
Multiples arrhythmia, n (%)	18 (82)	10 (83)	8 (73)
Initial arrhythmia
Typical RA flutter	7 (33)	4 (40)	3 (27)	0.7
Atypical RA flutter	15 (71)	8 (80)	7 (63)	0.6
Type of ablation catheter
Biosense Thermocool SmartTouch SF™^{, n (%)}	16 (73)	8 (73)	8 (73)	1
TactiCath Abott™^{, n (%)}	6 (23)	3 (23)	3 (23)	1
Type of mapping catheter
CARTO 3D^® System, n (%)	12 (55)	6 (55)	6 (55)	1
Abbott^®, n (%)	3 (14)	2 (18)	1 (9.1)	1
Other, n (%)	3 (14)	1 (9)	2 (18)	1
Location of arrhythmia
Lateral RA/RA scar	7 (28)	4 (40)	3 (27)	0.659
Cavotricuspid isthmus, n (%)	6 (24)	3 (30)	3 (27)	1
Peri-IVC, n (%)	2 (8.0)	2 (20)	0 (0)	0.214
Posterior RA, n (%)	3 (12)	1 (10)	2 (18)	1
Anterior-septal RA, n (%)	4 (16)	3 (30)	1 (9.1)	0.59
Inferior RA, n (%)	1 (8.0)	1 (10)	0 (0)	1
Between SVC and RA, n (%)	3 (12)	0 (0)	3 (27)	0.214
SVC/SVC scar, n (%)	1 (8.0)	0 (0)	1 (9.1)	1
Around the sinus node, n (%)	1 (8.0)	0 (0)	1 (9.1)	1
Left atrial appendage/mitral annulus, n (%)	1 (8.0)	1 (10)	0 (0)	1

Table 2. Procedural Correlates in Patients With and Without Arrhythmia Recurrence

Overall (n = 23)

Recurrence

No recurrence

P-value

Not all values were available for all included patients; values shown are calculated from available data. IVC: inferior vena cava; RA: right atrium; SVC: superior vena cava.

Length of procedure (min)

204

217

194

0.601

Number of applications

28.1

0.045

Mean cycle length (s)

725

761

691

0.642

Multiples arrhythmia, n (%)

18 (82)

10 (83)

8 (73)

Initial arrhythmia

Typical RA flutter

7 (33)

4 (40)

3 (27)

0.7

Atypical RA flutter

15 (71)

8 (80)

7 (63)

0.6

Type of ablation catheter

Biosense Thermocool SmartTouch SF™^{, n (%)}

16 (73)

8 (73)

TactiCath Abott™^{, n (%)}

6 (23)

3 (23)

Type of mapping catheter

CARTO 3D^® System, n (%)

12 (55)

6 (55)

Abbott^®, n (%)

3 (14)

2 (18)

1 (9.1)

Other, n (%)

3 (14)

1 (9)

2 (18)

Location of arrhythmia

Lateral RA/RA scar

7 (28)

4 (40)

3 (27)

0.659

Cavotricuspid isthmus, n (%)

6 (24)

3 (30)

3 (27)

Peri-IVC, n (%)

2 (8.0)

2 (20)

0 (0)

0.214

Posterior RA, n (%)

3 (12)

1 (10)

2 (18)

Anterior-septal RA, n (%)

4 (16)

3 (30)

1 (9.1)

0.59

Inferior RA, n (%)

1 (8.0)

1 (10)

0 (0)

Between SVC and RA, n (%)

3 (12)

0 (0)

3 (27)

0.214

SVC/SVC scar, n (%)

1 (8.0)

0 (0)

1 (9.1)

Around the sinus node, n (%)

1 (8.0)

0 (0)

1 (9.1)

Left atrial appendage/mitral annulus, n (%)

1 (8.0)

1 (10)

0 (0)

**Table 3.** Hospitalization Outcomes in Patients With and Without Arrhythmia Recurrence
Cumulative hospitalizations data	Overall (n = 22)	Recurrence (n = 11)	No recurrence (n = 11)	P-value
CV: cardiovascular.
CV hospitalization
Within 6 months, n (%)	6 (27)	3 (27)	3 (3)	1
By 1 year, n (%)	8 (36)	4 (36)	4 (36)	1
By 5 years, n (%)	13 (59)	9 (82)	4 (36)	0.03
Non-CV hospitalization
Within 6 months, n (%)	1 (4.5)	0 (0)	1	0.308
By 1 year, n (%)	2 (9.1)	0 (0)	2	0.139
By 5 years, n (%)	7 (32)	3 (27)	4 (36)	0.645

Table 3. Hospitalization Outcomes in Patients With and Without Arrhythmia Recurrence

Cumulative hospitalizations data

Overall (n = 22)

Recurrence (n = 11)

No recurrence (n = 11)

P-value

CV: cardiovascular.

CV hospitalization

Within 6 months, n (%)

6 (27)

3 (27)

3 (3)

By 1 year, n (%)

8 (36)

4 (36)

By 5 years, n (%)

13 (59)

9 (82)

4 (36)

0.03

Non-CV hospitalization

Within 6 months, n (%)

1 (4.5)

0 (0)

0.308

By 1 year, n (%)

2 (9.1)

0 (0)

0.139

By 5 years, n (%)

7 (32)

3 (27)

4 (36)

0.645