Bipolar ablation is an interesting option to treat some refractory VT cases. 2 case reports of LV free wall arrhythmias, bibliography and settings are presented
18. Case 2 : B J (71 yo)
Non ischemic cardiomyopathy EF 25% CRT ICD
4 fast VTs were previously ablated (3 septal and 1 peri mitral sites) :
50 W unipolar ablation
Redo slow VT cl 440 ms
Carto Users meeting
27. Bipolar vs unipolar ablation :
NAGASHIMA NAGASHIMA
KORUTH
2012
GIZURARSON
2014
NGUYEN
2016
Tissue
Healthy swine
septum
Healthy swine free
wall
Healthy swine
tissue
Explanted pathological
human basal free wall
Healthy bovine myocardium
Wall thickness 16 mm 15 mm 17 mm Maximal thickness 15-20 mm
Irrigated tip vs
8mm
irrigated Irrig et 10 mm irrigated irrigated Multiple configurations
Power 30-50-70 W 25 – 30 w
30 -50 W
M= 41W
50W 50 -70 W
Duration 120 120 120 60 60
Width 8 mm 10 NR 14 NR
Depth 5 à 8 mm 10 NR 10 9-13
Transmurality 0 à 71 % 45% 82% 100% NR
Steam Pop 3-6-14% NR NR NR
Irrigated perpendicular 50 W
and 8mm 70W
Carto Users meeting
28. Bipolar vs unipolar ablation : Efficiency
and safety
Lesion size :
Width : no difference
Depth : bipolar more efficient
Transmurality : bipolar more efficient
Steam pop :
Bipolar : safer ?
Carto Users meeting
29. Bipolar ablation : settings
Catheters connexion :
1 NAV catheter, 1 non NAV catheter.
Plugged in a « bipolar box » connected to the RF generator
Carto settings :
Only one catheter and its signals visualized
The second one’s positoning is guided by X-rays
Signals on EP lab :
Non NAV catheter should directly be connected in the RF generator to display the signal,
then disconected and plugged in the « bipolar box » to do ablation
Carto Users meeting
30. Bipolar ablation : Ablation settings
Ablation catheter : irrigated tip vs 8mm ?
Deeper lesions with 8 mm but more steam pops…
Power : titration …
30 w , 35 W, 40w …
Adapted to the wall thickness (a maximum distance of 20 to 25 mm between the
catheters)
Duration :
At least 30 seconds
Long duration ?
Impedance drop and plateau ?
Carto Users meeting
32. Bipolar ablation : summary
Indications : Diagnosis and mechanisms must be confirmed +++
Failure of a previous well performed high power ablation
Deep circuits with very thick wall or septum
Failure of a RVOT-LVOT ablation?
Calcifications or abnormal substrate…
Settings:
2 irrigated tip catheters
Official connexion tool …
Power and duration titration according to the wall thickeness and/or distance between the
catheters
Carto Users meeting
33. Bibliography :
Nagashima, K., et al. (2011). "Lesion formation by ventricular septal ablation with irrigated
electrodes: comparison of bipolar and sequential unipolar ablation." Circ J 75(3): 565-570.
Nagashima, K., et al. (2012). "Epicardial ablation with irrigated electrodes: - effect of bipolar vs.
unipolar ablation on lesion formation." Circ J 76(2): 322-327.
Koruth, J. S., et al. (2012). "Bipolar irrigated radiofrequency ablation: a therapeutic option for
refractory intramural atrial and ventricular tachycardia circuits." Heart Rhythm 9(12): 1932-1941.
Gizurarson, S., et al. (2014). "Bipolar ablation for deep intra-myocardial circuits: human ex vivo
development and in vivo experience." Europace 16(11): 1684-1688
Nguyen, D. T., et al. (2016). "Clinical and biophysical evaluation of variable bipolar configurations
during radiofrequency ablation for treatment of ventricular arrhythmias." Heart Rhythm 13(11):
2161-2171
Carto Users meeting
