Combined analysis of unipolar and bipolar voltage mapping identifies recurrences after unmappable scar-related ventricular tachycardia ablation.
OBJECTIVE
Scars causing ventricular tachycardia can extend deep to and beyond bipolar low-voltage areas (LVAs) and they may be a reason for endocardial ablation failure. Analysis of endocardial unipolar voltage maps has been used to detect scar transmurality and epicardial scar. We hypothesized that endocardial unipolar LVA around the overlying bipolar LVA may predict endocardial ablation recurrence in patients with structural heart disease undergoing substrate modification.


RESULTS
Twenty consecutive patients with structural heart disease (11 ischaemic and 9 non-ischaemic cardiomyopathy) and undergoing substrate modification due to unmappable ventricular tachycardia (VT) (18 males, 51 ± 11 age, LVEF: 36 ± 7%) were retrospectively reviewed. Bipolar LVA defined as <1.5 mV and unipolar LVA defined as <8.3 mV, respectively, on electro-anatomic mapping system. Peripheral unipolar LVA (pUni-LVA) surrounding bipolar LVA was measured and compared patients with and without VT recurrence at 6-month follow-up period. : Mean unipolar voltage and mean bipolar voltage was 6.26 ± 4.99 and 1.90 ± 2.30 mV, respectively. Bipolar voltage and unipolar voltage in corresponding points were correlated (r = 0.652, P = 0.0001). In all patients, unipolar LVAs were larger than the bipolar LVAs. Bipolar LVA (91.1 ± 93.5 vs. 87.5 ± 47.5 cm(2), P = 0.91) and unipolar LVA (148.1 ± 96.3 vs. 104.7 ± 44.2 cm(2), P = 0.21) were similar in patients with and without VT recurrence, respectively. Peripheral unipolar LVA was significantly larger in patients with VT recurrence than without (57.0 ± 40.4 vs. 17.2 ± 12.9 cm(2), P = 0.01).


CONCLUSIONS
In patients with structural heart disease and unmappable VT, pUni-LVA surrounding bipolar scar predicts recurrence of VT ablation. The results of this pilot study highlight the importance of intramural/epicardial substrate on endocardial VT ablation outcome.
Department of Cardiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul Tıp Fakültesi-Fatih, Fatih, Istanbul 34104, Turkey Cardiology Clinic, Bursa State Hospital, Kliniği Osmangazi, Alaaddin Mh., Bursa 16040, Turkey yalinkivanc@gmail.com.
Kivanc
K
Yalin
Department of Cardiology, School of Medicine, Koc University, Davutpaşa Cd. No:4 Topkapı, İstanbul, Turkey.
Ebru
E
Golcuk
Department of Cardiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul Tıp Fakültesi-Fatih, Fatih, Istanbul 34104, Turkey.
Ahmet Kaya
AK
Bilge
Department of Cardiology, Kocaeli Derice Research and Training Hospital, İbnisina Mh. Lojman Sk. Derince, Kocaeli, Turkey.
Tolga
T
Aksu
Mavi Ucak Software, Kandilli, Usküdar, Istanbul, Turkey.
Hakan
H
Buyukbayrak
Cardiology Clinic, Bursa State Hospital, Kliniği Osmangazi, Alaaddin Mh., Bursa 16040, Turkey.
Selma Kenar
SK
Tiryakioglu
Department of Cardiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul Tıp Fakültesi-Fatih, Fatih, Istanbul 34104, Turkey.
Samim
S
Emet
Department of Cardiology, Istanbul Faculty of Medicine, Istanbul University, Istanbul Tıp Fakültesi-Fatih, Fatih, Istanbul 34104, Turkey.
Kamil
K
Adalet
D000328:Adult; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D002921:Cicatrix / Q000503:physiopathology*; D004699:Endocardium / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012372:ROC Curve; D012008:Recurrence; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000601:surgery*
Ablation; Recurrence; Unipolar mapping; Ventricular tachycardia