In vivo left-ventricular contact force analysis: comparison of antegrade transseptal with retrograde transaortic mapping strategies and correlation of impedance and electrical amplitude with contact force.
OBJECTIVE
Clinical outcomes following radiofrequency ablation of ventricular tachycardias (VTs) depend on catheter tip-to-tissue contact force (CF). Left-ventricular (LV) mapping is performed via antegrade-transseptal or retrograde-transaortic approaches, and the applied CF may depend on the approach used. This study evaluated (i) the impact of antegrade-transseptal vs. retrograde-transaortic LV-mapping approaches on CF and catheter stability and (ii) the clinical value of the commonly used surrogate markers of catheter-myocardial contact-impedance, unipolar, and bipolar electrogram amplitudes.


RESULTS
An antegrade-transseptal and a retrograde-transaortic LV-mapping approach was performed in 10 patients undergoing VT ablation by using CF-sensing catheters. Operators were blinded to CF data and data were analysed according to 11 predefined LV segments. Three thousand three hundred and twenty-four mapping points (1577 antegrade, 1747 retrograde) were analysed, including 80 (2.4%) points with maximum CF > 100 g. Median antegrade and retrograde CF were 16.0 g (q1-q3; 8.4-26.2) and 15.3 g (9.8-23.4), respectively. Contact force was significantly higher antegradely in mid-anteroseptum, mid-lateral, and apical segments, and significantly higher retrogradely in basal-anteroseptum, basal-inferoseptum, basal-inferior, and basal-lateral segments. Contact force did correlate with impedance, unipolar, and bipolar electrogram amplitudes; however, there were large overlaps.


CONCLUSIONS
Antegrade vs. retrograde LV-mapping approaches result in different CF. A combined approach to the LV mapping may improve the overall LV mapping, potentially resulting in better clinical outcomes for the left VT catheter ablation. The previous surrogate markers used to assess CF do correlate with in vivo CF; however, due to a larger overlap, their clinical value is limited.
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany tilz6@hotmail.com.
Roland Richard
RR
Tilz
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Hisaki
H
Makimoto
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Tina
T
Lin
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Andreas
A
Rillig
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Andreas
A
Metzner
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Shibu
S
Mathew
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Sebastian
S
Deiss
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Erik
E
Wissner
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Peter
P
Rausch
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Masashi
M
Kamioka
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Christian
C
Heeger
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Karl-Heinz
KH
Kuck
Department of Cardiology, Asklepios Klinik St Georg, Lohmuehlenstr 5, 20099 Hamburg, Germany.
Feifan
F
Ouyang
D001011:Aorta; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D017097:Electric Impedance; D004574:Electromagnetic Fields; D005260:Female; D006346:Heart Septum / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*
Catheter ablation; Contact force; Ventricular tachycardia