Author + information
- Received December 9, 2015
- Revision received December 28, 2015
- Accepted January 7, 2016
- Published online August 1, 2016.
- Philippe Maury, MDa,∗ (, )
- Alexandre Duparc, MDa,
- Stefano Capellino, BEb,
- Pierre Mondoly, MDa and
- Anne Rollin, MDa
- aDepartment of Cardiology, University Hospital Rangueil Toulouse, Toulouse, France
- bBoston Scientific, Voisin Le Bretonneux, France
- ↵∗Reprint requests and correspondence:
Dr. Philippe Maury, Cardiology, University Hospital Rangueil, 1 avenue Jean Poulhes, 31059 Toulouse Cedex 09, France.
A 84-year-old woman with a remote anterior myocardial infarction and a left ventricular ejection fraction of 20% was referred for well-tolerated chronic monomorphic ventricular tachycardia (VT). VT recurred during hospitalization despite beta-blockers and oral loading with amiodarone, and it then became unremitting. VT displayed a left bundle branch block pattern and left superior axis, with a Q-wave in the precordial leads (cycle length, 460 ms).
High-density activation mapping (Rhythmia, Boston Scientific, Marlborough, Massachusetts) (1,2) revealed a simultaneous exit at the right and left ventricular lower aspects of the septum near the apex, at the border of the left ventricular anterior scar, with subsequent eccentric right and left ventricular activation (Figure 1, Online Video 1). Mapping of the left ventricle was performed in 32 min (28,669 activation points) and in 10 min for the right ventricle (5,947 points). Left ventricular endocardial activation time was 300 ms (65% VT cycle length) and 95 ms for the right ventricle (21%).
Intracardiac electrograms at both exit sites showed pre-systolic large potentials separated from the surface QRS complex by 60 to 90 ms. Entrainment at both exit points displayed post-pacing intervals equal to the VT cycle length, but concealed entrainment was only observed on the left side, suggestive of entrainment at the exit zone of an intraseptal circuit on the left side and at the outer loop on the right side.
Unipolar conventional radiofrequency application was ineffective at both sites, whereas use of 30-W bipolar RF application (3) between the distal tips of 2 irrigated standard RF catheters placed at both exit sites and connected to a dedicated switch box (Stockert, Freiberg, Germany) led to a rapid decrease in VT rate that terminated in 17 s. The patient was discharged on beta-blockers and amiodarone (previous atrial fibrillation) and did not report any recurrence over a follow-up of 6 months.
This case highlights the advantages of very high density activation mapping demonstrating the complete intraseptal location of the circuit. This case also illustrates the role of bipolar RF ablation in such resistant cases with intramural substrate.
For a supplemental video, please see the online version of this article.
Dr. Duparc is a consultant for Boston Scientific. Dr. Capellino is an employee of Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received December 9, 2015.
- Revision received December 28, 2015.
- Accepted January 7, 2016.
- American College of Cardiology Foundation