Author + information
- Received April 2, 2018
- Revision received May 7, 2018
- Accepted May 14, 2018
- Published online September 17, 2018.
- Stephen Gaeta, MD, PhDa,
- Jacob N. Schroder, MDb,
- Mani A. Daneshmand, MD, PhDb,
- Kevin L. Thomas, MDa,c,
- Donald D. Hegland, MDa,
- Jonathan P. Piccini Sr., MD, MHSa,c,
- James P. Daubert, MDa,c,
- Jason I. Koontz, MD, PhDa,d and
- Albert Y. Sun, MDa,d,∗ ()
- aSection of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
- bDivision of Cardiothoracic Surgery, Department of Surgery, Duke University Medical Center, Durham, North Carolina
- cDuke Clinical Research Institute, Durham, North Carolina
- dDurham Veterans Affairs Hospital, Durham, North Carolina
- ↵∗Address for correspondence:
Dr. Albert Y. Sun, Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, Duke University Medical Center, DUMC Box 3154, P.O. Box 17969, Durham, North Carolina 27710.
A 54-year-old man with nonischemic cardiomyopathy and recurrent ventricular tachycardia (VT) refractory to quinidine, sotalol, mexiletine, and amiodarone; 4 prior ablation procedures; and bilateral sympathectomy was admitted in VT storm. Cardiac magnetic resonance imaging revealed asymmetric hypertrophy at the interventricular septum (IVS) and associated transmural delayed gadolinium enhancement. His clinical VT had cycle length of 430 ms with left-inferior axis and V4 precordial transition, consistent with that targeted during prior ablations (Figure 1A). Sinus rhythm bipolar mapping demonstrated low voltage on the left basal IVS at sites of prior ablation. With extracorporeal membrane oxygenation support, his previously hemodynamically intolerable VT was mapped endocardially from both ventricles using a multipolar mapping catheter. Earliest activation was only 15 ms pre-QRS complex, with diffuse breakout on the bilateral basal IVS, suggesting a likely intramural focus (Figure 1B). Wall thickness at this site was approximately 2 cm by intracardiac echocardiography (ICE). After coronary angiography revealed no suitable septal perforator branches for alcohol ablation, simultaneous unipolar radiofrequency ablation from opposing sides of the IVS was pursued. Catheter apposition was confirmed by electroanatomic mapping, fluoroscopy, and ICE (Figures 1C and 1D) and contact force was 5 to 15 g (only available for a single catheter). Ablation was first performed using 2 irrigated 3.5-mm open-irrigated (Thermocool ST SF and SF, Biosense Webster, Irvine, California) catheters at 40 W with normal saline irrigant, resulting in minimal slowing of his VT, unchanged impedances, and minimal changes identified by ICE. Simultaneous unipolar radiofrequency ablation was then repeated with the same configuration but half-normal saline irrigant, resulting in impedance drops of 15 to 30 Ω, microbubble formation and enhanced echogenicity on ICE (1,2), and VT termination. Following additional substrate ablation in this region, VT was uninducible by programmed stimulation with triple extrastimuli and did not recur during his hospitalization. Simultaneous unipolar radiofrequency ablation (3,4) and half-normal saline irrigation (5) are adjunctive techniques to enhance the depth of ablation lesions. In this case, a combination of these techniques successfully ablated a mid-myocardial focus deep within a hypertrophied ventricular septum.
Dr. Daneshmand has received speaking fees from Maquet as part of their Extracorporeal Life Support program. Dr. Hegland has received speaking fees from Medtronic, Boston Scientific, St. Jude Medical, Biosense, and Spectranetics as part of the Certified Compliance and Ethics Professional Fellowship Program. Dr. Piccini has received grants for clinical research from Abbott and Johnson & Johnson; and consulting fees from Johnson & Johnson. Dr. Daubert has received consulting, advisory board, and lecture fees from Zoll, VytronUS, Medtronic, Boston Scientific, St. Jude Medical, and Biotronik; and research grants from Medtronic, Boston Scientific, and St. Jude Medical. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Katia Zeppenfeld, MD, served as Guest Editor for this paper.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received April 2, 2018.
- Revision received May 7, 2018.
- Accepted May 14, 2018.
- Marrouche N.F.
- Iyer V.,
- Gambhir A.,
- Desai S.P.,
- Garan H.,
- Whang W.
- Yamada T.,
- Maddox W.R.,
- McElderry H.T.,
- Doppalapudi H.,
- Plumb V.J.,
- Kay G.N.