Author + information
- Received September 10, 2018
- Revision received September 25, 2018
- Accepted October 4, 2018
- Published online February 18, 2019.
- Dominik Linz, MD, PhD,
- Bradley Pitman, BSc,
- Kadhim Kadhim, MBChB,
- Catherine O’Shea, MBBS,
- Rajiv Mahajan, MD, PhD,
- Prashanthan Sanders, MBBS, PhD and
- Dennis H. Lau, MBBS, PhD∗ ()
- Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia
- ↵∗Address for correspondence:
Dr. Dennis H. Lau, Centre for Heart Rhythm Disorders, Department of Cardiology, Royal Adelaide Hospital, 1 Port Road, Adelaide 5000, Australia.
A 61-year-old man underwent a single-chamber permanent pacemaker implantation followed by successful atrioventricular (AV) node ablation 3 weeks later for rate control of atrial fibrillation (1). Six weeks later, he presented with exertional dyspnea and orthopnea. Echocardiography showed a reduction in left ventricular ejection fraction from 58% to 25%, suggestive of pacing-induced cardiomyopathy. Despite optimal heart failure therapy for 4 months, his left ventricular ejection fraction remained at 27%. He was brought in for His-bundle pacing or upgrade to cardiac resynchronization therapy (2).
Right ventricular pacing from the septal outflow tract resulted in a broad QRS interval (174 ms) (Figure 1A). Inhibition of pacing revealed an intrinsic rhythm of complete AV block and a slow escape rhythm at 40 beats/min (QRS interval: 96 ms) (Figure 1B). Unipolar mapping of the His bundle was performed with a SelectSecure lead (models 3830 and C315, respectively; Medtronic, Minneapolis, Minnesota) (Figure 1D) via a delivery sheath at the AV septal region. During escape rhythm, mapping failed to identify any local His-bundle potential. As the patient was hypotensive during the slow escape rhythm, further mapping was then performed with pacing from the existing pacemaker lead. A retrograde His-bundle potential could be mapped at the distal His-bundle region (VH interval: 68 ms) (Figure 1E) with nonselective capture (QRS interval: 102 ms) (Figure 1C). The SelectSecure lead was deployed successfully (sensing 3.5 mV; pacing threshold: 1.5 V at 1 ms) and connected to the atrial port of a dual-chamber pacemaker (Ensura EN1DR01, Medtronic) with the existing right ventricular lead in the ventricular port (dual-chamber, rate modulated pacing programming, AV delay of 30 ms and fixed output of 3.5 V at 1 ms for the SelectSecure lead).
The patient experienced significant improvement in heart failure symptoms within weeks accompanied by improved left ventricular ejection fraction to 44% after 3 months’ post–His-bundle pacing. To our knowledge, this is the first report of His-bundle pacing after AV node ablation guided by retrograde His-bundle potential from right ventricular pacing.
Dr. Linz has served on the advisory board of LivaNova and Medtronic; has received lecture and/or consulting fees from LivaNova, Medtronic, and ResMed; and has received research funding from Sanofi, ResMed, and Medtronic. Dr. Mahajan has served on the advisory board of Boston Scientific; has received consulting honoraria from Medtronic, Abbott, Pfizer, and Bayer; and has received research funding from Abbott and Medtronic; and the University of Adelaide has received research funding on his behalf from Medtronic and St. Jude Medical. Dr. Sanders has served on the advisory boards of Biosense Webster, Medtronic, Abbott, St. Jude Medical, Boston Scientific, and CathRx; has received a Practitioner Fellowship from the National Health and Medical Research Council of Australia and the National Heart Foundation of Australia and the Neil Hamilton Fairley Early Career Fellowship from the National Health and Medical Research Council of Australia; and the University of Adelaide has received lecture and/or consulting fees on his behalf from Biosense Webster, Medtronic, Abbott, St. Jude Medical, and Boston Scientific; and research funding on his behalf from Medtronic, Abbott, St. Jude Medical, Boston Scientific, Biotronik, and LivaNova. Dr. Lau has received lecture and/or consulting fees awarded to the University of Adelaide on his behalf from St. Jude Medical, Bayer, Boehringer Ingelheim, and Pfizer. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
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 September 10, 2018.
- Revision received September 25, 2018.
- Accepted October 4, 2018.
- 2019 American College of Cardiology Foundation
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