Author + information
- Geoffrey R. Wong, MBBSa,b,
- Chrishan J. Nalliah, MBBSa,b,
- Geoffrey Lee, MBChB, PhDa,
- Aleksandr Voskoboinik, MBBSc,d,
- Sandeep Prabhu, MBBSc,d,
- Ramanathan Parameswaran, MBBSa,b,
- Hariharan Sugumar, MBBSc,d,
- Robert D. Anderson, MBBSa,b,
- Alex McLellan, MBBS, PhDa,c,
- Liang-Han Ling, MBBS, PhDc,d,
- Joseph B. Morton, MBBS, PhDa,
- Prashanthan Sanders, MBBS, PhDe,
- Peter M. Kistler, MBBS, PhDc,d and
- Jonathan M. Kalman, MBBS, PhDa,b,∗ ()
- aDepartment of Cardiology, Royal Melbourne Hospital, Melbourne, Australia
- bDepartment of Medicine, University of Melbourne, Melbourne, Australia
- cBaker IDI Heart and Diabetes Institute, Melbourne, Australia
- dHeart Centre, Alfred Hospital, Melbourne, Australia
- eCentre for Heart Rhythm Disorders, Royal Adelaide Hospital, Adelaide, Australia
- ↵∗Address for correspondence:
Dr. Jonathan Kalman, Department of Cardiology, Royal Melbourne Hospital, Grattan Street, Parkville, Victoria 3050, Melbourne, Australia.
Objectives This study sought to determine the impact of rate and direction on left atrial (LA) substrate.
Background The extent to which substrate mapped in sinus rhythm varies according to cycle length and direction of wave front propagation is unknown.
Methods A total of 73 consecutive patients with atrial fibrillation (AF) underwent electroanatomic LA mapping before pulmonary vein isolation using multipolar catheter during distal coronary sinus (CS) pacing at 600 ms and 300 ms. Additional maps were created during left superior pulmonary vein pacing at 300 ms. Bipolar voltage, conduction velocity (CV), and complex signals were determined.
Results Mean age was 61 ± 9 years, 67% were men, and 53% had persistent AF. Global mean voltage was lower with CS pacing at 300 ms compared with 600 ms (1.56 ± 0.47 mV vs. 1.74 ± 0.48 mV; p < 0.001). This was seen in all LA segments. Global CV was reduced (30.4 ± 13.0 cm/s vs. 38.6 ± 14.0 cm/s; p < 0.001) with greater complex signals at 300 ms (8.9% vs. 5.3%; p < 0.005). Compared with CS pacing, left superior pulmonary vein pacing demonstrated highly regional changes with decreased voltage (1.04 ± 0.43 mV vs. 1.47 ± 0.53 mV; p = 0.01) and CV (24.4 ± 13.0 cm/s vs. 39.9 ± 16.6 cm/s; p = 0.008), and greater complex signals posteriorly. Longer AF duration in paroxysmal AF (p = 0.02) and shorter duration in persistent AF (p = 0.015) and left ventricular ejection fraction (p = 0.016) were independent predictors of voltage change.
Conclusions In patients with AF, variation in cycle length and direction of wave front activation produce both generalized and regional changes in voltage, CV, and complex fractionation, resulting in significant changes in substrate maps. This study highlights the potential limitations of static low-voltage maps to identify the AF ablation target zone.
- atrial fibrillation
- atrial substrate
- conduction velocity
- cycle length
- direction-dependent conduction
- electroanatomic mapping
- left atrium
- low-voltage zone
Dr. Wong is supported by National Health and Medical Research Council/National Heart Foundation postgraduate scholarships. Dr. Kalman is supported by a National Health and Medical Research Council practitioner fellowship. Dr. McLellan is supported by a Heart Foundation postdoctoral fellowship. Dr. Sanders is supported by a practitioner fellowship from the National Health and Medical Research Council of Australia. Dr. Sanders has served on the advisory board for Boston Scientific, Abbott Vascular, Medtronic, and CathRx; has received research funding from Boston Scientific, Abbott Vascular, and Medtronic; and has served as the Knapman Chair for the National Heart Foundation of Australia. Dr. Kalman has served on the advisory board of Biosense Webster; and has received receiving research and fellowship support from Biosense Webster, Boston Scientific, St. Jude Medical, and Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Isabel Deisenhofer, MD, served as Guest Editor for this paper.
The 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 March 26, 2019.
- Revision received May 16, 2019.
- Accepted June 5, 2019.
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