First-in-Man Rapid, Ultra–high-resolution Mapping of the Outflow Tracts Using the Advisor™ HD Grid Catheter

DOI: 10.19102/icrm.2021.120107S

ROBERT D. ANDERSON, MBBS,¹ GEOFFREY LEE, MBChB, PhD,¹ TIMOTHY CAMPBELL, BSc,^2,3 JOSHUA HAWSON, MBBS,¹ STUART P. THOMAS, BMed, PhD,^2,3 and SAURABH KUMAR, BSc(Med)/MBBS, PhD^2,3

¹Department of Cardiology, Royal Melbourne Hospital, Faculty of Medicine, Dentistry, and Health Science, University of Melbourne, Melbourne, Victoria, Australia

²Department of Cardiology, Westmead Hospital, Westmead New South Wales, Australia

³Westmead Applied Research Centre, University of Sydney, New South Wales, Australia

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KEYWORDS. Catheter ablation, premature ventricular complex, right ventricular outflow tract, high-density grid mapping.

Dr. Anderson is supported by postgraduate scholarships cofunded by the National Health and Medical Research Council (NHMRC) and the National Heart Foundation (NHF) and Royal Australasian College of Physicians NHMRC Woodcock Scholarships. Dr. Kumar discloses receiving consultant honoraria from Biosense Webster, Abbott Medical, Cardiac Electrophysiology Association of Australia, Sanofi Aventis; research grants from Biotronik and Abbott Medical; and fellowship support from NSW Early to Mid-career Fellowship, National Health and Medical Research Council of Australia. The other author reports no conflicts of interest for the published content.
Address correspondence to: Saurabh Kumar, BSc(Med)/MBBS, PhD. Email: saurabh.kumar@health.nsw.gov.au.

A 65-year-old man without structural heart disease was referred for catheter ablation of highly symptomatic bigeminal, monomorphic premature ventricular complexes (PVCs) believed to be originating from the left ventricular outflow tract (LVOT) (Figure 1, panel A). High-density activation mapping was performed using the EnSite™ NavX™ mapping system. PVCs were 15 ms pre-QRS (Figure 1, panel A, left column) in the distal coronary sinus and proximal anterior interventricular vein as mapped using a decapolar mapping catheter (Inquiry™). A novel paddle-shaped, high-resolution multipolar catheter (Advisor™ HD Grid), maneuvered to the coronary cusps via a retrograde aortic approach, demonstrated earliest activation in the aortic cusps at the right coronary cusp, 19 ms pre-QRS (Figure 1, panel A, middle column and panel D). The septal/free wall of the RVOT demonstrated activation 32 ms pre-QRS (Figure 1, panel A, right column; panel B; and panel E). Ablation was performed to the earliest RVOT activation site with immediate cessation of ectopy and consolidative lesions applied (Figure 1, panels C and F). Further consolidative lesions were also applied in the right coronary cusp at its earliest site. No immediate complications were recorded and the patient showed no recurrence at six weeks of follow-up. Activation mapping included 350 mapping points collected within 218 seconds of mapping time.

The novel Advisor™ HD Grid catheter is a high-density, 7-French mapping catheter with a paddle configuration with 18 1-mm-wide electrodes arranged in a 4 × 4 configuration with a 3-mm edge-to-edge separation (Figure 1, panel G). To our knowledge, this is the first description of its successful use for rapid, ultra–high-resolution activation mapping in the outflow tracts, allowing for differentiation of site of origin and successful ablation eventually in the septal/free wall RVOT despite ECG morphology suggestive of an LVOT origin. The catheter was safe, easily maneuverable in the cusps, and facilitated high-density electroanatomic definition of the cusps.