Catheter Ablation of Accessory Pathways: Can We Do Better by
Using Dual Chamber Mapping ?
Authors: Hugh Calkins, MD
Institution: Division of Cardiology, Department of Medicine, Johns
Hopkins University School of Medicine, Baltimore, MD, USA
Disclosures: Dr Calkins is a consultant and/or has received speaker
honoraria from Medtronic, Biosense Webster, and Abbott Medical.
Funding: None
Word Count: 1237
Address for Correspondence:
Hugh Calkins MD
Sheikh Zayed Tower 7125R
Johns Hopkins Hospital
1800 Orleans Street
Baltimore MD 21287
Phone: 410 955 3339
Fax: 410-367-2148
E-mail: hcalkins@jhmi.edu
Radiofrequency catheter ablation of accessory pathways was first
introduced in the late 1980’s through the pioneering efforts of Mel
Scheinman, Fred Morady, Warren Jackman, and others (1). The procedure
was rapidly shown to be safe and effective. While initially performed as
a staged procedure with a diagnostic EP study performed weeks in advance
of ablation, the concept of “diagnosis and cure” during the same
procedure was shown to be feasible in 1991 and has adopted worldwide
(2). As evidence of the safety and effective of ablation of APs, a
single center clinical trial of 250 patients with an accessory pathway
in 1994 reported a success rate of 94 %, and a complication rate of 4
% (3). And, a large multicenter clinical trial in 1999 reported a
success rate of 93 % (4). It is notable that these excellent results
were achieved with point by point electrogram based mapping under
fluoroscopic guidance prior to the development of 3D mapping systems
such as Carto, Ensite, and the Arrhythmia mapping system. Over the past
10 – 20 years there has been a gradual adoption of 3D mapping systems
for all ablation procedure. As an experienced operator with excellent
results achieved with only fluoroscopic mapping, I initially did not see
the value in employing a 3D mapping system for these “simple” ablation
procedures. But with time my approach has changed and I now employ 3D
mapping systems with all ablation procedures. Consistent with my
experience, a recent large retrospective multicenter study revealed both
improved efficacy and a lower fluoroscopy exposure in patients who
underwent RF catheter ablation of an accessory pathway guided by 3D
mapping as compared with the standard fluoroscopic approach (5).
In this issue, Mori et al. present their study investigating the
relative utility of standard 3D single chamber mapping using the Ensite
or Carto mapping systems with 3D dual chamber mapping approach using the
Arrhythmia mapping system (6). This single center nonrandomized trial
enrolled 111 patients undergoing catheter ablation of an accessory
pathway. Fifty patients had a standard 3D single chamber map performed
and 61 patients had the Arrhythmia guided 3D dual chamber map performed
to determine the location of the accessory pathway. The end points of
the trial were ablation success, recurrence rates, number of RF lesions,
total RF ablation time, RF dose, fluoroscopy time, and fluoroscopy dose.
The results of the study revealed no difference in ablation success
(50/50 vs 61/61) or AP recurrence during follow-up (2/50 vs 1/50, p NS).
Each of the other parameters studied were shorter in the Arrhythmia dual
chamber arm as compared with the conventional single chamber arm: # RF
applications 1 vs 3, RF time 9.2 vs 96.6 sec, RF energy 248 vs 2867 J,
fluoro time 19.2 vs 26.5 min, fluoro dose 52.5 vs 119 mGy. The only
complication was cardiac tamponade due to RV perforation in one patient
in the dual chamber group.
The results of this study are impressive. The Arrhythmia mapping system
was shown to have several advantages as compared with the standard 3D
single chamber approach. Of particular note were the reduction in the
number of RF lesions needed for success (median of 1 vs 3) as well as
marked reductions in RF time and RF energy. The 7-minute reduction in
fluoroscopy time is also notable. Before all EPs go out an acquire the
Arrhythmia mapping system, or utilize it for AP ablation if they have
access to this mapping system, it is important to consider some of the
limitations of this study. The first limitation was that it was
retrospective in design. Secondly, operator bias cannot be excluded. And
third there was no mention of total procedure time and the cost of the
procedure. In my experience what matters most to patients is freedom
from complications, and acute and long-term procedure success. These
parameters did not differ. A third parameter patients and hospitals care
about is total procedure time. And as noted above, this information was
not provided and a fourth parameter that health systems and insurers
care about is procedure cost. And again, as noted above, this
information was not provided. I suspect patients care little about
whether 1 or 3 RF applications was needed for success nor about the
total RF energy delivered. Patients do care about fluoroscopy time and
radiation exposure. And for this parameter the Arrhythmia dual chamber
mapping approach was superior. But does a 6-minute difference in
fluoroscopy time really matter when it comes to radiation associated
risk to patient?
At the end of the day we should congratulate Dr Mori and his colleagues
for conducting an important clinical trial comparing standard single
chamber 3D mapping and 3D dual chamber mapping with the Arrhythmia
system. These investigators have taught us the value of 3D dual chamber
mapping. It will be fascinating to see the ripple effect of this study.
Will EPs all over the world start using this system when mapping and
ablating a patient with an AP or not? For me the answer is not yet. I
have performed thousands of procedures with my current 3D mapping system
including hundreds of patients with an AP. My outcomes have been
excellent and I see no need to utilize a different system. But if I run
across a patient where I am unable to be successful with a standard
approach, I will be very tempted to utilize the Arrhythmia system if a
second ablation procedure is needed.
References:
- Scheinman MM. The History of the Wolff-Parkinson-White Syndrome RMMJ
2012; 3 (3); e0019
- Calkins H, Sousa J, El‑Atassi R, Rosenheck S, de Buitleir M, Kou W,
Kadish A, Langberg J, Morady F. Diagnosis and cure of the
Wolff‑Parkinson‑White syndrome or paroxysmal supraventricular
tachycardias during a single electrophysiologic test. N Engl J Med
1991; 324:1612‑8.
- Calkins H, Langberg J, Sousa J, El‑Atassi R, Leon A, Kou W,
Kalbfleisch S. Radiofrequency catheter ablation of accessory
atrioventricular connections in 250 patients: abbreviated therapeutic
approach to the Wolff‑Parkinson‑White syndrome. Circulation 1992;
85:1337‑1346.
- Calkins H, Yong P, Miller JM, Olshansky B, Carlson M, Saul JP, Huang
SK, LB Liem, Klein LS, Moser SA, Bloch DA, Gillette P, Prystowsky E
and the Atakr Investigators; Catheter Ablation of Accessory Pathways,
Atrioventricular nodal Reentrant Tachycardia, and the Atrioventricular
Junction: Final Results of a Prospective Clinical Trial. Circulation
1999; 99: 262-270.
- Ceresnak SR, Dubin AM, Kin JJ, Valdes SO, Tishberger SB, Shetty I,
Zimmerman F, Tanel RE, Epstein MR, Motonaga KS, Capone CA, Nappo L,
Gates GJ, Pass RH Success Rayes in Pediatric WPW Ablation Are Improved
with 3-Dimensional Mapping Systems Compared with Fluoroscopy Alone: A
Multicenter Study J Cardioasc Electrophysiol 2015; 26: 412-416
- Mori H, Kawano D, Sunitomo N, Muraji S, Nabeshima T, Tsutsui K, Ikeda
Y, Iwanga S, Nakano S, Muramatsu T, Kobayahi T, Kato R, Matsumoto K.
Ultra-high Density Atrio-Ventriculat Dual Chamber Mapping as a next
Generation Tool for Ablation of Accessory Pathways. JCVEP 2021 In
Press