Quantifying Electropathology in Paediatric Patients with Congenital Heart Disease:
an intra-operative epicardial mapping study

Patients with congenital heart disease (CHD) are prone to development of
cardiac tachyarrhythmias. Important factors associated with this increased risk
include scar tissue and suture lines from prior cardiac surgery and
longstanding volume or pressure overload, leading to development of
electropathology. Structural remodeling of myocardial tissue underlies
development of complex electrical conduction disorders (i.e.:
electropathology), which in turn predispose to development of atrial and
ventricular tachyarrhythmias.
The majority of patients with hemodynamically significant CHD undergo surgical
correction or palliation at young age. Despite the relatively short duration of
volume/pressure overload, these patients still develop atrial tachyarrhythmias
during long-term follow up. The role of early and short standing
volume/pressure overload during the first weeks, months or years of life on
development of electropathology is unknown.

To quantify the role of different abnormal loading conditions on atrial and
ventricular electropathology in paediatric patients with CHD.

The FANTASIA study is a prospective observational study, which includes the
following study procedures: 1) intraoperative atrial and ventricular epicardial
mapping during sinus rhythm, 2) storage of postoperative continuous rhythm
recordings that are carried out according to standard care.

For participants of this study there are no direct benefits. Neither the
patient, nor the investigators are in any way compensated for their
participation with regards to this study. The risks associated with
participation are known to be negligible, since epicardial mapping using the
non-investigational product (see Medical Device Dossier) in over 500 patients
in previous METC-approved studies (MEC 2010-054, MEC 2014-393) did not cause
any complications. Since May 2020, epicardial mapping according to the FANTASIA
protocol has been routinely implemented in paediatric patients in the Erasmus
MC. First experience has demonstrated the safety of the mapping procedure in
paediatric patients, as no complication occurred during the mapping
procedure.[in press ICVTS] Epicardial mapping will only be performed during the
patient's own natural rhythm. The burden of participation in the FANTASIA study
is minimal. The duration of the surgical procedure is minimally prolonged by
the epicardial mapping procedure with an estimate of 10 minutes. With regard to
the use of postoperative continuous rhythm recordings in the FANTASIA study,
the only difference with standard care is that the rhythm recordings are
stored. Hence, this will have no effect whatsoever on the usual postoperative
course and treatment.
Group-relatedness exists because the study cannot be performed in adult
patients with CHD, since the role of early and short standing volume/pressure
overload cannot be studied in these adult patients due to the presence of aging
and longstanding volume/pressure overload as major confounding factors.