Pediatr Cardiol. 2017 Aug;38(6):1097-1105. doi: 10.1007/s00246-017-1656-z. Epub 2017 Jun 16.
Tetralogy of Fallot is the most common form of cyanotic congenital heart disease.
As a result of the surgical strategies employed at the time of initial repair,
chronic pulmonary regurgitation (PR) is prevalent in this population. Despite
sustained research efforts, patient selection and timing of pulmonary valve
replacement (PVR) to address PR in young asymptomatic patients with repaired
tetralogy of Fallot (rToF) remain a fundamental but as yet unanswered question in
the field of congenital heart disease. The ability of the heart to compensate for
the chronic volume overload imposed by PR is critical in the evaluation of the
risks and benefits of PVR. The difficulty in clarifying the functional impact of
PR on the cardiovascular capacity may be in part responsible for the uncertainty
surrounding the timing of PVR. Cardiopulmonary exercise testing (CPET) may be
used to assess abnormal cardiovascular response to increased physiologic demands.
However, its use as a tool for risk stratification in asymptomatic adolescents
and young adults with rToF is still ill-defined. In this paper, we review the
role of CPET as a potentially valuable adjunct to current risk stratification
strategies with a focus on asymptomatic rToF adolescents and young adults being
considered for PVR. The role of maximal and submaximal exercise measurements to
identify young patients with a decreased or borderline low peak VO2 resulting
from impaired ventricular function is explored. Current knowledge gaps and
research perspectives are highlighted.