Right Ventricular Diastolic Function in Chronic Adverse RV Loading And Congenital Heart Disease
Right Ventricular Diastolic Function in Chronic Adverse RV Loading And Congenital Heart Disease
The aim of the study is to assess the characteristics, incidence and predictors of
 load-independent right ventricle (RV) diastolic dysfunction in patients with congenital heart
 disease (CHD) and adverse RV loading conditions by acquiring pressure-volume loops and
 compare these results to a population of patients with exclusion of coronary artery disease
 and absence of any known disease affecting the RV.
One of the major problems in the expanding population of patients with congenital heart
 disease (CHD) is dysfunction of the right ventricular (RV) outflow tract (OT). Initial
 surgical repair for complex conditions or repeated surgery for free pulmonary regurgitation
 often includes the creation of an artificial RV to main pulmonary artery connection. Over
 time, these conduits are prone to develop valvar incompetence or obstruction. There is clear
 evidence that pulmonary stenosis and pulmonary regurgitation are associated with exercise
 intolerance, arrhythmias and an increased risk of sudden death. Timely pulmonary valve
 replacement can halt and may reverse such unfavourable outcomes. However, this means that
 patients have to undergo multiple open-heart surgeries in order to reduce the haemodynamic
 burden on the right ventricle. Decision making in these patients with RVOT dysfunction is
 based on the aim to perform pulmonary valve replacement as late as possible to minimise the
 total number of open-heart surgeries required in individual patients, but before functional
 impairment might be irreversible. Importantly, this point of 'no return' in right ventricular
 pressure and/or volume overload is still unknown and represents one of the most challenging
 problems in the field of CHD. Ideally, quality of life, survival and freedom from atrial and
 ventricular arrhythmia should be the endpoints for any study trying to optimise timing of
 pulmonary valve replacement. However, such studies would require long follow-up in large
 patient populations and will not help to improve management of right ventricular outflow
 tract (RVOT) dysfunction in the short-term. In order to design studies with surrogate
 functional endpoints, a sound understanding of physiological consequences of altering RV
 loading and its implications for bi-ventricular function or exercise capacity is pivotal.

 The investigators established a method of acquiring robust RV pressure-volume-loops at our
 institution. In the context of a research study, the investigators performed RV conductance
 catheter measurements in 22 patients with heart failure with preserved ejection fraction and
 in 11 patients with no evidence of any RV disease. Within the RaDICAL study the investigators
 aim further to compare these results to pressure-volume loops acquired in patients with
 congenital heart disease (CHD) and adverse RV loading conditions in order to evaluate
 characteristics, incidence and predictors of load-independent right ventricle (RV) diastolic
 dysfunction.
Inclusion Criteria:

 -  Patient with CHD involving the RV

 -  Chronic RV volume and/or pressure overload as defined by:

 -  more than mild pulmonary regurgitation and/or

 -  more than mild tricuspid regurgitation and/or

 -  a gradient across the RV outflow tract of ≥ 3 m/s on echocardiography and/or

 -  estimated RV systolic pressure > 65 mmHg

 -  Clinical indication for cardiac catheterization

 -  Age 12 to 80 years

 -  Informed consent

 Exclusion Criteria:

 -  Contraindication for magnetic resonance imaging or cardiopulmonary exercise testing

 -  Pregnancy

 -  RV systolic function on magnetic resonance imaging < 45%