Summary
Adult patients with congenital heart disease (ACHD) represent a growing population due to progress in management. Surgical procedures generally fall short of restoring entirely normal anatomical and functional relations. Further procedures can be needed and lifelong follow-up is required. The right ventricle (RV) plays an important role in congenital heart disease and cardiac magnetic resonance (CMR) imaging has become the imaging method of choice for its assessment. CMR can provide relatively accurate measurements of RV volume and function, and arterial flow, with additional anatomical information provided by three-dimensional contrast angiography and late gadolinium imaging of fibrosis. Here we focus our review on three categories of ACHD in which evaluation of the RV is important: repaired tetralogy of Fallot, the systemic RV and Ebstein anomaly. We demonstrate how CMR contributes to decision-making regarding the types and timings of interventions. A dedicated CMR service should be regarded as a necessary facility of a centre specializing in the care of ACHD patients.
Résumé
Les adultes atteints de cardiopathies congénitales représentent une population de patients qui augmente grâce aux progrès dans leur prise en charge. Les interventions chirurgicales ne peuvent aboutir à un cœur complètement normal dans son anatomie et sa fonction. D’autres interventions peuvent s’avérer nécessaires et un suivi à vie est requis. Le ventricule droit (VD) a un rôle important dans les cardiopathies congénitales et l’imagerie par résonance magnétique (IRM) est la méthode de choix pour son évaluation. Elle permet d’estimer de façon relativement rigoureuse le volume et la fonction du VD, ainsi que la mesure des flux artériels. Elle permet également d’apporter des informations complémentaires anatomiques par l’angiographie 3D et de caractérisation tissulaire par la mise en évidence de fibrose. Nous concentrons cette revue sur trois catégories de pathologie pour lesquelles l’évaluation du VD est essentielle : la tetralogy de Fallot réparée, le VD en position systémique et l’anomalie d’Ebstein. Nous montrons comment l’IRM intervient dans la prise en charge décisionnelle pour le type et le timing d’intervention. Un service d’imagerie dédié est souhaitable dans les centres spécialisés dans la prise en charge des patients atteints de cardiopathie congénitale.
Background
Congenital heart disease occurs in about six to eight of 1000 live births . Progresses in paediatric cardiology and cardiac surgery have revolutionized patients management, allowing most affected children to survive into adulthood. However, surgical procedures generally fall short of restoring entirely normal anatomical and functional relations. Most patients need lifelong follow-up and many require further intervention. The need to understand and manage appropriately the growing population with adult congenital heart disease (ACHD) or grown-up congenital heart disease has led to an expanding cardiological subspecialty in which imaging plays a key role.
In a number of conditions, the right ventricle (RV) is prone to dilatation and arrhythmia and it has received increasing attention in recent decades . Two-dimensional echocardiography is the first-line cardiovascular imaging modality in ACHD, but RV volumetric and functional assessments remain challenging due to the asymmetric shape, trabeculated structure and the particular combination of long- and short-axis functions of the RV . Cardiovascular magnetic resonance (CMR) imaging allows a segmental analysis and has gained importance in the measurement and visualization of RV volume and function . RV function and volume evaluation is of importance in most repaired or unrepaired ACHDs, such as atrial septal defect, pulmonary atresia with intact ventricular septum, double outlet RV, tetralogy of Fallot (TOF), systemic RV and Ebstein anomaly. Repaired double outlet RV with subaortic ventricular septal defect and subpulmonary stenosis can be integrated into the section covering analysis of TOF. Finally, CMR contributes to decision-making regarding the types and timings of interventions.
Here we will focus on three categories of ACHD in which RV evaluation by CMR is crucial in clinical decision-making: repaired TOF (rTOF), the systemic RV and Ebstein anomaly.
Repaired tetralogy of Fallot
In 1945, Blalock and Taussig described the palliation of TOF by means of a systemic-to-pulmonary arterial shunt. Lillehi et al. reported the first open-heart anatomical repair of TOF in 1954 ( Fig.1-1 and 1-2 ). Since then, patient management has improved dramatically, with early surgical mortality decreasing from 50% to less than 2% , so that 90% of the operated patients will survive at least the first two decades of life . As a result, the number of patients with rTOF is growing, and more and more investigations by CMR are requested.
Right ventricular volume and pulmonary regurgitation
The surgical repair consists of ventricular septal defect closure with enlargement of the right ventricular outflow tract (RVOT) by patch insertion. The abnormalities encountered are summarized in Table 1 . The most frequent residual lesion is free pulmonary regurgitation leading to RV dilatation, which is well tolerated during infancy and childhood. The RV compensatory mechanisms tend to fail during the third decade and after, predisposing to arrhythmias, exercise intolerance, heart failure and death . Severe chronic pulmonary regurgitation has been reported to be the main cause of RV dilatation and arrhythmias. The treatment is pulmonary valve replacement, but the optimal timing is still under debate . Criteria for pulmonary valve replacement in rTOF patients include moderate or severe pulmonary regurgitation (regurgitation fraction ≥ 25%), as summarized in Table 2 .
| Secondary to surgical repair |
| Pulmonary regurgitation |
| RVOT scar |
| Ventricular septal defect patch |
| Residual or recurrent lesion |
| RVOT obstruction |
| Branch pulmonary artery stenosis |
| Ventricular septal defect |
| Atrial septal defect |
| Acquired lesion |
| Tricuspid regurgitation |
| RVOT aneurysm |
| Aortic root dilatation |
| Aortic regurgitation |
| Left ventricle dysfunction |
| Associated anomalies |
| Systemic-to-pulmonary artery collateral |
| Aortic branch pattern |
| Asymptomatic patients with two or more of the following criteria |
| RV end-diastolic volume index > 150 mL/m 2 or Z-score > 4 (in patients whose body surface area falls outside published normal data, RV/LV end-diastolic volume ratio > 2) |
| RV end-systolic volume index > 80 mL/m 2 |
| RV ejection fraction < 47% |
| LV ejection fraction < 55% |
| Large RVOT aneurysm |
| QRS duration > 140 ms |
| Sustained tachyarrhythmia related to right heart volume load |
| Other haemodynamically significant abnormalities |
| RVOT obstruction with RV systolic pressure ≥ ⅔ systemic |
| Severe branch pulmonary artery stenosis (< 30% flow to affected lung) not amenable to transcatheter therapy |
| At least moderate tricuspid regurgitation |
| Left-to-right shunt from residual atrial or ventricular septal defects with pulmonary-to-systemic flow ratio ≥ 1.5 |
| Severe aortic regurgitation |
| Severe aortic dilatation (diameter ≥ 5 cm) |
| Symptomatic patients |
| Symptoms and signs attributable to severe RV volume load documented by CMR or alternative imaging modality, fulfilling at least one of the quantitative criteria detailed above. Examples of symptoms and signs include |
| Exercise intolerance not explained by extracardiac causes (e.g. lung disease, musculoskeletal anomalies, genetic anomalies, obesity), with documentation by exercise testing with metabolic cart (≤ 70% predicted peak VO 2 for age and sex not explained by chronotropic incompetence) |
| Signs and symptoms of heart failure (e.g. dyspnoea with mild effort or at rest not explained by extracardiac causes, peripheral oedema) |
| Syncope attributable to arrhythmia |
| Special considerations |
| Due to higher risk of adverse clinical outcomes in patients who underwent TOF repair at age ≥ 3 years , PVR may be considered if the patient fulfils at least one of the quantitative criteria in section I |
| Women with severe PR and RV dilatation and/or dysfunction may be at risk of pregnancy-related complications . Although no evidence is available to support benefit from prepregnancy PVR, the procedure may be considered if the patient fulfils at least one of the quantitative criteria in section I |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
