Is MRI the Preferred Method for Evaluating Right Ventricular Size and Function in Patients With Congenital Heart Disease?Response to Geva
MRI Is the Preferred Method for Evaluating Right Ventricular Size and Function in Patients With Congenital Heart Disease
In contrast to adult patients with acquired heart disease, abnormalities of the right ventricle (RV) are ubiquitous in children and adults with congenital heart disease (CHD). The RV is exposed to volume overload in shunt lesions (eg, atrial septal defect, anomalous pulmonary venous connections), as well as congenital or acquired tricuspid and pulmonary valve regurgitation. RV pressure overload characterizes numerous congenital anomalies, including pulmonary valve stenosis or atresia, large ventricular septal defect, single ventricle, tetralogy of Fallot (TOF), truncus arteriosus, and transposition of the great arteries, to name a few. Importantly, many surgical and transcatheter treatments of CHD result in persistent or acquired volume and pressure overload of the RV. In some patients with CHD, the RV functions as the systemic ventricle (eg, palliated hypoplastic left heart syndrome, physiologically corrected transposition of the great arteries, and D-loop transposition of the great arteries after atrial switch procedure). Furthermore, exposure to cyanosis and surgical procedures in the RV often leads to myocardial abnormalities, including scar tissue and diffuse fibrosis.
Response by Yeh and Foster see p 197
Given the frequent involvement of the RV in CHD, it is not surprising that the assessment of RV size and function is key for guiding clinical decisions in these patients.1 Among the diagnostic imaging tools available to clinicians for RV imaging, cardiac magnetic resonance (CMR) has emerged as the reference standard. In the following sections, I will review the evidence supporting this contention, highlight how CMR data are used to guide clinical decisions, and discuss the strengths and weaknesses of CMR in comparison with other modalities, including echocardiography, computed tomography, conventional x-ray angiography, and nuclear scintigraphy.
Versatility of CMR
CMR is ideally suited for the assessment of the RV because it allows comprehensive assessment of cardiovascular morphology and physiology without most of the limitations that hinder alternative …