Noninvasive Cardiac Imaging Recommendations for Noninvasive Cardiac Imaging Referenced studies that support the recommendations are summarized in Online Data Supplement 6. COR LOE Recommendations I B-NR In patients with known or suspected VA that may be associated with underlying structural heart disease or a risk of SCA, echocardiography is recommended for evaluation of cardiac structure and IIa C-EO In patients presenting with VA who are suspected of having structural heart disease, cardiac magnetic resonance imaging (MRI) or computed tomography (CT) can be useful to detect and characterize underlying structural heart disease. Recommendation-Specific Supportive Text 1. Assessment of global and regional myocardial function, valvular structure and function, along with assessment for adult congenital heart CLINICAL STATEMENTS AND GUIDELINES disease is required in patients with or at high risk for VA or SCD, including patients with cardiomy- opathy, HF, prior MI, family history of cardiomy- opathy or SCD, or an inherited structural heart disease associated with SCD. Echocardiography is the most readily available and commonly used LVEF is a strong, independent predictor of SCD and cardiovascular mortality and a determinant of eligibility for ICD implantation for primary prevention of SCD.S4.2.4-1 In SCD-HeFT (the Sudden Cardiac Death in Heart the benefit of the ICD was not dependent on the modality (ie, echocardiogra- phy, radionuclide angiography, or contrast angio- grams) by which the LVEF was assessed. In clinical practice, if cardiac CTS4.2.4-3 or cardiac MRI has been performed and provides sufficient evalua- tion, echocardiography may be unnecessary. This recommendation for imaging differs from that of the 2017 ACC/AHA/HRS syncope guidelineS4.2.4-4 that applies to patients who may not have VA. 2. VA or SCA can be an initial manifestation of isch- emic heart disease, cardiomyopathic processes, or myocarditis. 