Multimodal Echocardiographic Assessment in Intravenous Immunoglobulin-Resistant Kawasaki Disease: From Prediction to Long-Term Surveillance.

Kawasaki disease (KD) with intravenous immunoglobulin (IVIG) non-response is a high-risk state in which fever response, coronary evolution, and myocardial dysfunction may diverge. This narrative review, appraised against SANRA after drafting, examines echocardiography across the disease-management lifecycle, from pre-treatment risk enrichment to long-term surveillance. PubMed/MEDLINE searches were supplemented by cross-source discovery and metadata verification. Standardized serial coronary measurement with consistent use of one Z-score system remains the management core. Initial composite echocardiographic abnormalities, myocardial deformation, and tissue-Doppler indices may enrich risk assessment, but current discrimination is moderate and thresholds lack external validation. IVIG non-response and coronary aneurysm are related but non-interchangeable; defervescence does not establish coronary safety, whereas definite baseline coronary artery aneurysm is a treatment-relevant high-risk phenotype. Deformation, myocardial work, right-heart indices, coronary flow reserve, and complementary imaging can refine selected clinical questions but should not trigger treatment in isolation. Echocardiography can therefore structure coronary and myocardial surveillance, but cannot yet independently determine treatment resistance or support a universal multimodal treatment score. Prospective multicenter standardization, external validation, and clinical-utility testing are required before multimodal imaging-guided treatment decisions are adopted.