Noninvasive Imaging in Interventional Cardiology: Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a spectrum of left heart underdevelopment leaving the left side unable to support the systemic circulation. If active management is pursued, then the condition is managed with staged palliation to the Fontan circulation, leaving a systemic right ventricle. Through all surgical stages, and even after completion of Fontan, there are multiple areas that may require intervention, most frequently the branch pulmonary arteries which are essential to a successful Fontan circulation. Echocardiography is the mainstay of assessment, but there is an increasing use of magnetic resonance imaging (MRI) and computed tomography (CT) particularly in relation to extracardiac structures which can be more challenging with echocardiography. Both MRI and CT require set-up, experience and training, and usually sedation or anesthetic in smaller children, but can provide excellent imaging to guide interventions. Cardiac MRI is also able to quantify right ventricular (RV) function which can be challenging on echocardiography. This article describes the modalities available and their use in assessing patients with HLHS prior to catheter interventions.

Automated summary

Hypoplastic left heart syndrome is a spectrum of left heart underdevelopment that requires staged palliation to the Fontan circulation for management, with potential long-term intervention needed for the branch pulmonary arteries. Echocardiography is the mainstay for assessment, but MRI and CT are increasingly used for more challenging extracardiac structures. Both MRI and CT require specific conditions and training, but can provide excellent imaging guidance for interventions.