Structural and Physiological Imaging to Predict the Risk of Lethal Ventricular Arrhythmias and Sudden Death

Highlights

• Risk stratification for the occurrence of lethal VT by EF is an insensitive approach.

• Adjunctive analysis of commonly used imaging modalities for dyssynchrony, LV volumes, and LV mass may improve risk prediction.

• Advanced imaging to quantify myocardial fibrosis (MRI) or assess myocardial sympathetic innervation (PET and SPECT) afford novel approaches to assess risk that are potentially independent of LV function.

• A step-wise approach using clinical variables, biomarkers, and multimodality imaging may provide superior and cost-effective risk stratification for SCA.

Abstract

Identifying patients at risk of sudden cardiac death remains a major challenge in cardiovascular medicine. Advances in cardiovascular imaging have identified several anatomic and functional variables that can be quantified as continuous variables to predict the risk of developing lethal ventricular tachyarrhythmias in patients with depressed left ventricular (LV) systolic function. Some, such as LV mass, volume, and the dyssynchrony of contraction, can be derived from currently available echocardiographic and nuclear imaging modalities. Others require advanced cardiac imaging modalities with quantification of myocardial scar with gadolinium-enhanced cardiac magnetic resonance and myocardial sympathetic denervation using norepinephrine analogs and positron emission tomography or single-photon emission computed tomography offering the most promise. There is an immediate need to develop a sequential cost-effective approach that capitalizes on readily available clinical information complemented with advanced imaging modalities in selected patients to improve risk stratification for arrhythmic death beyond LV ejection fraction.