Noninvasive imaging markers associated with sudden cardiac death

Area of Science:

• Cardiology
• Medical Imaging
• Preventive Medicine

Background:

• Sudden cardiac death (SCD) accounts for 15-20% of global deaths, affecting adults and occasionally younger individuals.
• Implantable cardioverter-defibrillators (ICDs) are effective for SCD prevention, but patient selection remains a challenge.
• Left ventricular ejection fraction (LVEF) is a common but suboptimal predictor for ICD benefit.

Purpose of the Study:

• To discuss the role of non-invasive cardiac imaging in risk stratification for SCD.
• To explore how advanced imaging can improve the selection of candidates for ICD implantation.
• To highlight the evolving strategies beyond LVEF for predicting SCD risk.

Main Methods:

• Review of current non-invasive cardiac imaging techniques for characterizing the arrhythmogenic substrate.
• Analysis of imaging's utility in various cardiomyopathies (ischemic, non-ischemic) and channelopathies.
• Evaluation of imaging for detecting triggers like myocardial ischemia and assessing myocardial scar and innervation.

Main Results:

• Non-invasive imaging can characterize the arrhythmogenic substrate, including electromechanical dispersion, scar, and innervation.
• Imaging approaches vary based on underlying conditions; differentiating infarct zones in ischemic cardiomyopathy versus diffuse fibrosis in non-ischemic types.
• Assessment of mechanical dispersion and potential triggers like ischemia can refine risk stratification.

Conclusions:

• Non-invasive cardiac imaging offers a more comprehensive approach to risk stratifying patients for sudden cardiac death.
• Advanced imaging techniques can identify patients who will benefit from ICD implantation more effectively than LVEF alone.
• Characterizing the arrhythmogenic substrate and potential triggers is crucial for optimizing SCD prevention strategies.