Sudden cardiac death: The role of imaging

Area of Science:

• Cardiology
• Electrophysiology
• Preventive Medicine

Background:

• Sudden cardiac death (SCD) accounts for a fifth of global deaths, often in seemingly healthy individuals.
• Current prevention strategies rely on implantable cardioverter-defibrillators (ICDs), with candidate selection based on left ventricular ejection fraction (LVEF) ≤35%.
• LVEF lacks sensitivity and specificity, necessitating improved methods for identifying at-risk patients.

Purpose of the Study:

• To review non-imaging and imaging modalities for SCD risk stratification.
• To evaluate alternative strategies for identifying patients who would benefit from ICD implantation.
• To highlight methods with incremental value over LVEF.

Main Methods:

• Review of evidence on non-imaging techniques: microvolt T-wave alternans, signal-averaged ECG, QRS fragmentation, and autonomic function tests.
• Review of evidence on imaging techniques: echocardiography, cardiac magnetic resonance, and radionuclide imaging.
• Comparative analysis of these modalities against LVEF for predicting ICD benefit.

Main Results:

• Various non-imaging and imaging modalities demonstrate potential for improved SCD risk stratification.
• These methods offer incremental predictive value beyond the current LVEF threshold.
• Evidence suggests these techniques can better identify individuals likely to benefit from ICD therapy.

Conclusions:

• Current LVEF criteria are insufficient for optimal ICD candidate selection.
• Non-imaging and imaging techniques offer promising alternatives for risk stratification.
• Further research and clinical integration of these advanced methods are needed for effective SCD primary prevention.