[Sudden cardiac death: the seven questions all cardiologists must answer to]

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Context:

• Sudden cardiac arrest (SCA) remains a significant concern, with incidence rates varying globally.
• While severe heart disease and low ejection fraction are known risk factors, a substantial portion of SCA cases occur in individuals with no apparent cardiac history or normal left ventricular function.
• The role and indications for implantable cardioverter-defibrillators (ICDs) in SCA prevention are subjects of ongoing clinical discussion and research.

Purpose:

• To address key questions surrounding the prevention and treatment of sudden cardiac arrest (SCA).
• To clarify the indications for implantable cardioverter-defibrillators (ICDs) in diverse patient populations.
• To evaluate the utility of electrophysiology (EP) testing in SCA risk stratification.

Summary:

• Worldwide, SCA incidence ranges from 100 to 750 per million inhabitants.
• Approximately 75% of SCA cases lack significant cardiac history or present with normal left ventricular function, challenging traditional risk stratification.
• Electrophysiology testing is generally not recommended for SCA risk stratification, except in specific circumstances. Family history and ECG abnormalities (e.g., delta wave, long QT interval) may indicate risk in individuals without prior heart disease.

Impact:

• The implantable cardioverter-defibrillator (ICD) remains the most effective therapy for preventing and treating sudden cardiac arrest (SCA), despite potential risks like inappropriate shocks.
• Understanding risk factors beyond severe heart disease is crucial for optimizing ICD implantation strategies.
• This review provides insights into current debates regarding SCA management and the evolving role of ICDs in clinical practice.