Background: Sudden Cardiac Death (SCD) remains a major public health concern, accounting
for more than 50% of cardiac deaths. The majority of these deaths are related to ischemic
heart disease, however increasingly recognized are non-ischemic causes such as cardiac channelopathies.
Bradyarrhythmias and pulseless electrical activity comprise a larger proportion of out-ofhospital
arrests than previously realized, particularly in patients with more advanced heart failure or
noncardiac triggers such as pulmonary embolism. Patients surviving Sudden Cardiac Arrest (SCA)
have a substantial risk of recurrence, particularly within 18 months post event. The timing of tachyarrhythmias
complicating acute infarction has important implications regarding the likelihood of
recurrence, with those occurring within 48 hours having a more favorable long-term outcome. In
the absence of a clear reversible cause, implantable cardioverter defibrillators remain the mainstay
in the secondary prevention of SCD. Post defibrillation electromechanical dissociation is common
in patients with cardiomyopathy and can lead to SCD despite successful defibrillation of the primary
tachyarrhythmia. Antiarrhythmic agents are highly effective in preventing recurrent arrhythmias
in specific diseases such as the congenital long QT syndrome.
Conclusion: Catheter ablation is used most commonly to prevent recurrent ICD therapies in patients
with structural heart disease-related ventricular arrhythmias, however recent publications
have shown substantial benefit in other entities such as idiopathic ventricular fibrillation.
Keywords: Electrophysiologic considerations, cardioverter defibrillators (ICDs), coronary artery disease, mortality, sudden
cardiac arrest, survival.
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