Sudden death is always an unexpected and devastating occurrence. The
normal electrophysiological behavior of the human heart is determined by an ordered
propagation of excitatory stimuli that result in slow repolarization and a rapid
depolarization, thereby, generating action potential in each myocyte. Hence, mutations
in or involving cardiac ion channels result in an abnormal propagation or action
potential formation, leading to cardiac arrhythmias. Despite the worrisome impact of
sudden cardiac death, and sudden infant death syndrome in the society resulting from
such arrhythmias, knowledge of the underlying cellular mechanism is poor, and
treatment is consequently and continuously limited. This chapter aims to focus on the
role of basic science (current diagnostic and therapeutic options) in investigating
primary electrical cardiac diseases as a paradigm for cardiac arrhythmias, concentrating
on the long-QT syndrome, Brugada syndrome, and catecholaminergic polymorphous
ventricular tachycardia. Also, the underlying pathology and physiology of ion channel
diseases are described associated with sudden infant death syndrome to provide a
clinical perspective of cardiac channelopathies about sudden infant death syndrome.
The learning objectives of the chapter would enable practicing physicians/clinicians in
the field to:
I. Recognize risk factors, signs, and symptoms that should prompt suspicion of a
congenital arrhythmia syndrome,
II. Explain the treatment options, list measures to prevent sudden cardiac death and
sudden infant death syndrome, and
III. Finally, describe what can be achieved with molecular genetic diagnostic tests and
thereby, comfortably list the difficulties and limitations of interpreting genetic results.
Keywords: Arrhythmias, Atrial Fibrillation, Adolescents, Brugada Syndrome,
Cardiomyopathy, Cardiology, Channelopathies, Death, Exercise, Genetics,
Genetic arrhythmias, Gene-Specific Management, Genetic Testing, Heart, Heart
Rhythm Disorders, Infant, Inherited Arrhythmic Disorders, Ion Channel Structure,
Ion Channel Function, Ischemic Heart Disease, Pathology of Sudden Cardiac
Death, Pathophysiology of Sudden Cardiac Death, Primary Electrical Cardiac
Channelopathies, Sudden Death, Sudden Infant Death Syndrome, Susceptibility
Genes, Syncope, Ventricular Fibrillation.
