Inherited cardiac conditions and sudden cardiac death

Synopsis

Identify inherited cardiomyopathy and channelopathy red flags, investigate sudden unexplained death and organise expert family screening.

• Think inherited disease with young sudden death, exertional syncope, unexplained seizure-like episodes, cardiomyopathy, characteristic ECG changes or multiple affected relatives.
• Construct a three-generation pedigree and verify diagnoses/death circumstances where possible.
• A normal resting ECG and echo do not exclude a channelopathy or early cardiomyopathy.
• First-degree relatives after sudden unexplained death should receive clinical screening through an NHS inherited-cardiac-conditions service.
• Genetic testing starts with an appropriately phenotyped affected proband or retained post-mortem DNA when possible, with pre- and post-test counselling.
• A pathogenic or likely pathogenic variant can enable predictive cascade testing; a variant of uncertain significance must not be used alone for predictive diagnosis.
• Risk-reduction advice is condition-specific: exercise, fever, medicines, electrolytes, pregnancy and ICD decisions cannot be generalised across all inherited conditions.