Investigating the family after a sudden cardiac death Dr Catherine Mercer Consultant Clinical Geneticist, Wessex
Sudden adult deaths subdivided Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death
What is SADS? 0-40 years Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death
Sudden Cardiac Death (0-40 years) Myocarditis Cause identified (60%) Coronary Artery Disease Congenital Heart Disease HCM ARVC DCM Aortopathy Cardiomyopathies
Sudden Cardiac Death (0-40 years) Myocarditis Cause identified (60%) Coronary Artery Disease Congenital Heart Disease HCM ARVC DCM Aortopathy Genetic cause common, typically autosomal dominant
Sudden Cardiac Death (0-40 years) No cause identified 40% Causes include: LQTS Brugada CPVT Genetic cause common, typically autosomal dominant
Sudden deaths that need investigation Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death
Autosomal dominant disease: First Degree Relatives at risk Sudden Adult Death Sudden Cardiac Death Sudden Arrhythmic Death
Review of hospital notes of affected brother: Previously generally fit and well Varicose vein surgery 10 years prior Laparoscopic cholecystectomy Finance manager Married Wife 32 weeks pregnant
Sudden onset chest pain, radiating to jaw and back Continuous Aggravated by movement Seen in A & E, CT scan next morning Aortic root aneurysm, 7cm diameter Type A aortic dissection, extensive
Marfan Syndrome
Genetic testing in deceased brother: Mutation report: c.5999g>c, p.cys2000ser in Fibrillin 1
Mutation report: Heterozygous for a G to
Mutation report: Heterozygous for a G to
Mutation report: Heterozygous for a G to
Mutation Died suddenly report: following a Heterozygous bicycle ride, for aged a G 34 to years, HCM known, no genetic testing
Died in 30s Died in 50s, HCM reported by family Mutation Died suddenly report: following a Heterozygous bicycle ride, for aged a G 34 to years, HCM known, no genetic testing
Hospital notes review: Numerous letters from 1980s confirming diagnosis of HCM Died in 30s Died in 50s, HCM reported by family Mutation Died suddenly report: following a Heterozygous bicycle ride, for aged a G 34 to years, HCM known, no genetic testing
Died in 30s Died in 80s, HCM reported by family Mutation DNA extracted report: post Heterozygous mortem, testing for a underway G to
Issue date: August 2008 Identification and management of familial hypercholesterolaemia
Died following out of hospital VF arrest, age 40, known history of hypertension, raised BMI Mutation report: Heterozygous for a G to
Review of medical notes from affected mother: No prior history of cardiac disease Cardiac arrest at home, resuscitated, cardioverted, LBBB Angiogram: NAD CT head: NAD Clinical diagnosis: cardiac arrest, hypoxic brain injury
Review of post mortem: This is sudden cardiac death due to left ventricular hypertrophy with myocyte hypertrophy and fibrosis in keeping with hypertensive disease Normal cardiomyocyte histology Cardiomyocyte disarray
Died following out of hospital VF arrest, age 40, known history of hypertension, raised BMI Mutation No genetic report: testing indicated Heterozygous for a G to
Dilated Idiopathic Cardiomyopathy Genetic Drugs/ Toxins Infection Immune
Died from heart failure, known DCM, age 37 years
Died from heart failure, known DCM, age 37 years
Sudden Cardiac Death cause identified Targeted history and clinical investigations Genetic testing if DNA available Screening begins with First Degree Relatives (FDRs) of deceased
SCD vs SADS Sudden Cardiac Death Sudden Arrhythmic Death SADS: negative postmortem
The negative PM No other cause of death identified Structurally normal heart No abnormal histopathological findings in the heart Normal blood toxicology screen No pre-death clinical features to suggest other causes of sudden death Cause of death may be genetic
Sudden Arrhythmic Death (0-40 No cause identified 40% years) LQTS Brugada CPVT
Long QT Syndrome HCM DCM
Long QT Syndrome HCM DCM
Brugada Syndrome ST segment abnormalities in leads V1-V3 Diagnosis difficult: may need Ajmaline challenge HCM Risk of ventricular arrhythmias Typical presentation is in adulthood DCM
Brugada Syndrome ST segment abnormalities in leads V1-V3 Diagnosis difficult: may need Ajmaline challenge HCM Risk of ventricular arrhythmias Typical presentation is in adulthood DCM Philippines: Bangungut scream followed by death during sleep Thailand: Lai Tai death during sleep Japan: Pokuri unexpected death during sleep
Catecholamineragic Polymorphic Ventricular Tachycardia Episodic syncope due to fast VT HCM May degenerate into ventricular fibrillation Typical presentation is in childhood Around 30% present with sudden death DCM Diagnosis: typically via exercise test
Died while swimming, age 31 years. Negative post mortem. No DNA available.
Investigations of relatives ECG Echo HCM Exercise test Holter monitor DCM Cardiac MR Ajmaline challenge
Investigations of relatives
Died while swimming, age 31 years. Negative post mortem. DNA available.
Molecular autopsy HCM DCM Semsarian et al.
Mutation identified; cascade test in family members.
The role of genetic testing in Sudden Adult Death May identify pathogenic mutation: - gives certainty about diagnosis - allows cascade screening of relatives Blind testing not useful in relatives
Why isn t genetic testing the magic bullet in SADS cases?
Why isn t genetic testing the magic bullet in SADS cases?
Comparing 3,000,000,000 base pairs compared to the standard 3,000,000,000 base pairs. 6,400,000 differences 700,000 will be rare 3000 would affect a protein Is the variant shared by other affected family members? Has the gene/variant been linked to similar symptoms
Assessment of the family in cases of young sudden death Family history Explore hospital records from affected individual, including post mortem Establish if DNA has been stored or not Screen first degree relatives; targeted where possible, ideally in specialist clinic Discuss genetic testing with the family if DNA available
The role of the GP Take family history Encourage DNA storage Baseline screen (symptoms, ECG) Refer to Cardiology and Clinical Genetics (Explore hospital records from affected individual, including post mortem)
Idiopathic Arrhythmogenic Right Ventricular Cardiomyopathy
The role of the GP Take family history Encourage DNA storage Baseline screen (symptoms, ECG) Refer to Cardiology and Clinical Genetics (Explore hospital records from affected individual, including post mortem)