How should I approach the investigation of a family history of sudden cardiac death in a young patient?

When investigating a family history of sudden cardiac death in a young patient, your approach should involve a thorough family history assessment and consideration of potential underlying conditions, such as familial hypercholesterolaemia (FH), which can lead to premature cardiac events ¹.

• Gather a Detailed Family History: You should draw a pedigree that includes at least three generations, documenting illnesses, hospitalisations, causes of death, miscarriages, abortions, congenital anomalies, and any other unusual features ¹. It is crucial to identify first-degree relatives (biological parents, brothers, sisters, and children) and second-degree relatives (biological grandparents, grandchildren, uncles, aunts, nieces, nephews, half-sisters, or half-brothers) ¹. Note any instances of premature coronary heart disease, defined as a coronary event occurring before 60 years of age in an index individual or first-degree relative ¹. Understanding the cause of sudden cardiac death in affected family members, potentially through forensic investigation details, is also important ((Oliva et al., 2011)).
• Assess for Familial Hypercholesterolaemia (FH): If the young patient has a family history of coronary heart disease in early adulthood, or two or more other cardiovascular risk factors (e.g., male sex, smoking, hypertension, or diabetes), consider offering a referral for evaluation of coronary heart disease ¹. A structured review should include an assessment of any symptoms of coronary heart disease, smoking status, and a fasting lipid profile ¹.
• Referral Pathways:
  • If the young patient with a family history of sudden cardiac death has symptoms or signs of possible coronary heart disease that are not immediately life-threatening, an urgent referral (within a maximum of 14 days) to a specialist with expertise in cardiology for evaluation is recommended, with a low threshold for referral ¹.
  • For symptoms or signs that are immediately life-threatening (e.g., acute coronary syndrome), the patient should be referred to hospital as an emergency ¹.
  • For children and young people diagnosed with homozygous FH, a referral for an evaluation of coronary heart disease should be offered upon diagnosis ¹.
  • In asymptomatic children and young people with heterozygous FH, routine referral for evaluation of coronary heart disease is generally not recommended, as it is unlikely to detect clinically significant disease ¹.
• Genetic Considerations: While the provided context primarily focuses on FH, the principle of genetic assessment for familial conditions is highlighted in other guidelines, such as for ovarian cancer, where genetic counselling and testing are offered based on family history and cascade testing ². For FH, if a disease-causing mutation has been identified in an index individual, DNA testing is used for cascade testing in relatives ¹.