Family history of sudden cardiac death

Screen first-degree relatives for cardiomyopathies and aortopathies; the ECG finds the channelopathies echo cannot.

Echo approach, step by step

After sudden unexplained death in a young relative, first-degree relatives should be evaluated with history, ECG, echocardiography and further tests as indicated, ideally in a specialised inherited-cardiac-disease clinic [14,38].

  1. LV wall thickness and patternHCM, including apical and mid-ventricular forms (use contrast) [13].
  2. LV size and functionDCM, hypokinetic non-dilated cardiomyopathy, LV non-compaction [14,144].
  3. RVARVC Task Force measurements and regional motion [145].
  4. AortaRoot and ascending aorta (Marfan, Loeys–Dietz, familial aortopathy) [9].
  5. ValvesMVP (arrhythmic), bicuspid aortic valve [38].
  6. Coronary originsAnomalous coronary artery in the young [150].

Causes & echo clues

ConditionEcho clueOther key test
HCMWall ≥13 mm in a relativeGenetics [13,14]
DCM / HNDCDilated or hypokinetic LVGenetics (lamin A/C, filamin C) [14]
ARVCRV regional abnormalityECG, CMR [145,146]
AortopathyDilated root or ascending aortaGenetics, CT/MR [9]
Long QT, Brugada, CPVTNormal echoECG, exercise test, drug challenge [38]
Premature coronary diseaseRegional wall motionLipids, CT calcium score [139]

Clinical pathway to the diagnosis

  1. Obtain the autopsy findings of the deceased(including a molecular autopsy where possible) [38].
  2. First-degree relativesHistory, 12-lead ECG, echo, and exercise ECG and Holter as indicated [38].
  3. Genetic testingIf a pathogenic variant is found in the proband, offer cascade testing [14].
  4. CMRWhen echo is borderline [14].
  5. Repeat screeningPeriodically, because penetrance is age-dependent [13,14].

Clinical pearls & pitfalls

Practical tipThe ECG is often abnormal before the echo in HCM and ARVC, and it is the only clue in channelopathies [38].

Red flags