Pauline Quenin (I’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France) and others report in Circulation Arrhythmia and Electrophysiology that a quarter of families who underwent screening after the sudden unexplained death of a young relative were diagnosed with an inherited arrhythmia syndrome. They add that screening identified arrhythmias even whne an autopsy on the young relative had not been performed.
The authors note that current European Society of Cardiology (ESC)/Heart Rhythm Society (HRS) guidelines recommend that familial screening is performed following a negative autopsy of a young person—aged younger than 45 years—who had an unexplained sudden cardiac death. However, they comment medical autopsy after sudden cardiac death “in a large majority of countries” is rare. The aim of the present study, therefore, was to evaluate the efficacy of familial screening after an unexplained sudden cardiac death in a person aged younger than 45 years even in the absence of autopsy.
Of 64 families who underwent screening, 16 (25%) were diagnosed with an inherited arrhythmia syndrome—including seven with Brugada syndrome, five with long QT syndrome, two with dilated cardiomyopathy, and two with hypertrophic cardiomyopathy. Quenin et al comment: “However, in studies performed after negative autopsy in the proband, diagnostic accuracy was higher reaching 40% to 53% of the families.”
Also, they state the diagnosis rate increased with the number of family members screened: 3.8±3.4 screened relatives vs. 2±1.5 (p<0.005), with the rate being 47% when at least three relatives were screened. “It additionally increased from three of 32 (9%) to nine of 22 (41%) when both parents were screened (p=0.01),” the authors observe. Furthermore, they comment: “Diagnostic performance was also dependent on the exhaustiveness of screening (70% of complete screening in the diagnosed families vs. 25%; p<0.0001) with 17 Brugada syndromes and 15 long QT syndromes diagnosed based on pharmacological tests.”
Study author Jean-baptiste Gourraud (I’institut du thorax, INSERM, CNRS, UNIV Nantes, CHU Nantes, Nantes, France) told that Cardiac Rhythm News that the two main findings of the study were that: “It is possible to identify a familial arrythmia disease even when no medical autopsy had been performed (and thus family with an old history of sudden cardiac death in a young adult may perform a cardiac screening), and that Ajmaline test should be always performed during the screening even when ECG do not presented abdnormalities.”