A Population-Based Registry of Patients With Inherited Cardiac Conditions and Resuscitated Cardiac Arrest

Background: The relative proportion of each cardiac inherited disease (CID) causing resuscitated sudden cardiac arrest (RSCA) on a population basis is unknown.

Objectives: This study describes the profile of patients with CIDs presenting with RSCA; their data were collected by the national Cardiac Inherited Diseases Registry New Zealand (CIDRNZ).

Methods: Data were collated from CIDRNZ probands presenting with RSCA (2002 to 2018).

Results: CID was identified in 115 (51%) of 225 RSCA cases: long QT syndrome (LQTS) (n = 48 [42%]), hypertrophic cardiomyopathy (HCM) (n = 28 [24%]), Brugada syndrome (BrS) (n = 16 [14%]), catecholaminergic polymorphic ventricular tachycardia (CPVT) (n = 9 [8%]), arrhythmogenic right ventricular cardiomyopathy (ARVC) (n = 9 [8%]), and dilated cardiomyopathy (n = 5 [4%]). Seventy-one (62%) of 115 were male. Of 725 probands from the CIDRNZ with CID, the proportion presenting with RSCA was: CPVT, 9 (53%) of 17; BrS, 16 (33%) of 49; ARVC, 9 (25%) of 36; LQTS, 48 (20%) of 238; dilated cardiomyopathy, 5 (9%) of 58; and HCM, 28 (8%) of 354. Incident activity was: normal everyday activities, 44 (40%); exercising, 33 (30%); concurrent illness, 13 (12%); sleeping, 10 (9%); drugs/medication, 9 (8%); and emotion, 2 (2%). LQTS and CPVT predominated in those <24 years of age, 30 (77%) of 39; cardiomyopathies and BrS predominated in those >24 years of age, 49 (64%) of 76. For those >40 years of age, HCM was the most common (33%) CID. A genetic diagnosis in patients with CID was made in 48 (49%) of 98 tested. Diagnosis by age range was as follows: age 1 to 14 years, 78%; age 15 to 24 years, 53%; age 25 to 39 years, 54%; and age >40 years, 26%.

Conclusions: The commonest CID identified after RSCA was LQTS; the most common CID cause of RSCA for those >40 years of age was HCM. CPVT was the CID most likely to present with RSCA and HCM the least. Genetic yield decreases with age. Only one-third of RSCA cases due to CID occurred while exercising.