Background: Recognising the aetiology of sudden cardiac arrest (SCA) has an enormous impact on the management of victims and their immediate families. Despite advances in cardiac investigations, a large proportion of SCA survivors are not offered a diagnosis for such a life changing event. Although there is support for monitoring such patients, there is no clear consensus on the type and duration of follow-up. It is plausible that some patients initially labelled as Idiopathic ventricular fibrillation develop phenotypic features of inherited cardiac disease or exposure to specialists in dedicated inherited cardiac disease clinics overturn a previously unknown diagnosis. The role of the multidisciplinary team in managing survivors of SCA is poorly reported in the literature.
Methods: We assessed consecutive patients who underwent secondary prevention internal cardiac defibrillators (ICD) for SCA between May 2015 and November 2018 at a large tertiary centre. The initial diagnosis was recorded from records at the time of admission and follow up diagnosis and outcomes were deduced from clinic records and outcomes of multidisciplinary team (MDT) meetings.
Results: Twenty-seven SCA arrest survivors underwent secondary prevention ICDs including 266 (79.8%) males and 66 (20.2%) females with a mean age of 61.9 ± 16.2 years. Structural heart disease in the form of ischaemic heart disease, cardiomyopathies or congenital heart disease accounted for 86% of SCAs. Forty-five (14%) patients had a structurally normal heart and underwent comprehensive diagnostic testing. On initial evaluation, the majority of these, 31 (69%) did not have a definitive diagnosis. During a mean follow-up duration of 92.5 (± 51.7) weeks (range 12–166 weeks), 8 (26%) of this cohort had a new established diagnosis for the index SCA. No additional diagnosis was made beyond 92 weeks. Seven (15.6%) patients who had a structurally normal heart received either an appropriate shock or anti-tachycardia pacing (ATP) from their defibrillator device. The mean therapy rate in these patients was 2.7 ± 1.6 occurring on average at 28 ± 16 weeks. Four of these patients did not have a diagnosis for their initial SCA. There were no reported fatalities in the entire cohort during the follow-up period.
Conclusion: Systematic comprehensive testing and follow-up offers a diagnosis in around a half of SCA survivors without structural heart disease. In a tertiary centre with access to specialists working as part of a multidisciplinary team, a shorter duration of follow-up is required to obtain a diagnosis compared to previously published studies. This has positive implications in the management of victims of SCA survivors and their families.