Clinical Electrophysiology -> SCA Risk Assessment: -> Clinical Risk Assessment Techniques D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-214 - Nocturnal Sudden Death In The General Population (ID 499)

 A. Uy-Evanado: Nothing relevant to disclose.


Background: With reduction in both heart rate and blood pressure, as well as absence of daytime triggers, the pathophysiology of sudden cardiac arrest (SCA) during sleep is poorly understood. Individuals who suffer SCA during sleep may have unique substrates and triggers.
Objective: We hypothesized that hypoxia is a trigger for nocturnal SCA, and is associated with specific disease conditions and medications that have adverse effects on breathing.
Methods: From the ongoing population-based Oregon Sudden Unexpected Death Study (catchment population approx. 1 million, 2002-2015), we evaluated subjects who suffered SCA between 12 midnight and 6 AM (nocturnal cases) and made comparisons with those that occurred during the remaining 18 hours (daytime cases). Time of SCA was determined by the 911 call and review of circumstances provided by the emergency medical services. A detailed review of all available lifetime clinical history was conducted. Univariate comparisons were evaluated using Pearson’s chi-square tests and independent samples t-tests. Logistic regression was used to assess the independent SCA risk of comorbidities and medications.
Results: A total of 4009 SCA cases were included in the analysis. Compared to daytime cases (n=3393), nocturnal cases (n=616, 15.4%) were more likely to be female (40 vs 33%, p=0.002) but were similar in age (65 vs 66 y) and body habitus (obese 31 vs 29%, p≤0.28). Nocturnal cases were more likely to have bipolar disorder, depression, COPD/asthma, diabetes mellitus, chronic pain, and anemia (p≤0.05). Central nervous system (CNS) affecting drugs (psychotropics, anti-depressants, benzodiazepines, anti-epileptics) and beta-blockers were more commonly prescribed in the nocturnal cases (p≤0.05). In a logistic regression model, female sex [OR 1.3 (1.1-1.6)], COPD/asthma [OR 1.4 (1.1-1.7)], CNS medications [OR 1.3 (1.04-1.6)] and beta-blockers [OR 1.3 (1.04-1.5)] were significantly and independently associated with nocturnal SCA.
Conclusion: These findings suggest that hypoxia is a likely trigger for nocturnal SCA and that CNS-affecting drugs should be prescribed cautiously in high risk patients. The associations with female sex and COPD warrant further evaluation.