Population‐Based Incidence of Sudden Cardiac and Unexpected Death Before and After the 2011 Earthquake and Tsunami in Iwate, Northeast Japan

Abstract

BackgroundThe aim of this study was to evaluate the temporal impact of the 2011 Japan earthquake and tsunami on the incidence of sudden cardiac and unexpected death (SCUD).Methods and ResultsWe surveyed the impact of the disaster on the incidence and clinical characteristics of SCUD in Iwate. To perform complete identification of SCUD for 8 weeks before and 40 weeks after the disaster, medical records and death certificates relevant to SCUD were surveyed in the study area. Compared with the previous year's rate, the incidence (per 10 000 person‐year) of SCUD for the initial 4 weeks after the disaster (acute phase) was double (33.5 vs 18.9), and thereafter the rate returned to the previous level. Significant relationships were found between weekly numbers of SCUD and seismic activity (intensity, r=0.43; P<0.005: frequency, r=0.46; P<0.002). The standardized incidence ratio (SIR) of SCUD in the acute phase was significantly increased compared with that of previous years (1.71, 95% CI 1.33 to 2.16). Increased SIRs were predominantly found in female subjects (1.73, 95% CI 1.22 to 2.37), the elderly (1.73, 95% CI 1.29 to 2.27), and residents living in the tsunami‐stricken area (1.83, 95% CI 1.33 to 2.46). In addition, SIRs for weekdays (1.71, 95% CI 1.28 to 2.24) and nights‐mornings (2.09, 95% CI 1.48 to 2.86) were amplified.ConclusionsThe present results suggest that the magnitude of a disaster, related stress, and population aging may cause a temporary increase in the incidence of SCUD with amplification of ordinary weekly and circadian variations.

The Spectrum of Epidemiology Underlying Sudden Cardiac Death

“…On the day of the Northridge earthquake, there was a sharp increase in the number of SCDs related to CHD, which was followed by an unusually low incidence of CHD deaths in the week after the earthquake. In contrast, in the recent Japan earthquake and tsunami, where multiple aftershocks occurred and the level of devastation was quite high in comparison, the incidence of SCD 135 and OHCA 134 was increased for up to four weeks after the event, particularly among the elderly, and was significantly associated with level of seismic activity 135 . These disasters demonstrate how severe emotional stress may precipitate cardiac events in vulnerable and/or predisposed populations.…”

“…Acute increases in the incidence of SCD have been documented in populations suffering disasters such as earthquakes or wars 132–135 . On the day of the Northridge earthquake, there was a sharp increase in the number of SCDs related to CHD, which was followed by an unusually low incidence of CHD deaths in the week after the earthquake.…”

Acute and chronic psychological stress as risk factors for cardiovascular disease: Insights gained from epidemiological, clinical and experimental studies

“…The body's response after exposure to a sudden and severe stressor such as bereavement (Kaprio et al, 1987), an earthquake (Niiyama et al, 2014;Wu et al, 2014) or a terrorist attack (Allegra et al, 2005;Feng et al, 2006) has been demonstrated to fulfill these criteria and associates with increased incidence of ACS.…”

The control of cardiac ventricular excitability by autonomic pathways

“…The multi-tiered contribution of autonomic tone to cardiac arrhythmia onset is illustrated by numerous striking observations of increased arrhythmia frequency coincident with major psychological stress. These include earthquakes, missile (or threatened missile) attack and in the 9-11 World Trade Centre attacks (Leor et al, 1996;Niiyama et al, 2014;Meisel et al, 1991;Shedd et al, 2004;Steinberg et al, 2004). Eye-catching associations have also been made with the phenomenon of voodoo death and as an explanation for increased arrhythmic events during world cup football supporters (Lester, 2009;Wilbert-Lampen et al, 2008).…”