Aftershock Triggers Augmented Pressor Effects in Survivors: Follow-Up of the Great East Japan Earthquake

Abstract

Background Previous reports focused on the significant acute effects immediately after an earthquake on an increase in blood pressure (BP) assessed by ambulatory BP monitoring. However, there have been no data on the impact of environmental triggers on the long-term response to earthquake. Methods We analyzed the ambulatory BP monitoring data of 8 patients who lived in the disaster area of the 11 March 2011 Great East Japan Earthquake on the day of the largest aftershock with a first tsunami warming (sirens) on 7 December 2012. Results There was no significant difference in the BP in either the period 1 hour before (median (range): 126.5 (121.5-138.0) vs. 137.8 (129.5-177.0) mm Hg, P = 0.07) or that 1 hour after (139.3 (113.0-143.5) vs. 137.5 (125.0-192.0) mm Hg, P = 0.27) the aftershock between those living at home and those who had been living in temporary housing. After the time of aftershock, the systolic BP levels at that night (124.9 (113.2-137.9) vs. 107.0 (101.9-110.1) mm Hg, P = 0.021) and systolic BP levels at the following morning (149.3 (131.0-196.2) vs. 129.5 (128.8-131.0) mm Hg, P = 0.029) were also significantly higher in those living in temporary housing at the time compared to those living in their own homes. Conclusion Our data suggest that the stress of a change in living conditions following the disaster might have contributed an increased risk of cardiovascular events.