Over time, a significant increase in heart attacks in the first four days after a major earthquake has been observed, according to the secretary general of the Hellenic Heart Foundation (ELIKAR), Dimitris Richter.
Speaking to the FM news agency, Richter said acute stress is linked to the likelihood of heart attack.
“When we fill our body with adrenaline, it is likely to rupture an atherosclerotic plaque,” he explained.
“At the same time, there is a spasm of the blood vessel, so we secrete a flood of hormones…[hence, ] the more vulnerable or unlucky someone is, the more the chances of an acute episode,” he underscored.
The Greek scientist noted that the best records we have on the link between heart attacks and earthquakes are from the 1981 earthquake in Greece and the 1994 Los Angeles earthquake.
In both cases, there was a huge increase in heart attacks over the next two to four days.
Heart attacks increased after the 1981 earthquakes in Greece
In early 1981, the eastern Gulf of Corinth, Greece was struck by three earthquakes with a magnitude greater than 6.0 over a period of eleven days. The series of earthquakes caused widespread damage in the Corinth–Athens area, destroying nearly eight thousand homes and resulting in twenty to twenty-two deaths.
In a study published in The Lancet, by Professor Dimitrios Trichopoulos, the effect of the earthquake on heart attacks was investigated by comparing total and cause-specific mortality during the days after a major earthquake in Athens in 1981 with the mortality rate of the rest of the month and corresponding periods of 1980 and 1982.
There was an excess of deaths from cardiac and external causes on the days after the major earthquake but no excess of deaths due to cancer and little, if any, excess of deaths from other causes.
The excess mortality was more evident when atherosclerotic heart disease was considered as the underlying cause (5, 7, and 8 deaths on the first three days, respectively; background mean deaths per day 2.6;) than when cardiac events, in general, were considered as the proximate cause (9, 11, and 14 deaths on the first three days, respectively; background mean 7.1).
Heart attacks during LA 1994 earthquake
Similar conclusions were reached in the aftermath of the 1994 Northridge earthquake in Los Angeles.
The death toll was fifty-seven, with more than nine thousand injured. In addition, property damage was estimated to be thirteen to fifty billion dollars—equivalent to twenty-four to ninety-three billion dollars in 2021. This made the Los Angeles earthquake one of the costliest natural disasters in U.S. history.
In a study published in the New England Journal of Medicine, scientists found that, on the day of the earthquake, there was a sharp increase in the number of sudden deaths from cardiac causes that were related to atherosclerotic cardiovascular disease—from a daily average of 4.6 in the preceding week to twenty-four on the day of the earthquake.
Sixteen victims of sudden death either died or had premonitory symptoms, usually chest pain, within the first hour after the initial tremor. Only three sudden deaths occurred during or immediately after unusual physical exertion. During the six days after the earthquake, the number of sudden deaths declined to below the baseline value to an average of 2.7, the study found.