Rising cardiovascular incidence after Japanese earthquake 2011

August 27, 2012

The Japanese earthquake and tsunami of 11 March 2011, which hit the north-east coast of Japan with a magnitude of 9.0 on the Richter scale, was one of the largest ocean-trench earthquakes ever recorded in Japan. The tsunami caused huge damage, including 15,861 dead and 3018 missing persons, and, as of 6 June 2012, 388,783 destroyed homes.

Following an investigation of the ambulance records made by doctors in the Miyagi prefecture, close to the of the and where the damage was greatest, cardiologist Dr Hiroaki Shimokawa and colleagues from the Tohoku University Graduate School of Medicine at Sendai, Japan, found that the weekly occurrence of five conditions - heart failure, (including and acute MI), stroke, cardio-pulmonary arrest and pneumonia - all increased sharply soon after the earthquake occurred.

Such reactions - in ACS, stroke and - have been reported before, said Dr Shimokawa, in Japan, China and the USA. However, these studies reported only the short-term occurrence of individual CVD events, and the mid-term CVD effects of such great earthquakes remain to be elucidated. To this end, the study examined all ambulance transport records in the Miyagi prefecture from 11 February to 30 June for each year from 2008 to 2011 (ie, four weeks before to 16 weeks after 11 March, a total of 124,152 records). Incidence records from before, during and after the earthquake disaster were compared, the counted and recorded according to a seismic intensity of 1 or greater.

The number of aftershocks in the Miyagi prefecture was frequent during the six weeks after the earthquake, and the second peak was noted as a large aftershock on 7 April 2011 (magnitude of 7.0). Compared with the previous three years, the significant increases in the occurrence of heart failure and pneumonia were steadily prolonged for more than six weeks after the tsunami struck. On the other hand, the incident increases in stroke and cardio-pulmonary arrest followed the pattern of the first and aftershock seismic peaks. The rapid increases in the occurrence of acute coronary syndromes and cardio-pulmonary arrest was followed by a sharp and significant decline. Interestingly, said Dr Shimokawa, age, sex or residence area did not significantly affect the occurrences of CVD during or following the tsunami.

"To the best of our knowledge," he added, "this is the first report to describe the mid-term course of major and pneumonia after a great earthquake in a large population. In particular, our findings provide the first evidence that the incidence of heart failure was markedly increased over a long period afterwards." Prevalence of pneumonia, a well known risk factor for deteriorating , was significantly increased.

The Tohoku University study also found - as reflected in self-monitoring measurements - that blood pressure was significantly elevated after the Earthquake. However, transport disruption following the tsunami interrupted delivery of regular medications, such as antihypertensive or antithrombotic drugs, and this may have contributed to the increased cardiovascular events. There was also an increase in the occurrences of ventricular tachyarrhythmias in patients with implantable cardiac defibrillators.

"Taken together," said Dr Shimokawa, "we consider that discontinuation of drugs, activated sympathetic nervous system, rising blood pressure, and the increased occurrence of tachyarrhythmia and infections were all involved in the increased occurrence of cardiovascular events after the Great Earthquake of Japan."

Related Stories

Recommended for you

Artificial heart design features porous plastic foam

October 2, 2015

Artificial hearts with multiple moving parts increase the chance of failure; scientists have worked up a device which is a single piece. No less interesting is the material they used; the team is taking a page out of soft ...

What powers the pumping heart?

September 25, 2015

Researchers at the Ted Rogers Centre for Heart Research have uncovered a treasure trove of proteins, which hold answers about how our heart pumps—a phenomenon known as contractility.

Sticky gel helps stem cells heal rat hearts

September 24, 2015

A sticky, protein-rich gel created by Johns Hopkins researchers appears to help stem cells stay on or in rat hearts and restore their metabolism after transplantation, improving cardiac function after simulated heart attacks, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.