Professor KIM Ho (Graduate School of Public Health)

Professor KIM Ho (Graduate School of Public Health) found that there is a higher risk of cardiac arrhythmia when there is a greater diurnal range during the change of seasons. Diurnal range is the difference between the daily maximum and daily minimum temperature.

Normally the heart beats 60 to 100 times per minute, and 100,000 times a day. Cardiac arrhythmia is a condition where the heart beats, at irregular intervals, much faster or slower than this regular rate. The severity of the symptoms varies from mild heart palpitations, chest pain, and fainting, to sudden cardiac deaths. Apart from innate conditions of arrhythmia, other causes include smoking, alcohol, and caffeine intake. However, there had not been much research on the impact that diurnal ranges have on arrhythmia.

From 2008 to 2011, Professor Kim and his research team carried out an experiment exploring the correlation between arrhythmia and diurnal ranges. Collecting the data of 31,629 patients who visited the emergency room due to arrhythmia, the team found that with every 1°C increase in the diurnal range, the risk of arrhythmia also increased.

The research report was published in the recent issue of the International Journal of Biometeorology.

Statistics from the report show that with every 1°C increase in the diurnal range follows a 1.84% increase in the number of emergency room patients with arrhythmia.

For example, if the diurnal range on a certain day was 5°C and is increased to 6°C the next day, the probability of patients visiting the emergency room due to arrhythmia increases by 1.84%. If the diurnal range increased by 5°C from the previous day, the risk of arrhythmia becomes 9.2%.

Results from the experiment revealed that the probability of developing arrhythmia is greatest in spring with a correlation of 3.76%, then in autumn (1.18%), and least likely in winter (0.87%). Women are more susceptible to developing arrhythmia due to diurnal changes (3.84%) than men (1.57%). In terms of the population age group, those from ages 65 and above (3.13%) have the highest risk of developing arrhythmia than other age groups.

One of the best ways to prevent arrhythmia is to exercise daily for a minimum of 30 minutes to maintain reasonable weight and waist size. Cardio exercises such as walking, running, cycling, and swimming, as well as exercises that relax body muscle such as stretching and yoga are also useful prevention methods.

One should however, refrain from exercising or hiking in the morning or evening when the temperature is low. If this is not possible, it is important to warm up the body for ten minutes before exercising so that the heart can adjust to the cold climate. Another important factor is to start and finish the exercise routine at low intensities.

If you experience any chest pains or difficult breathing at any moment while exercising, seek medical help immediately.

Written by Hye Bin Lee, SNU English Editor, hahahybes@snu.ac.kr
Reviewed by Professor Travis Smith, Department of Asian Languages and Civilizations, tlsmith@snu.ac.kr