Recent research has suggested a transient increase in the incidence of acute myocardial infarction after daylight saving time transitions (Citation1–4). A new Finish study supported the association of time transitions with change in temporal distribution of infarction onsets and suggested that pathological conditions such as diabetes mellitus and renal failure may modify the cardiovascular risk in the post-transitional period (Citation5). Particularly intriguing was the finding of a lower number of patients with previously verified ventricular arrhythmias among those having a myocardial infarction after the spring transition.
Daylight saving time transitions may induce smooth but potentially adverse behavioural changes. To be specific, spring time transition may have a disruptive effect on the rest-activity cycle of short-sleepers or evening type persons (Citation6,Citation7), while even moderate changes in timing of the sleep–wake cycle may affect mood (Citation8). An observation of a lower frequency of myocardial infarction triggered by physical exertion in days after the spring transition (Citation2) supports the hypothesis that subtle change in routine behaviour could alter some risk tendencies. For example, a state of low-level well-being and bad mood could induce some people to avoid their usual activities, especially if they associate such activities with symptoms of a known cardiac disease. Physical activity is a typical sympathetic trigger of acute cardiovascular events (Citation9). Even mild to moderate activities, such as slow walking or shopping, may provide sufficient sympathetic arousal to trigger ventricular arrhythmias (Citation10–13). It may be hypothesized that reduced physical activity in patients with known ventricular arrhythmia and other symptoms may lower their risk of myocardial infarction after the daylight saving time transitions. Conversely, by affecting the entire population, subtle emotional distress as a superimposed stressor may reveal coronary disease by triggering myocardial infarction in those without premonitory symptoms or known cardiac disease.
In future research, a more thorough insight into the plurality of determinants in the phenomenon of increased cardiovascular risk after the daylight saving time transitions may be provided by collecting data on chronotype and behavioural changes in those who suffered cardiac incident during this period. Further refinements of individual risk according to age, gender, genotype, cardiovascular and psychotropic medication taken, emotional disorders, and specific personality types should also be taken into account. As the increase in incidence attributable to time transitions may be as much as 1 in 100 myocardial infarctions per year (Citation2), this may not be considered insignificant from a public health perspective.
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The author reports no conflicts of interest. The author alone is responsible for the content and writing of this article.
References
- Kirchberger I, Wolf K, Heier M, Kuch B, von Scheidt W, Peters A, et al. Are daylight saving time transitions associated with changes in myocardial infarction incidence? Results from the German MONICA/KORA Myocardial Infarction Registry. BMC Public Health. 2015;15:778.
- Čulić V. Daylight saving time transitions and acute myocardial infarction. Chronobiol Int. 2013;30:662–8.
- Jiddou MR, Pica M, Boura J, Qu L, Franklin BA. Incidence of myocardial infarction with shifts to and from daylight savings time. Am J Cardiol. 2013;111:631–5.
- Janszky I, Ljung R. Shifts to and from daylight saving time and incidence of myocardial infarction. N Engl J Med. 2008;359:1966–8.
- Sipilä J, Rautava P, Kytö V. Association of daylight saving time transitions with incidence and in-hospital mortality of myocardial infarction in Finland. Ann Med. 2016;48:10–16.
- Lahti TA, Leppämäki S, Lönnqvist J, Partonen T. Transitions into and out of daylight saving time compromise sleep and the rest-activity cycles. BMC Physiol. 2008;8:3.
- Lahti TA, Leppämäki S, Ojanen SM, Haukka J, Tuulio-Henriksson A, Lönnqvist J, Partonen T. Transition into daylight saving time influences the fragmentation of the rest-activity cycle. J Circadian Rhythms. 2006;4:1.
- Boivin DB, Czeisler CA, Dijk DJ, Duffy JF, Folkard S, Minors DS, et al. Complex interaction of the sleep-wake cycle and circadian phase modulates mood in healthy subjects. Arch Gen Psychiatry. 1997;54:145–52.
- Čulić V. Acute risk factors for myocardial infarction. Int J Cardiol. 2007;117:260–9.
- Čulić V, Eterović D, Mirić D, Giunio L, Lukin A, Fabijanić D. Triggering of ventricular tachycardia by meteorologic and emotional stress: protective effect of ß-blockers and anxiolytics in men and elderly. Am J Epidemiol. 2004;160:1047–58.
- Čulić V, Silić N, Mirić D. Triggering of ventricular ectopic beats by emotional, physical and meteorologic stress: role of age, sex, medications, and chronic risk factors. Croat Med J. 2005;46:894–906.
- Fries R, Konig J, Schafers HJ, Bohm M. Triggering effect of physical and mental stress on spontaneous ventricular tachyarrhythmias in patients with implantable cardioverter-defibrillators. Clin Cardiol. 2002;25:474–8.
- Lampert R, Joska T, Burg MM, Batsford WP, McPherson CA, Jain D. Emotional and physical precipitants of ventricular arrhythmia. Circulation. 2002;106: 1800–5.