The Relationship between Weather Temperature and the Incidence of Myocardial Infarction - Essay Example

The Relationship between weather temperature and the incidence of myocardial infarction (MI) in people aged 65 and older Coronary heart disease, more specifically, myocardial infarctions (MI) are reportedly more common among the elderly (individuals 65 and over) during the colder temperatures of winter. In fact, the leading cause of death in the elderly is heart disease: “At least 60% of all acute myocardial infarction cases occur in patients age 65 and older, and about one-third in patients older than 75”(Maheshwari, 2000). Essentially, during colder temperatures, the human body primarily seeks to maintain homeostatic conditions and therefore seeks to conserve body heat. One of the physiological responses to cold, external environments is vasoconstriction. When this takes place, particularly in the elderly, myocardial infarction is a likely event. The purpose of this research paper is to discuss how variations in weather temperatures may be related to the occurrence of myocardial infarctions in individuals over 65. This paper will also seek to identify risk factors and identify the biological mechanisms involved in myocardial infarctions as pertaining to the elderly. Numerous studies have indicated the event of myocardial infarctions in the elderly during colder temperatures based on mortality rates of individuals: “Seasonality in coronary heart disease (CHD) events, with a winter peak and summer nadir, has been recognized for many decades and across diverse populations” (Gerber, Jacobsen, Killian, Weston, & Roger, 2006). In a study conducted between 1979 and 2002, “2,066 SCD (48% women) and 2,676 incident MI (43% women) were recorded in Olmsted County. The mean age (SD) was 78 (13) years at SCD and 68 (14) years at incident MI (p < 0.001”( Gerber, Jacobsen, Killian, Weston, & Roger, 2006). Based on the findings of this particular study, it is fair to say that incidence of sudden cardiac death (SCD) increase during periods of colder temperatures, within the elderly community. The study also concluded that in cases of myocardial infarctions, no relationship to decreased weather conditions existed. However, it should be noted that this was a study conducted within one particular county in Minnesota, and therefore the findings can only be applied to that county. Other regions, with colder temperatures and larger populations may indicate a definitive risk for myocardial infarction among the elderly, in the months of winter. As early as 1938, scientists were noting incidence of myocardial infarctions occurring more prominently during times of colder weather conditions. What has been difficult to assess, however, is precisely the relationship between specific cardiac events, such as myocardial infarction, and specific weather temperatures: ”While the influence of seasonal variations on the incidence of myocardial infarctions has been extensively documented, the impact of individual meteorological parameters on the disease has so far not been investigated systematically”( Georre et al., 2007). In a study conducted by Georre, it was concluded that certain weather variables such as ambient pressure and pressure gradient occurred with elevated reports of myocardial infarctions. This data pertained to individuals living in Switzerland from 1991 - 1994. However, overall the study proved to be inconclusive in determining a direct relationship between specific coronary events and weather conditions. In accordance with standard nursing practice, it is critical for nurses to educate their patients as to the risk factors of poor cardiac health. Particularly, certain activities or high risk behavior that can cause or lead to myocardial infarctions as well as other cardiac issues. It is imperative for nurses to educate the public, as well as existing patients, as to the signs and symptoms of cardiac distress such as myocardial infarctions. Nurses should make sure that patients are aware that symptoms such as vomiting, sweating, weakness, chest pain (localized or non localized) and shortness of breath; can be indicative of myocardial infarction or other cardiovascular distress. These symptoms can indicate myocardial infarction but in many cases, MI presents with a myriad of atypical symptoms. This is why prevention is so crucial and should be stressed to the public as well as to patients. Elderly individuals have a higher propensity for myocardial infarctions. One of the reasons for this is that as one increases in age, one’s activity level usually decreases. This leads to poor cardiac health. In addition, as one ages, endothelial functions change, smooth muscle activity decreases, and circulation often worsens. As mentioned earlier, the body seeks to maintain body warmth as part of maintaining homeostatic conditions. When it is exposed to lower temperatures, the body will undergo a specific type of vasoconstriction called CIVC (cold induced vasoconstriction) which allows the body to conserve heat: “ CIVC lowers the temperature gradient between the skin and environment, decreasing heat loss and helping to maintain core temperature.”((Edwards, Gauthier, Hayman, Lang, & Kenefick, 2005). When CIVC takes place, the arteries will stiffen which will result in elevated systolic blood pressure. What also takes place is that when pressure waves travel through arteries, they will sometimes arrive prematurely in systole due to arteriole stiffening. This increases the outgoing cardiac pressure and therefore increases systolic blood pressure. This is specifically what takes place during the human body’s exposure to cold temperatures. Even more susceptible to such drastic cardiovascular changes are the elderly, who more than likely already have weakened cardiovascular conditions. The oxygen demand of the heart is also increased when individuals are exposed to cold temperatures. This will essentially create a greater demand on the heart with less oxygen presence. The ventricular walls are also placed under stress as this takes place: “Several biological mechanisms may be involved in the association between cold weather and sudden cardiac death (SCD). Low temperature has a hazardous effect on blood pressure, and may alter the ratio of myocardial oxygen supply to demand, increase ventricular wall stress, cardiac work and oxygen requirements, and reduce mechanical efficiency and coronary blood flow” (Gerber et al., 2006). All of these factors can account for the occurrence of cardiac events such as myocardial infarctions, certainly in the elderly. Based on the research of David G. Edwards and his team, systolic pressure was noted to increase in subjects exposed to cold temperatures. Changes in central pressure of subjects, however, did not take place in such cold conditions. Ultimately, it can be said that based on this particular study, vasoconstriction and increased wave reflection can be considered a function of low external temperatures. This contributes to both cardiac events such as myocardial infarctions as well as death. Based on research conducted by Marco Morabito and his team, it was discovered with every 10 degree Celsius decrease in temperature, the occurrence of cardiac events increased by 19 percent in individuals over 65 This exhibited a need for weather warnings particularly for the elderly population of Florence, Italy (where the study was conducted). The team also found that higher temperatures, though uncomfortable, showed a much lower occurrence of myocardial infarctions and other cardiac events. According to the research of O. Biedrzycki and an assembled team of pathologists, there is a direct link between incidence of myocardial infarction and the winter months in London. This study observed specific cardiac events in mortality cases, particularly the event of myocardial infarction. It was concluded that the cases of myocardial infarction increased as the outside temperature dropped. In addition, if can be noted that the elderly are prone to coronary heart disease and other factors which make them more vulnerable to cardiac events. Through the research of S. Goerre and team, it can be deduced that certain weather conditions such as ambient pressure and wind activities increased the occasion of myocardial infarctions in Switzerland from 1990-1994. These findings were more specific to wind and high pressure conditions as opposed to rain or snow. The findings for both rain and snow proved to be inconclusive. The research of Gerber’s team was indicitaive of specific biological mechanisms that take place during exposure to cold temperatures. These mechanisms include CIVC (cold induced vasoconstriction), raised systolic blood pressure, and ventricular wall stress. All of these mechanisms can lead to cardiac events including myocardial infarctioan and even death. The role of nurses in addressing coronary heart disease is both to educate and help prevent. It is essential to provide the public as well as patients with the information pertinent to avoiding cardiac events. It is evident through the research of this paper, that cold temperatures do in fact have an adverse affect on the elderly. Low temperatures also put individuals aver 65 at risk for myocardial infarctions in specific. Nurses must inform individuals of the importance of maintaing a warm environment at home as well as avoiding venturing outside when temperatures are low. Other critical information that nurses must provide is the maintaining of a healthy lifestyle in order to reduce one’s risk of cardiac events. This includes a diet high in fiber and low in fat and cholesterol. This also includes moderate daily activity as well as the avoidance of alcohol, tobacco, caffeine, and stress. It is the nurse’s responsibility to provide this information to not only the public (before they become patients) but also to existing patients. Nurses must also educate elderly patients in particular of dressing appropriately for weather conditions. If an individual must be outside temporarily, in cold temperatures, they should be informed of maintaining core temperature with the use of layers of warm clothing. In some cases, elderly individuals will have caretakers or family members that will require this information as well. If the elderly person is living with someone or being cared for by someone, that individual must be educated in responsibly dressing their elder. In conclusion, it is clear through the research conducted for this paper that colder temperatures have a direct and adverse affect upon the elderly. It is evident that specifically higher wind factors and pressure conditions directly affect the cardiovascular system. This is particularly harmful in the elderly as it can result in cardiac events such as myocardial infarctions and even death. It is also crucial for nurses to act as the educators and informants. Nurses are responsible for providing the details of a healthy lifestyle as the best prevention. In addition, nurses must act as the liason for the patient and educate caretakers and family members as to how to ensure that their elder remains warm and healthy during the Winter months. References: Biedrzycki, O, Baithun, S (2006) Seasonal variation in mortality from myocardial infarction and haemopericardium. A postmortem study. Journal of Clinical Pathology; 59:64-66; doi:10.1136/jcp.2005.025965 Edwards, David G., Gauthier, Amie L., Hayman, Melissa A., Lang, Jesse T. Kenefick, Robert W., first published October 13, 2005, Acute Affects of Cold Exposure on Central Aortic Wave Reflection, Journal of Applied Physiology 100:1210-1214 Hoy, E. H., & Panayi, G. S. (2001). Cytokine pathways and joint inflammation in rheumatoid arthritis. N Engl J Med, 344, 907-916. o INTERNET SOURCE (APA, 2001, p. 268+, examples p. 271+) Vioxx Removed From Market. Retrieved from American College of Rheumatology website on October4, 2004. http://www.rheumatology.org Maheshwari, A, Laird-Flick HS, Cannon, L.A., Dehart, D, 2000, Acute MI, Age Related Presentations and Treatment Options, Geriatrics 2000 Feb, vol. 55 (2), pp. 32 - 40, 37-40 Morabito, Marco, Modesti, Pietro, Amadeo, Cecchi, Lorenzo, Crisci, Alfanso, Orlandini, Simone, Maracchi, Giampiero, Gensini, Gian Franco, first published June 22, 2005, Relationships Between Weather and Myocardial Infarction: A Biometeorological Approach, The International Journal of Cardiology vol. 105 issue 3 pages 288-293 Yariv Gerber, PhD*,{dagger}, Steven J. Jacobsen, MD, PhD{dagger}, Jill M. Killian, BS{dagger}, Susan A. Weston, MS{dagger} and Véronique L. Roger, MD, MPH. (2006) Seasonality and Daily Weather Conditions in Relation to Myocardial Infarction and Sudden Cardiac Death in Olmsted County, Minnesota, 1979 to 2002. J Am Coll Cardiol, 48:287-292, doi:10.1016/j.jacc.2006.02.065 (Published online 22 June 2006). Read More