Association of Level of Physical Exertion with Acute Myocardial Infarction in Bangladeshi Population

Association of Level of Physical Exertion with Acute Myocardial Infarction in Bangladeshi Population Md. Kamrul Azad1 , Abdul Wadud Chowdhury2, Mohammad Arifur Rahman3, Shohael M Arafat4, Sheikh Foyez Ahmed4, Sathi Dastider5 1250 Bedded TB Hospital, Shamoli, Dhaka, 2Department of Cardiology, Dhaka Medical College, 3Department of Cardiology, NICVD, Dhaka, 4Department of Cadiology, Bangabandhu Sheikh Mujib Medical University, Dhaka, 5Department of Maternal and Child Health, NIPSOM, Dhaka Abstract Key Words: Physical Exertion, Acute Myocardial Infarction. Background: Evidences suggest that heavy physical exertion can trigger the onset of acute myocardial infarction. But there have been no clean cut data in Bangladesh about the risk of myocardial infarction during and after heavy exertion. To address this question the study was conducted. Methods: It was a multicentre cross sectional study was conducted from July 2012 to June 2013 with patient of diagnosed acute myocardial infarction (AMI) admitted in department of cardiology of National Institute of Cardiovascular Diseases (NICVD), Bangabandhu Sheikh Mujib Medical University (BSMMU) and Dhaka Medical College Hospital (DMCH). From selected samples, two hours activity prior to onset of symptom of AMI was asked according to standard questionnaire. Activities were quantified on a scale from 1 to 8 metabolic equivalents (METs) according to generally accepted values. Collected data were analyzed by SPSS version 16. Results: In this study 246 patients (74 .4 percent of whom were men; mean age [±SD], 64.68 ± 7.63 years) were interviewed. The study showed that 11.38% patients were engaged in strenuous physical exertion (e” 6 METs) within two hours prior to symptom onset of AMI. Strenuous exertion group of AMI patients were all most all sedentary worker [26 (92.86%) of 28]. Most of the patients (82.14 %) of strenuous group had history of less than 8 hours work per day. Strenuous exertion group had history of longtime exertion (72.57%, 1-2 hours) than non-strenuous group (42.66%, <0.5 hours). Moreover, 67.86% AMI patients of strenuous exertion group had experienced irregular exertion whereas most of the patients (64.22%) of non strenuous group had a history of regular exertion. Conclusions: The result of the study indicates that a period of strenuous physical activity is associated with increased risk of having AMI, particularly among patients of sedentary worker who have dyslipidemia and who exercise irregularly. Those who exercise regularly have lower chances of AMI as shown by the negative correlation. (Cardiovasc. j. 2016; 8(2): 115-122) Introduction: An individual’s long-term risk of AMI is determined, at least in part, by ‘traditional’ chronic risk factors, such as lipid levels, long-term average blood pressure, smoking habits and novel risk factors associated with increased vascular inflammation, such as C-reactive protein.1 However, based on an individual’s risk, acute events may be precipitated or triggered by discrete transient exposures including physical, psychological, or chemical stresses.2 Quantitatively, the period of intense exercise and subsequent recovery is associated with about a 6fold higher myocardial infarction rate. One observed mechanism for this phenomenon is the increased arterial pulse pressure stretching and relaxing of arteries with each heart beat which, as has been observed by intravascular ultrasound, increases mechanical “shear stress” on atheromas and the likelihood of plaque rupture and ultimately occlusion by thrombus at area of coronary artery. Clarification of the role of physical exertion in triggering myocardial infarction is important for several reasons. It is estimated that more than 1.5 million myocardial infarctions occur annually in the United States, and at least 75,000 of these infarcts which lead to 25,000 deaths may occur soon after exertion.2,4 However the American Heart Association has recently recommended increased physical activity as an important way to reduce the risk of heart attack.5 Heavy physical exertion therefore appears to be a two-edged sword, both triggering and preventing myocardial infarction. Address of correspondence: Dr. Mohammad Arifur Rahman, Department of Cardiology, National Institute of Cardiovascular Diseases, Dhaka, Bangladesh. E-mail: Cardiovascular Journal Volume 8, No. 2, 2016 Despite evidences6 suggesting that heavy physical exertion can trigger the onset of acute myocardial infarction in different countries but there have been no clean cut data in Bangladesh of the risk of myocardial infarction during and after heavy exertion, the length of time between heavy exertion and the onset of symptoms (induction time), and whether the risk can be modified by regular physical exertion. To address these questions, the study was done. within 2 hours of physical exertion. Sample were selected from the population by non-probability sampling technique and were excluded those who were disagree to participate in the study and those who had severe co-morbidity. From selected samples, two hours activity prior to onset of symptom of AMI was asked according to standard questionnaire. Activity was quantified on a scale from1 to 8 metabolic equivalents (METs) according to generally accepted values. Methods: This multicentre cross sectional study was conducted in Department of Cardiology of National Institute of Cardiovascular Diseases (NICVD), Bangabandhu Sheikh Mujib Medical University (BSMMU) and Dhaka Medical College Hospital (DMCH) from July 2012 to June 2013 in order to get relative risk of acute myocardial infarction Level of physical exertion: The degree of physical exertion is quantified on a scale from1 to 8 metabolic equivalents (MET) according to generally accepted values.7 1 MET is defined as the energy expended per minute by a subject sitting quietly and is equivalent to3.5 ml of oxygen per kilogram of body weight per minute by a 70-kg adult.7,8 Estimated No. of MET Description Type of Activity 1 Sleeping, reclining Sunbathing, lying on a couch watching television 2 Sitting Eating, reading, desk work, sitting watching television, driving on the highway 3 Very light exertion Office work, driving in the city, personal care. standing in line, strolling in a park 4 Light exertion, with normal breathing Mapping, slow walking (e.g., shopping), bowling, sweeping, golfing with a cart, gardening with power tools 5 Moderate exertion, with deep breathing Normal walking, golfing on foot, slow biking, downhill skiing, calisthenics, raking leaves, cleaning windows, hanging wallpaper, interior painting, hunting, fishing, slow dancing, light restaurant work (e.g., waiting tables, serving drinks) 6 Vigorous exertion, with panting; overheating Slow jogging, speed-walking, tennis, swimming, cross-country skiing, shoveling snow, fast biking, mowing with a push mower, pruning trees or shrubs, heavy gardening, factory assembly work, heavy househo (...truncated)