Acute myocardial infarction after manual or automated snow removal

Abstract

Colder temperatures and major snowfalls are often followed by an increased number of cardiovascular events from ischemic heart disease, especially among men. 1 Heppell R Hawley S.K Channer K.S Snow shoveller’s infarction (letter). BMJ. 1991; 302: 469-470 Crossref PubMed Scopus (27) Google Scholar , 2 Glass R.I Zack M.M Increase in deaths from ischemic heart-disease after blizzards. Lancet. 1979; 1: 485-487 Abstract PubMed Scopus (86) Google Scholar , 3 Rogot E Padgett S.J Associations of coronary and stroke mortality with temperature and snowfall in the United States, 1962–1966. Am J Epidemiol. 1976; 103: 565-572 Crossref PubMed Scopus (137) Google Scholar , 4 Glass R.I Wiesenthal A.M Zack M.M Preston M Risk factors for myocardial infarction associated with the Chicago snowstorm of Jan 13–15, 1979. JAMA. 1981; 245: 164-165 Crossref PubMed Scopus (11) Google Scholar , 5 Faich G Rose R Blizzard morbidity and mortality Rhode Island, 1978. Am J Public Health. 1979; 69: 1050-1052 Crossref PubMed Scopus (42) Google Scholar , 6 Auliciems A Frost D Temperature and cardiovascular deaths in Montreal. Int J Biometeorol. 1989; 33: 151-156 Crossref PubMed Scopus (35) Google Scholar , 7 Baker-Blocker A Winter weather and cardiovascular mortality in Minneapolis-St. Paul. Am J Public Health. 1982; 72: 261-265 Crossref PubMed Scopus (90) Google Scholar , 8 Gorjanc M.L Flanders W.D VanDerslice J Hersh J Malilay J Effects of temperature and snowfall on mortality in Pennsylvania. Am J Epidemiol. 1999; 149: 1152-1160 Crossref PubMed Scopus (47) Google Scholar Considering the body’s normal thermoregulatory responses to cold, including increased platelet aggregability and plasma viscosity, 9 Keatinge W.R Coleshaw S.R Cotter F Increases in platelet and red cell counts, blood viscosity, and arterial pressure during mild surface cooling factors in mortality from coronary and cerebral thrombosis in winter. BMJ. 1984; 289: 1405-1408 Crossref PubMed Scopus (475) Google Scholar coronary spasm or vasoconstriction, 10 Kawahara J Sano H Fukuzaki H Saito K Hirouchi H Acute effects of exposure to cold on blood pressure, platelet function and sympathetic nervous activity in humans. Am J Hypertens. 1989; 2: 724-726 Crossref PubMed Scopus (108) Google Scholar the marked increases in heart rate and systolic blood pressure that can occur when clearing snow from sidewalks and driveways, 11 Franklin B.A Hogan P Bonzheim K Bakalyar D Terrien E Gordon S Timmis G.C Cardiac demands of heavy snow shoveling. JAMA. 1995; 273: 880-882 Crossref PubMed Scopus (53) Google Scholar as well as ischemia at a lower rate-pressure product, 12 Juneau M Johnstone M Dempsey E Waters D.D Exercise-induced myocardial ischemia in a cold environment. Effect of antianginal medications. Circulation. 1989; 79: 1015-1020 Crossref PubMed Scopus (44) Google Scholar it appears that a variety of pathophysiologic mechanisms for acute myocardial infarction (AMI) may be operative in this environment. On January 2, 1999, the greater metropolitan Detroit area experienced a major snowfall (28 cm), followed by an unusually large amount of heavy wet snow over the next 12 days (total 61 cm). Average temperature and windchill for this period were −10.2°C and −26.1°C, respectively.