When the ambient temperature in nature drops from 17°C to below 0°C, the daily mortality rate from myocardial infarction per million population increases from 4.9 to 6.9. Reports in our country also indicate that the incidence of myocardial infarction is higher during the cold winter months, particularly from December to February. Especially during continuous low temperatures, overcast and rainy weather, and strong winds, the incidence of acute myocardial infarction significantly increases.
Myocardial infarction is a severe clinical manifestation of coronary heart disease, mainly caused by thrombosis within the coronary arteries and persistent coronary artery spasms. Why is myocardial infarction more common in winter? In the depths of winter, the stimulation of cold on the body increases the excitability of the sympathetic nervous system and increases the secretion of catecholamines. The latter can cause peripheral vasoconstriction, increased heart rate, and an increased workload and oxygen consumption for the heart. At this time, the myocardium can become ischemic and hypoxic, leading to the onset of angina pectoris. The excitation of the sympathetic nervous system and catecholamines themselves can also lead to coronary artery spasms. When rectal temperature drops to 30°C, it can cause plasma loss, decreased blood volume, increased platelet aggregation, and increased blood viscosity, leading to blood concentration and thrombus formation. This is also an important cause of myocardial infarction.
In the cold winter, people's physical activity decreases. It is also the season for nourishing the body, so people tend to eat more and move less, which raises blood lipid levels and increases blood viscosity. The busy pace of the Spring Festival and New Year's Day can lead to excessive fatigue, which can easily trigger a myocardial infarction. When the room temperature drops below 10°C, people may feel listless, down, and prone to sulking, which can induce angina pectoris, and in severe cases, myocardial infarction.
In view of this, as winter approaches, people with cardiovascular diseases, especially those with coronary heart disease, should pay close attention to weather forecasts,合理安排工作与休息的时间 (reasonably arrange their work and rest schedules), and adhere to their medication, such as low-dose aspirin or dipyridamole. The World Health Organization recommends that the indoor temperature in winter should not be lower than 18°C, and it should be 2-3°C higher for the elderly and patients with coronary heart disease. When a cold wave strikes, it is important to promptly add hats, clothing, and quilts and reduce going outdoors. In terms of diet, one should appropriately control the intake of salt and fat, eat more fresh vegetables and fruits, and avoid excessive fatigue and emotional excitement. People over 40 years old, with a family history of coronary heart disease, hypertension, hyperlipidemia, and other risk factors, should pay even more attention to cold prevention and warmth during the cold winter months to avoid future complications.