Cardiovascular Hazards of Winter

The chill. Can it kill?
Baby, it’s cold outside. If you’re a New Englander, you can handle what Mother Nature throws your way – but did you know that winter poses a wide range of risks to your heart and blood vessels?
The good news is that most winter-related health problems can be prevented by taking common sense precautions.
The heart in winter
“We prefer to talk about the cold weather season, not just cold weather,” says Dr. Amjad AlMahameed, right, director of the Vascular Medicine Program of the CardioVascular Institute at Beth Israel Deaconess Medical Center. “Cold weather can lead to health issues, but there are other problems that might arise not from the cold itself but from our responses to the weather, such as when a sedentary person or a person with a heart condition goes out and shovels snow.”
Cardiovascular death rates are an average of 26 to 34 percent higher from January through March, according to a four-year study of 1.7 million death certificates in a variety of warm and cold U.S. locations. These included Massachusetts, Southern California, Texas, Arizona, Georgia, Washington and Pennsylvania. The causes of death were heart attack, heart failure, stroke and a general “cardiovascular disease” category.
Additional research revealed a 33 percent increase in coronary-related deaths during the months of December and January compared to the June-September period. The study focused on coronary deaths in Los Angeles County during a 12-year time period. The authors concluded that, “Although cooler temperatures may play a role, other factors such as overindulgence or the stress of the holidays might also contribute to excess deaths during these peak times.”
“These studies and others leave little doubt that death rates due to cardiovascular and other diseases are higher in winter than in summer,” says AlMahameed. “The question is why. Research has not nailed this down yet, although it has identified potential culprits.”
Beware the snow shovel
Perhaps the most notorious cold-weather cardiovascular risk is heart attack after shoveling snow. Research has shown that heavy activity increases the likelihood of a heart attack – sometimes called “snow-shoveler’s infarction” by researchers – shortly after the intense exertion. This is especially true for people with known existing cardiovascular disease and those with cardiovascular risk factors such as high blood pressure, high cholesterol or a sedentary life style who may have as yet undiagnosed (so-called subclinical) cardiovascular disease.
People who are outdoors in cold weather should avoid sudden exertion, like lifting heavy shovels full of snow. Even walking through heavy snow can strain the heart, according to the American Heart Association. Those with coronary artery disease may suffer chest pains (such as angina) simply by being out in cold weather.
“For people with known heart disease, those who have had heart attacks, stents or bypass surgery, cold weather makes the heart do extra work to generate the same amount of heat the body needs to function,” says AlMahameed. “It is like undergoing a stress test. They can suffer angina pains that can lead to a heart attack.”
Avoid the risks of snow shoveling:
•If you have a heart condition or have been sedentary for a long time, do not shovel snow. Consider using a snow blower or having someone help you.
•If you do shovel, use a small shovel so the load isn’t too heavy, work slowly and take frequent breaks.
•Don’t eat a heavy meal or drink alcoholic beverages before or immediately after shoveling.
•Be aware of the heart attack warning signs, including discomfort in the chest or other parts of the upper body, shortness of breath and nausea.
If you suspect you or someone else is having a heart attack, immediately call 911.
Fight flu and colds (with care)
Flu is caused by viruses, not cold weather. However, there is a higher incidence of heart attack during flu season, which typically starts in October and runs until mid-March. Having the flu can cause the heart to work harder to pump blood to the lungs. Inflammation may also cause plaques to rupture, blocking blood vessels and causing a heart attack. Plaques are deposits of a fatty, sticky substance found in the blood that may build up on artery walls.
That’s why it is so important to get an annual flu shot, AlMahameed says. This is especially true for people who already have cardiovascular disease or are getting older.
Colds, too, are caused by viruses and not cold temperatures. The issue here is that many over-the-counter cold medications can cause blood pressure to rise, whether you already have hypertension or not. This can be dangerous because high blood pressure is one of the risk factors for heart attack and stroke.
“Decongestants can interfere with blood pressure medications,” AlMahameed says. “In addition, some over-the-counter cold medications are high in sodium, which can also raise blood pressure. If blood pressure is an issue, consult with your doctor or a pharmacist before using cold medicines.”
Avoid the risks of flus and colds:
•Get a flu shot
•If you get the flu, see your doctor right away as an oral antiviral treatment may help reduce the duration of your illness
•Wash your hands frequently, especially before eating and after using the bathroom
•Avoid large crowds during the flu season
If you have high blood pressure, be aware of the decongestants and sodium in cold medications. More information
Keep warm
People who spend a lot of time outdoors in the extreme cold can suffer from hypothermia, in which the core body temperature falls below 95 degrees Fahrenheit. This can cause complete heart failure, organ damage, brain damage and even death.
“What happens is the overall blood flow to vital organs is compromised,” AlMahameed says. “The brain could potentially shut down. It can lead to mental confusion, damage to the nervous system, falls and sleepiness. If you fall asleep because you are hypothermic, you can freeze to death.”
Those most at risk for hypothermia, according to the American Heart Association, include the elderly, children, the mentally ill, people who already have heart disease, those who are out in the cold while intoxicated and anyone who is outside in frigid weather for prolonged periods of time. Many elderly people do not feel the cold and can therefore experience hypothermia without being aware of a problem.
Signs of mild-to-moderate hypothermia include shivering, mental confusion, stumbling and blue lips. Extreme hypothermia can trigger amnesia, faltering heart rate and other physiological signs and bizarre behavior, including “paradoxical undressing,” in which the person feels warm despite the heat loss and throws off his or her clothes.
Avoid the risk of hypothermia:
•Stay indoors in frigid weather.
•Keep warm by layering clothing. The layers trap warm air, providing protective insulation.
•Wear a hat to prevent heat from escaping through the head.
•Do not drink alcohol outdoors or before going outdoors in very cold weather.
Raynaud’s Phenomenon
Raynaud’s Phenomenon is a vascular condition in which blood flow is sharply reduced in response to cold or emotional stress. People who live in colder climates are more likely to get it, as well as women, people over 30 and those with a family history.
“Cold leads to the narrowing of blood vessels, particularly the small ones in the hands, toes, face nose and ears,” says AlMahameed. “When they are narrowed, the body wants to shunt blood away from the skin to the internal organs so they can continue their vital functions. Therefore, your skin loses heat. The skin of the affected area, typically the fingers or toes, turns colors to reflect the extent of blood flow. First it becomes pale or whitish, then blue, and eventually pinkish discoloration is seen. Raynaud’s Phenomenon can be very painful.”
The episodes — reversible blood vessel spasms — are usually brief and come and go. They leave no lasting harm in most cases. A rarer form, called Secondary Raynaud’s Phenomenon, can result in ulcers and tissue death (gangrene) and is linked to connective tissue disease. It can be treated with a variety of medications such as calcium channel blockers. Researchers are studying techniques to better diagnose and understand Raynaud’s and are evaluating new treatments to improve blood flow for those who suffer from the condition.
The cause of Raynaud’s is unknown. However, those who already have it can lessen its effects:
•Avoid exposure to cold, stress and certain medications
•Wear warm clothing when outdoors in winter weather with special attention to hands and feet
•Always wear shoes
•When an attack occurs, resort to a warm environment, and soak your hands in warm water
•If you have Secondary Raynaud’s, seek treatment for the underlying disease
Let it snow …
While it’s true that we can’t control the weather, we can control our response to it. Be cautious in extremely cold weather, especially during unusual exertions like snow shoveling. Boost your overall health with a healthy diet, regular exercise and an annual flu shot. Then, when the weather outside is frightful, let it snow, let it snow, let it snow!