Don't be a hero when shovelling driveway, cardiologist warns
That snow-filled driveway of yours can be a killer, particularly if you're a man over 55. A 2017 study of more than 200,000 heart attacks and cardiac deaths in Quebec published in the Canadian Medical Association Journal found a 15 per cent higher risk of heart attack requiring hospitalization and a 30 per cent increase in deaths after a snowfall of 20 centimetres or more. And those risks jumped even higher when the snow was deeper and the storm lasted longer.
We asked Dr. Hassan Mir, a cardiologist at the University of Ottawa Heart Institute, what makes shovelling so hazardous and what you can do to stay safe.
Q: Is there something specific about shovelling that is risky?
A: There are patient-related factors and activity-related factors to be mindful of.
Over the age of 55, especially among men, there is significant risk of heart attack, death or hospitalization. That 55 is a bit of a magic number because it was what was used in the CMAJ study. But that's not to say that someone who is 50 is completely safe to go out and shovel snow, because if you have lots and lots of risk factors — if you have high cholesterol, high blood pressure, if you have diabetes, if you're a smoker, etc. — those things put you at risk of developing heart disease. And usually a heart attack happens either due to an emotional stressor or a physical stressor in patients that already have underlying risk factors like the ones I've mentioned.
If you're a 50- or a 55-year-old who's extremely fit and runs marathons, you're obviously not as at much risk as someone who's 50 and sedentary. But the reality is that most people that age, and particularly in the winter, are not fit.
Q: What about the activity itself? Is there something different about snow shovelling that makes it more hazardous than going for a run or cross-country skiing?
A: If you're shovelling snow, it's winter and it's cold outside. Patients I see with angina will tell you that even cold air can bring on an attack of angina.
Your arteries constrict and that typically drives your blood pressure higher and your heart rate higher. By constricting your arteries, it reduces the blood flow to your heart. If you add lifting, it increases the demand on your heart which means your heart needs more blood. There's some evidence that even two minutes of shovelling snow can be the equivalent of you hitting your maximum heart rate.
That's the mismatch. It's very different than just going out for a walk.
Q: Does the fact you're lifting something up over your head have an effect?
A: Yes. It's like weightlifting. When you're weightlifting, your blood pressure can shoot up into the 300s for a short period of time. That mechanism, that grunting, it's called the Valsalva manoeuvre, and that in itself can reduce blood flow to the heart.
Q: What advice do you have?
A: It ranges from some basic things like, “Don't do it. Especially if you're over 55 and a man.” But if you have no option, it's important to dress warmly, to take breaks. To stay hydrated. And you want to make sure you're warming up a little bit before you're going outside. You
don't want to just show up and start lifting. That's not just from a cardiac -arrest perspective, but to avoid pulling muscle.
And if you have to do it, ideally, you're not lifting. You're pushing it to the side. That will significantly reduce the amount of workload because you're not lifting against gravity.
It's good to get help, so it's not just one person going out. Get your family out or your neighbours or spend $10 and get a kid from the neighbourhood to help you out.
It's also really important to make sure that you recognize symptoms: chest pressure, discomfort, shortness of breath, palpitations, dizziness or light-headedness, because those can be signs of a heart attack. Those are the symptoms that are giving you the heads up that you need to call 911 and get medical attention immediately.
Q: Are there other factors at play in a blizzard like we had today?
A: In a storm like this, it means recognizing that ambulances aren't as available. It'll be tough to get to you in any case and that hospital resources are stretched in the middle of a pandemic. Sometimes it's helpful to just let things settle a bit and do it slowly. This is not the time to be a hero and shovel a heavy amount of snow.