Strong link between shovelling snow, heart attacks: Study
By QMI Agency

KINGSTON, Ont. — It's a common sight in the winter — Canadians with mittens, boots and shovels digging out from under a snowstorm.

A new study has shown that, if you are in a particular high-risk group, this is an activity that can kill you.

Researchers at Queen's University and Kingston General Hospital have confirmed what only anecdotal evidence has previously suggested: Snow shovelling really can lead to heart attacks.

Dr. Adrian Baranchuk, a professor with the Queen's School of Medicine and a cardiologist at KGH, said the idea for the study began on a Saturday morning about three winters ago when he noticed something odd while doing rounds in the coronary care unit.

"Over 14 people had a heart attack associated with snow shovelling," he recalled. "This is something that motivates research."

The researchers reviewed two consecutive winters, 2008-09 and 2009-10, and plotted the duration of the winter and when it snowed. They noted the admissions to KGH with heart attacks within that time and divided them into shovelling and non-shovelling groups.

Of the 500 patients who came in with heart problems, 35 had experienced symptoms while out shovelling.

They found it was mainly men who were doing the snow shovelling and suffered subsequent heart attacks. The vast majority of women who had heart attacks hadn't done any snow shovelling.

They found two main risk factors — simply being a male gives you a five-fold bigger chance of having an acute coronary syndrome while shovelling, and if you have a family history of coronary artery disease, you are also at greater risk.

Smoking also placed a male at higher risk, the researchers found, and older males seemed more susceptible than younger ones.

Baranchuk said the time of day is also a factor.

"Usually this is done early in the morning because you need to take your car, and it is well demonstrated that heart attacks do happen early in the morning," he said.

The pace of snow shovelling is another contributing factor. Long periods of hard work followed by a brief period of time to catch your breath is the typical way someone shovels out their driveway.