What better time than February, a.k.a. American Heart Month, to take a refresher on surprising heart-attack triggers, and to review warning signs that, if caught early, can keep you and loved ones safe.

Snow Shoveling

This exercise-of-necessity winter springs upon us can be even more heart-strenuous than a treadmill session. That’s because many who suddenly find themselves shoveling out cars and driveways do not regularly exercise, making the sudden strain of heavy-snow-heaving so abrupt that it can potentially throw the ticker into a tailspin. When researchers from Canada’s Queen’s University analyzed, in a 2011 study, records of 500 patients whose heart troubles brought them to the hospital over two winters, 35 (or seven percent) had experienced the heart-attack symptoms while shoveling snow.

3 Researcher-Identified Risk Factors:

* Being male

* Family history of premature coronary artery disease

* Smoking

Cold weather is another risk factor—hiking blood pressure, making blood more readily clotted, and interrupting blood flow to the heart. Brush up on Heart Attack Symptoms here.

Safer Shoveling:

* Hydrate before, during, and afterarthritis and heart disease ad

* Stretch and warm up first

* Shovel for short periods, taking frequent breaks

* Shovel smaller amounts of snow

* If you have the means, hire a neighborhood teen

Broken Heart Syndrome

Also known as stress-induced cardiomyopathy, BHS can lead to serious, short-term heart-muscle failure, even in those otherwise healthy. This sudden, intense chest pain occurs in reaction to a deluge of stress hormones, reports the American Heart Association, and affects more women than men. Death of a loved one, a traumatic breakup, heartbreak, divorce, betrayal, or romantic rejection can all be culprits. Some symptoms overlap those of heart attack, but with BHS there’s no evidence of blocked arteries. Instead, the heart temporarily enlarges, thereby inhibiting pumping. Good news: BHS is treatable and recovery often occurs within weeks.

Symptoms:

* Chest pain

* Shortness of breath

* Irregular heartbeat

Sexual Activity

While one 2011 Journal of the American Medical Association study concluded that sexual activity almost triples heart-attack risk, this finding refers to relative risk, which, as Harvard Health points out, is not as crucial as absolute risk. According to a calculation by Massachusetts General cardiologist James Muller, MD, a  50-year-old man who exercises regularly has an absolute risk of heart attack of one-in-a-million per hour. Factor in sexual activity and you’re still talking a three-in-a-million-chance per hour. (Note: Heart-attack survivors are at higher risk). So while sex could potentially spur heart attacks, this is relatively rare. What’s key to lowering risks? Frequent exercise. You just knew we’d say that, didn’t you.

Which heart-attack trigger most surprises?