Mr. Schultz is a 64-year-old accountant with a past medical history of high blood pressure and high cholesterol. He has been a smoker for the past 35 years and despite his wife and his doctor “gently nagging” him about it and him trying to quit multiple times, he still has not been able to kick the habit. His work as an accountant keeps him mostly seated at a computer and, while he tried to walk a couple of days per week over the summer, it is winter now and the chilly weather has kept him inside and safely on the couch.
Mr. and Mrs. Schultz are very excited because for the first time in many years, all four of their children and their families will be coming to stay at their house for the Christmas season. The house has been cleaned and decorated but, unfortunately, a heavy snow has been blanketing the area for the last several hours and has delayed everyone’s arrival. Mr. Schultz had at first meant to clear the snow as it came down but then decided just to wait until it stopped so that he would only need to go out in the cold once. His wife had different ideas and, after several hours of “gentle nagging” he finally went out. He had insisted on eating a big meal of steak and potatoes and several cups of coffee before starting the job to “keep his strength up” while he worked. He opted for a sweatshirt instead of his winter jacket, hat, and scarf thinking that the effort of shoveling snow would soon warm him up. He used the bigger of his snow shovels and tried to load it as much as possible with the hope that this would make the work go faster.
The temperature was bitterly cold, and the driveway was large and at first, he moved slowly, making sure to take frequent smoke breaks. But, when his wife came out and told him the first of the kids would be arriving in less than 40 minutes, he knew that he needed to hurry or there would be no place for them to park. She offered to help and had even brought out a second shovel, but he worried about her bad back and so asked her to let him finish the driveway alone. He really started to push himself, loading the shovel even more and not stopping to rest even when he started to become short of breath.
As he worked he noticed some chest discomfort that felt like a heavy pressure and some lightheadedness, but dismissed them as signs of him being out of shape. He mentally promised to take time that night to look through the various gym membership offers he had received in the mail with special New Year’s promotional deals to get more fit.
He continued to try and push himself but his shortness of breath and the pressure in his chest was getting worse and now he was feeling nauseous and the pain and numbness in his left arm was radiating up into his jaw. He slumped down onto one the snow piles he created while shoveling hoping that a rest would relieve his symptoms, but they only continued to get worse. With great difficulty, he got up and stumbled back to his house where he collapsed just inside the door.
Shoveling snow is a known trigger for a heart attack and the story of Mr. Schultz, unfortunately, is not very uncommon. When snow begins to fall and accumulate, Emergency Departments, especially in the nation's snowbelt, begin to prepare to receive additional patients who ventured out to clear their driveways, vehicles, steps, and walkways.
In our discussion of snow shoveling and a heart attack, we will examine the pathophysiology of how these two events are connected, who is at greatest risk, signs and symptoms to watch for, and tips for preventing a heart attack before and during shoveling snow. Finally, we will examine four ways that Emergency Medical Services (EMS) can achieve higher survival rates for those who suffer a heart attack outside of the hospital setting.
How Shoveling Snow Can Lead to a Heart Attack
There are two major reasons that shoveling snow can lead to a heart attack: intense physical exertion and the effects of cold weather on the blood vessels. The first reason is an obvious one, but is not always appreciated to the extent that it should be. Shoveling snow can be more strenuous than running full speed on a treadmill and can easily involve lifting and then throwing nearly a ton of snow. This type of exercise can put increased strain on the heart though an elevation in both heart rate and blood pressure. Using a snow blower instead of a shovel to clear snow can put less stress on the heart, but for some people, that still might be too much.
The cold weather also adds to the risk of having a heart attack by causing the coronary arteries, the blood vessels that supply the heart, to contract. This contraction of the coronary arteries means that less blood will flow to the heart which will reduce the amount of oxygen that gets delivered. The decreased supply of oxygen to the heart combined with the greater demand for oxygen because of physical exertion, has the potential to lead to a heart attack.
Individuals at Risk
The individuals who are at greatest risk for suffering a heart attack while shoveling snow in cold weather include those with a history of:
- Previous heart attack
- Known heart disease
- High cholesterol
- High blood pressure
- A sedentary lifestyle
These people should talk with their doctors before attempting to shovel any amount of snow.
Heart Attack Signs and Symptoms
The signs and symptoms most commonly associated with a heart attack include the following:
- Pressure, tightness, pain, or an aching sensation in the chest or arms that may radiate to your back or jaw
- Nausea, abdominal pain, heartburn, or feelings of indigestion
- Shortness of breath or fatigue
- Cold sweat
- Lightheadedness or sudden dizziness
Not all people who suffer a cardiac arrest will have all of these symptoms and they can all present with varying degrees of severity. Some individuals can even lack any symptoms while for others the first sign may be sudden cardiac arrest, in which the heart abruptly stops beating. Heart disease is the leading cause of death for both men and women so always have a high index of suspicion for a heart attack.
Tips for Preventing a Heart Attack Before and After Shoveling Snow
Before shoveling snow:
- Talk to your doctor to determine if you have any medical issues that would make it dangerous for you to shovel snow
- Do not shovel snow when you first wake up in the morning as this is when more heart attacks occur due to the increased propensity of blood to form clots. It is recommended you wait at least 30 minutes before starting.
- Do not eat a heavy meal before you shovel snow. This causes blood to be diverted away from the heart and towards the stomach.
- Warm up before starting to shovel by walking for several minutes
- Avoid drinking coffee or smoking for one hour before/after shoveling snow. Both coffee and cigarettes are stimulants and elevate heart rate and blood pressure which can further increase your risk for a heart attack.
While shoveling snow:
- Use a small shovel to reduce the amount of snow that you need to lift and throw
- Start slow and take frequent breaks
- Drink plenty of water to prevent dehydration
- Avoid hypothermia or overheating by dressing in layers
- Keep your head and neck covered to preserve body heat
- Cover your mouth because breathing in cold air can trigger angina or breathing problems
- Watch for the warning signs of a heart attack and if you think you are having one, call 9-1-1 immediately
Ways to Achieve Higher Cardiac Arrest Survival Rates
In 2011 it was reported that of the 326,200 people who experienced cardiac arrest in a non-hospital setting in the United States for that year, those that were treated by Emergency Medical Services (EMS) had a survival rate of only 10.6%. These low survival rates have prompted the National Academy of Medicine to release a report in which they detailed multiple evidenced-based recommendations to improve these survival statistics. The four recommendations that have the highest potential reward in terms of improving cardiac arrest survival in any community are as follows:
- High performance CPR is defined as having minimally interrupted chest compressions with correct rate, depth, and chest wall release coordinated with ventilations given at the correct rate, timing, and tidal volume and synchronized with defibrillation attempts. The infographic below gives more details on the characteristics of high-performance CPR. This type of CPR has been shown to strongly impact survival outcomes, but it is not uniformly provided during resuscitation efforts.
9-1-1 Telecommuter CPR
- CPR performed by a bystander can more than double the chance of survival for someone who had suffered an out of hospital cardiac arrest. Unfortunately, bystander CPR is only given about 40% of the time in the United States. Training more members of the public to use CPR is an effective way to increase the number of lives saved, but another way is to train 9-1-1 dispatchers to coach people. When a call is placed, the trained dispatcher can identify a potential instance of cardiac arrest, calm the bystander, and then coach them to begin and continue CPR using standardized instructions.
System Measures and Quality Improvement
- Survival rates for out of hospital cardiac arrests can only be improved if EMS systems are recording their incidence and process of care. By examining how the processes that are in place lead to the outcomes observed, the strengths and weaknesses of the system can be recognized and plans to improve care can be formulated.
Medical Director Leadership
- EMS medical directors are uniquely situated to improve survival rates for out of hospital cardiac arrest in the communities they serve. They know the science behind resuscitation and its ability to save lives and yet, they also understand the issues and challenges that the system faces. They are in a unique position to enact change at multiple levels and can communicate with the leaders of other healthcare groups to enact broader and more sweeping changes.
Sources and More Information
Cleveland Clinic, “Snow Shoveling—A Real Risk for Heart Attack”
Harvard Health, “Protect your heart when shoveling snow”
Harvard Heath, “Avoiding winter heart attacks”
JEMS, ” Four Ways EMS Can Achieve Higher Cardiac Arrest Survival Rates”
Metro Health, “Shoveling and Your Risk for Heart Attack”
Jeremiah Johnson, MA, BS