Serious Dangers of Intense Activity at Work

Heart attacks and stroke may follow vigorous activity at work and prove fatal

(RxWiki News) In general, exercise boosts heart health. A job that demands rigorous physical activity, however, might trigger a heart attack or stroke, especially for those with high risk factors.

To maintain a healthy heart, the American Heart Association recommends getting at least 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise (or a mix of moderate and vigorous activity).

As beneficial as exercise may be, a new study has found that strenuous activity on the job may cause a fatal cardiac event, especially for those who show signs of potential heart problems, such as high cholesterol and high blood pressure.

"Be careful of strenuous activity’s effect on the heart."

Amna Zarar, MD, a researcher at Zeenat Qureshi Stroke Institute in St. Cloud, Minnesota, and colleagues examined details on 199 fatal cardiovascular events that firefighters had while on the job.

Dr. Zarar and team observed that almost three quarters of these firefighters died after an average of 33 minutes of vigorous activity, while about a quarter died following light to moderate activity.

Levels of activities (light, moderate, vigorous) were determined using the Metabolic Equivalent of Tasks (METs) method, which provides a measure of energy spent during different activities. For example, walking or light use of hand tools may be considered a light activity. Washing vehicles or windows may be a moderate activity.

A total of 88 firefighters had a cardiac event while engaged in the vigorous activity of fighting a fire, and at least 61 were responding to an emergency.

Just over a third of the cardiac events happened at the fire station, where fitness training or lifting heavy hoses or other equipment appeared to be the trigger.

The cardiac events included 167 heart attacks, 12 arrhythmias, nine sudden cardiac deaths, three strokes, two cardiac tamponades (pressure on the heart caused by fluid buildup) and two hypoxic brain injuries (a condition in which not enough oxygen reaches the brain).

Dr. Zarar and colleagues noted that most of those who died were not old. More than half the subjects were under the age of 50, with the average age being 49. They had worked an average of 22 years as firefighters.

In reviewing medical histories, the researchers discovered that cardiovascular risk factors may have contributed to these deaths. Among those who had been performing strenuous physical activity, 94 had high cholesterol, 93 had high blood pressure, 20 were smokers, seven had diabetes and 11 had family members with heart disease.

Among those who were performing light to moderate activity, 38 had high blood pressure, 34 had high cholesterol, 20 were smokers, seven had diabetes and 11 had family members with heart disease.

"Firefighting is a job that can be very physically and emotionally intense, but firefighters also typically have long stretches of downtime. By its nature, firefighting and other emergency work is unpredictable, but can require rapid and sustained bursts of energy at any time," Sarah Samaan, MD, cardiologist and physician partner at the Baylor Heart Hospital in Plano, Texas, told dailyRx News.

"Like many other Americans, it is not unusual for firefighters to suffer from heart disease and stroke risk factors such as high blood pressure, high cholesterol, obesity, and diabetes. Some may also be smokers, which is another major risk factor. However, most of us are not required to save lives and property under the most intensely stressful conditions," said Dr. Samaan.

"This study highlights the importance of screening our firefighters and other first responders for treatable and preventable risk factors, and for helping them to take action to achieve optimal health," she said. "Their lives, as well as ours, may be on the line."

Screening for high-risk cardiac factors could help reduce fatal events, according to Dr. Zarar. Tests should cover cholesterol levels, blood pressure, blood sugar (for diabetes) and electrocardiogram stress (to measure the heart’s electrical activity).

"People also need more awareness of the symptoms and signs that can precede or occur with a heart attack or stroke, along with better screening for risk factors with regular health check-ups,” Dr. Zarar said in a press release.

This study was released February 24 but will be presented at the American Academy of Neurology's 66th Annual Meeting in Philadelphia, April 26 to May 3, 2014. The study was supported by the Zeenat Qureshi Stroke Institute.

Review Date: 
February 24, 2014