The sudden death of Baltimore County Executive Kevin Kamenetz from cardiac arrest early Thursday underscores the need for anyone experiencing discomfort that could be related to a heart attack to quickly seek emergency medical care, experts said.

“Time is critical,” said Dr. Michael Millin, associate professor of emergency medicine at Johns Hopkins University. The first step for anyone experiencing symptoms of a heart attack — including chest pain, shortness of breath and fatigue — should be to call 911, he said.

Kamenetz, 60, a veteran politician who was running for Maryland governor, woke up not feeling well and traveled by car with his wife to a volunteer fire station that was two miles from his home. He spoke to a 911 operator from the parking lot, officials said, and the call woke medics inside the fire station. They came out to treat him, but his condition quickly deteriorated, and the medics — who tried CPR and an electronic defibrillator — could not revive him. Kamenetz was taken to University of Maryland St. Joseph Medical Center in an advanced life support ambulance and pronounced dead at 3:22 a.m.

Gail Cunningham, chief medical officer at University of Maryland St. Joseph Medical Center in Towson, said Kamenetz was experiencing ventricular fibrillation — the most serious cardiac rhythm disturbance.

Elise Armacost, public affairs director for the county fire and emergency medical services department, said the department has “no way of knowing” why Kamenetz drove to the fire station instead of calling 911.

That treatment for a heart attack — including chest compressions and defibrillation — should ideally begin four to eight minutes after the onset of symptoms, said Millin, medical director for Prince George’s County Fire/EMS.

No one should ever “second-guess” themselves if they think they are experiencing the symptoms of a heart attack, he added. Those symptoms can also include neck, jaw, back or abdominal pain, said Dr. Mary Norine Walsh, former president of the American College of Cardiology.

“Any symptom that comes on suddenly and acutely needs to be investigated promptly,” Walsh said. Often, a delay in calling 911 is the result of people not realizing their symptoms could indicate a heart attack, she said.

“Everyone who is reading this should learn CPR,” Walsh added. “The more people who know CPR and know how to do it well, the more lives can be saved.”

Cunningham said she did not know whether it would have made a difference if Kamenetz called 911 from his home, instead of driving to the fire station.

“Obviously with these conditions, time is everything,” she said at a news conference Thursday morning. “But I don’t know for how long he was suffering at home with chest pains or symptoms before he chose to do that. We obviously always really strongly urge people with symptoms like this to call 911 to activate emergency care as quickly as possible.”