A city official and other doctors are urging the public to call 911 when there’s a heart attack to make sure they’re routed to the appropriate hospital.

The recent closure of two hospitals on Oahu — Hawaii Medical Center East and West — has stretched emergency care, sometimes forcing medical officials to divert patients from facilities that are over capacity, said Don Weisman, director of the American Heart Association’s "Mission: Lifeline" in Hawaii.

"In medical emergencies, such as heart attack, it is important for the public to call 911 to be transported to a hospital that is capable of providing the optimum care to the patient," Weisman said. "It’s all about saving lives."

Weisman said in addition, emergency care technicians in ambulances are equipped with machines that can make preliminary diagnoses of heart attack patients and alert the appropriate hospital about the need for surgery, including procedures to reopen clogged arteries.

Cardiac surgeon Dr. William Dang Jr. said that with the help of emergency technicians in ambulances, the patient can receive a diagnosis while on the way to the hospital and be taken directly into surgery.

Dang said damage to the heart is minimized when surgery to open the clogged artery is done in a timely manner.

The medical procedure usually requires a balloon catheter to be put into the artery. The balloon is inflated, compressing the blockage and increasing the blood flow.

"The sooner we get it in there, the more heart tissue we save," he said.

About half of heart attack patients in Hawaii transport themselves to the hospital or are delivered by someone other than emergency medical technicians, according to the American Heart Association.

Dr. James Ireland, director of the city Emergency Medical Services Division, said using the ambulance for transport in emergencies avoids the potential of a vehicular crash, getting stuck in traffic and going to a hospital that might not be equipped to handle the emergency.

"We’re going to take patients to the closest available and appropriate facility for their care," he said.