Jeremy Vallimont was 17 when he experienced his first heart problem.

"I never knew I had anything until I joined my high school swim team," Vallimont (senior-biology) said.

After swimming for hours at a pool for practice one day, he said, he noticed his heart was beating very fast and would not slow down -- a condition he later learned to be tachycardia.

Later that day, Vallimont told his parents of the situation. At first, they thought it was only asthma -- a mistake that, they later realized, could have cost him his life.

Fortunately, they decided to be on the safe side and took him to be tested.

"People with heart symptoms know to get checked out," said John Boehmer, associate professor of medicine at the Penn State College of Medicine.

On Saturday morning, Vice President Dick Cheney was taken to the George Washington University Hospital in Washington, D.C., after experiencing shortness of breath. After three hours of tests, no evidence of heart problems was found -- he has nothing more than a cold, according to The Associated Press.

"Cheney had a history of heart problems, so everyone took it seriously," Boehmer said.

Also Saturday, rapper Ol' Dirty Bastard, also known as Russell Jones, complained of chest pains in a Manhattan recording studio shortly before collapsing. Before the ambulance arrived, he died, just two days before his 36th birthday. Though chest pains sometimes indicate a heart attack, tests are pending to determine the cause of his death.

A heart attack occurs when blood flow to the heart suddenly stops, Boehmer said. It can lead to permanent heart damage or even death if no help is received.

Despite the risks, people with heart disease can still live normal lives.

Cheney, 63, has had four heart attacks since age 37 -- the latest in November 2000 -- and many visits to the hospital. He received an implantable cardioverter-defibrillator in summer 2001.

The under-the-skin implant, what Cheney calls his "pacemaker plus," monitors heart rate and delivers an electric shock when it detects cardiac arrest, Boehmer said.

Vallimont, who swam for Moon Area High School near Pittsburgh, had to endure many trips to the doctor's office and a variety of tests. He was told to carry a heart monitor to constantly record his heartbeat.

"It was extremely nerve-racking to know that he could pass out at any minute," said his mother, Ann Vallimont.

Vallimont was soon diagnosed with Wolff-Parkinson-White syndrome (WPW).

WPW is a genetic condition of the heart in which an extra electrical pathway between the upper and lower chambers to control heartbeat exists, Boehmer said. It can be cured using ablation, a technique using radio frequency and microwaves to destroy specific tissue to form an insulating scar, he said.

Vallimont underwent the five-hour operation during his senior year as his family waited in concern.

"It was very scary," his mother said, "but short-lived."

The operation was a success, but Vallimont was told he could never swim again. With the state championships around the corner, he persisted in persuading the doctors to allow him to compete under close supervision from the diving coach, his father. His doctors reluctantly agreed.

"I was very happy about being able to swim again," he said.

The Moon Area High School Tigers proceeded to win second place in the 2001 championships, and Vallimont himself earned a gold medal doing the butterfly in the 400-meter medley relay.