Alarm Clock Alerts Family to Genetic Heart Problem

ByABC News
April 5, 2006, 9:57 PM

April 6, 2006 — -- A ringing alarm clock marked the beginning of a medical mystery for the Shockley family.

It was August 1996, and Linda Shockley heard the alarm, but her daughter Casey, a 16-year-old lacrosse player, didn't get out of bed.

When she went to Casey's room, Linda realized something was wrong and called to her husband, Bill. "I think she said, 'Bill, she's not breathing,'" he said. "It was one of the most frightening sounds I've ever heard."

For 30 minutes, Bill and Linda, who are both doctors, administered CPR, frantically fighting unsuccessfully to save their daughter's life.

"As a mother, you just don't kiss your child goodnight and put her to bed, and for her to die and not know," Linda said. "I wanted to know why. What happened?"

How does a seemingly healthy, active teenager suddenly die? As doctors later discovered, a heart abnormality, one that could have been triggered by something as benign as an alarm clock, killed Casey.

And the same defect may be to blame for more than half the sudden, unexplained deaths in teenagers and young adults, killing as many as 4,000 young people a year.

Casey had never been seriously ill, though she had fainted a couple of times and once complained that she felt her heart racing. Taking no chances, Bill and Linda took her for some tests. The results came back normal.

Just a day before her death, Casey had an electrocardiogram and was given a clean bill of health.

Dr. G. Michael Vincent, a cardiologist at LDS Hospital in Salt Lake City and a pioneer in the study of sudden cardiac deaths, was able to uncover the mystery for the Shockleys. He looked at Casey's EKG from the day before she died and noticed something that many doctors might miss.

Casey's EKG showed a much longer interval between the Q and T waves than what is considered normal. The teenager had died of something called long QT syndrome, a primarily genetic glitch in the heart's electrical system that can trigger a fast, irregular and lethal heartbeat.

Unfortunately, it's something that doctors often miss.