>>> AND NOW TO A WAKE-UP CALL OF

A DIFFERENT KIND.

IT WAS AN APPLE WATCH ALARM FROM

A WOMAN IN MANHATTAN WHO SAYS IT

CHANGED THE ENTIRE DIRECTION OF

HER LIFE.

JESSICA MALONE HAD JUST BIKED

HOME FROM HARLEM TO HELL'S

KITCHEN WHEN THEY ARE APPLE

WATCH STARTED BUZZING.

>> AND THAT'S WHEN IT TURNED RED

AND VIBRATED AND WAS SAYING SEEK

MEDICAL ATTENTION.

AND THAT'S WHEN I WAS JUST

REALLY THROWN OFF, LIKE OKAY.

THIS IS SERIOUS.

>> Reporter: JESSICA DOCKED HER

BIKE AND RUSHED TO THE MERNEMERY

ROOM.

>> SHE HAD COME IN WITH SEVERE

PALPITATIONS AND CHEST PAIN

SYMPTOMS AND ALSO

LIGHT-HEADEDNESS AND DIZZINESS.

>> Reporter: DR. ASSAD MOHAMMED

WAS ON CALL AT MOUNT SINAI WEST.

HE SAYS JESSICA HAD AN ABNORMAL

HEART RHYTHM CALLED ATRIAL

FIBRILLATION, OR AFIB.

>> HE SAID THIS IS REALLY

SERIOUS, YOUR FAMILY NEEDS TO

GET DOWN HERE.

>> Reporter: CONCERNED ABOUT

BLOOD CLOTS AND A POTENTIAL

STROKE, DOCTORS HAD TO USE

ELECTRICAL CURRENTS TO SHOCK

JESSICA'S HEART INTO A NORMAL

RHYTHM.

IT WORKED.

AND THE NEXT DAY SHE WAS ABLE TO

GO HOME.

>> THE APPLE WATCH OR OTHER

WATCHES ARE VERY HELPFUL BECAUSE

THEY PROVIDE PATIENTS WITH A

VERY QUICK ALERT SYSTEM FOR THEM

TO SEE A HEALTH CARE PROVIDER.

>> Reporter: IF NOT FOR THE

ALERTS ON HER WATCH JESSICA SAYS

SHE WOULD HAVE JUST GONE HOME

AND TAKEN A NAP.

INSTEAD SHE CREDITS THE APPLE

WATCH FOR TURNING HER LIFE

AROUND.

>> EVEN WHEN IT SUCKS IT FEELS

GOOD.

>> Reporter: SINCE THE HEALTH

SCARE LAST MAY JESSICA'S DROPPED

100 POUNDS AND ADOPTED A HEALTHY

LIFESTYLE.

TRAINING TO RUN HER VERY FIRST

MARATHON, THIS WEEKEND'S POTOMAC

RIVER RUN IN D.C., WHICH FALLS

EXACTLY ONE YEAR --

>> MOUNT SINAI.

>> Reporter: -- SINCE SHE WAS

DISCHARGED FROM THE HOSPITAL.

>> WOULDN'T EVEN CROSS MY MIND.

>> Reporter: JESSICA'S BEEN

DOCUMENTING HER JOURNEY ON

SOCIAL MEDIA TO INSPIRE OTHERS

TO PAY ATTENTION TO THEIR

HEALTH.

AND YOU'LL NOTICE IN ALL THE

VIDEOS SHE'S WEARING HER APPLE

WATCH, AND SHE CERTAINLY WILL BE

FOR ALL 26.2 MILES.

>> I ABSOLUTELY WILL BE, YES.

I'M NEVER TAKING IT OFF.

I TAKE IT OFF TO CHARGE AND

THAT'S IT.

>> DR. MOHAMMED SAYS THAT AFIB

IS REALLY AMONG THE MOST COMMON

HEART ABNORMALITIE ABNORMALITIE.

BUT JESSICA'S HEALTHIER

LIFESTYLE YOU SAW THERE WILL

CERTAINLY HELP LOWER HER RISK OF

ANOTHER SCARE.

ANOTHER REMINDER TO LISTEN TO