A couple of years ago, Sheppard was in her garage putting away items she had exhibited in a pottery show earlier in the day. Her daughter, Joan Stauffacher, also a show exhibitor, was in the kitchen when she heard a crash followed by a thud coming from the garage. She found her mother lying unconscious on the floor as a result of sudden cardiac arrest and called 911. Within three minutes fire department personnel were at Sheppard's side using an automated external defibrillator (AED) to shock or "jump-start" her heart, before sending her off to El Camino Hospital.

According to the American Heart Association, 350,000 people die of sudden cardiac arrest each year without being hospitalized - more than 680 Americans a day. Most of these sudden deaths are caused by cardiac arrest, usually from a rapid, uncoordinated fibrillating - a quivering or twitching of the heart's lower chambers. The problem, called ventricular fibrillation, prevents the heart from pumping blood effectively. If it isn't reversed within a few minutes, the victim may die.

The survival rate of those who have out-of-hospital cardiac arrests is strongly influenced by time to defibrillation, because most of the damage to the heart occurs in the first hour of an attack. The sooner normal heart rhythm is restored, the better the chance of survival and recovery. Early defibrillation is a crucial link in the chain of survival.

Luckily, Sheppard lives two blocks from the fire department and all Sunnyvale fire stations are equipped with AEDs.

AEDs are lightweight, portable devices that deliver a small electric shock to the heart after electronically assessing and detecting ventricular fibrillation (quivering) or rapid ventricular tachycardia (a heart rate of more than 100 beats per minute). According to Sunnyvale Police Lt. Steve Drewniany, the device is standard equipment in Sunnyvale police and fire vehicles, government offices, public buildings, senior and community centers, pools, golf courses, libraries, schools, recreation departments and other places where large numbers of people congregate.

AEDs, which restore normal heart rhythm during a sudden cardiac arrest, have been used on people as young as 20, but the largest percentage of people who have been helped are over age 70, reports Drewniany. The AED is a little smaller than a laptop computer and easy to use.

"The operator turns the unit on and places two pads on the victim's chest," he says. "The AED does the rest, first assessing to see if the heart is beating normally. If it is, no electric charge will be delivered, but if the heart is fibrillating or quivering, the AED voice-prompts the operator to push a shock button." If normal rhythm is not restored, the unit automatically delivers a second shock. Sheppard's heart required three shocks before it started beating normally.

AED use by laypersons has developed widespread support. According to Julianne Brawner, R.N., MSN, AHA education services coordinator in Menlo Park, the device is simple enough for a sixth-grader to operate. In a study of AED use, fifteen 12-year-old children were compared with 22 emergency medical technicians and paramedics using special mannequins as subjects. The time from entry on the scene to delivery of the shock varied by only 15 to 31 seconds between the two groups, with no prompts given to the children (other than the importance of speed).

Because most cardiac arrests occur at home and the majority of cardiac death cases are due to ventricular fibrillation, some say the AED should be made readily accessible to the public for home use. FDA regulations specify that the AED can be purchased only with a prescription-like order from a doctor.

Senate Bill 911 provides immunity from civil liability to any person who, in good faith and without expectation of compensation, renders emergency care by using an AED if he or she has completed an approved basic AED course. Training is available through the American Red Cross, the American Heart Association and other groups.

It's not always easy to tell when a person is having a heart attack, but some symptoms to be aware of are: an uncomfortable pressure; squeezing, fullness or pain in the center of the chest that lasts more than a few minutes or goes away and comes back; discomfort in other areas of the upper body, which may be felt in one or both arms, the back, neck, jaw or stomach; shortness of breath; breaking out in a cold sweat; nausea; or light-headedness. If any of these symptoms last for more than five minutes, call 911.

In a recent newsletter, Fidelity Mutual Fund's Steve Calhoun, who manages the company's medical equipment and systems portfolio, touted the financial future of technological innovations, including medical systems, equipment, and cardio-rhythm management and defibrillation devices. Regular and wearable holster-style AEDs and implants such as pacemakers and defibrillators will see even wider use as the 76 million baby boomers head into their 60s.

The news gets even better for Sheppard, one of thousands of Americans who has received an implantable cardioverter-defibrillator (ICD) made by Guidant Corporation, located in Santa Clara. A few months after Sunnyvale fire department personnel shocked her heart with an AED and sent her off to the hospital for treatment, Sheppard resumed a somewhat normal life. However, she no longer had the energy to start new pottery projects or go square dancing with her husband. That condition changed dramatically after she learned from Dr. Sung Chun that she was a good candidate for an implantable defibrillator to monitor and manage her heartbeats utilizing the ICD technology that has been in use for 20 years.

As a cardiac electrophysiologist at Stanford University's School of Medicine, Dr. Chun implants about 120 ICDs a year, often in patients who also have pacemaker implants. Most implant patients are in their 70s and 80s and check in at Stanford four times a year. "The small, pager-size ICD is a lifesaving device because of the threatening prognosis related to congestive heart failure and other serious heart diseases," Chun says.

Sheppard's ICD has done its lifesaving work twice, and she definitely heard and felt it both times, once being knocked to the floor when her ICD was shocking her heart. But the implant has changed Sheppard's life for the better. She now works part time, has resumed her pottery, dances four nights a week and does educational presentations about the AED. "I owe all this to the Sunnyvale fireman, Tim Macierz, who came to my rescue with the AED in the first place," she says.

AEDs have a 97 percent success rate in terminating ventricular fibrillation, yet fewer than half of the nation's ambulance services, 10 to 15 percent of emergency service fire units, and less than 1 percent of police vehicles are equipped with them, reports the American Heart Association. In order to save more lives each year, public access defibrillator programs must be more widespread. Communities that have implemented public access programs have achieved high survival rates for out-of-hospital cardiac arrests. In a study conducted in the casinos of Las Vegas, the public access defibrillation program achieved survival rates as high as 74 percent if patients received defibrillation within 3 minutes and 49 percent for those receiving defibrillation after more than three minutes.

Public buildings in the city of San Jose and Norman Y. Mineta San Jose International Airport are well-equipped with AEDs, as are San Francisco International Airport, Moffett Air Field Base, all local police and fire department vehicles in Santa Clara County, and many local fitness centers and recreation facilities. But there could be more. The U.S. Department of Health and Human Services has $5 million a year to give away in grants to municipalities, private companies, schools and other appropriate groups to invest in AED equipment and training over the next five years.

Heart resources

  Information about AED:

www.early-defib.org

  Medtronic, manufacturer of AED: 925.609.1770, www.medtronic.com

  Guidant Corp., manufacturer of ICD: 408.845.3000, www.guidant.com

  Stanford University School of Medicine Pacemaker Service:
650. 723.6459

  American Heart Assocation: 408.977.4950, www.americanheart.org

  Heartshare, American Heart Association and AED training: 408. 246.0311 or 650.321.6500

  American Red Cross, CPR and AED training: 408.577.1000