Wireless transmission of ECGs could speed up heart attack diagnosis

Norbert von der Groeben

Palo Alto Fire Department paramedic Sean MacDonald carries a Lifepak-15, one of the two new devices that Stanford Hospital & Clinics helped obtain for the department. It has the ability to transmit ECG readings wirelessly.

A high-tech system that allows physicians to receive heart data from paramedics in the field is now live at Stanford Hospital & Clinics.

The system, which launched March 1, enables Stanford emergency physicians to examine a patient’s electrocardiogram, or ECG, before that patient even departs in the ambulance for the hospital. It also gives the hospital an opportunity to assemble a team of cardiovascular nurses and interventional cardiologists for the artery-widening procedure — balloon angioplasty, which is used to treat severe heart attacks — before the patient arrives.

“We predict it will translate into better emergency cardiac care for the community,” said Donald Schreiber, MD, director of quality improvement in Stanford’s Division of Emergency Medicine.

The move is the latest development in a two-year effort by the hospital’s emergency medicine and interventional cardiology teams to reduce so-called “door-to-balloon times.” This is the length of time it takes for doctors and nurses to diagnose and treat heart attack patients, from the moment they are admitted to the emergency department to the moment a balloon catheter is used to open up the blocked artery responsible for the heart attack.

Fast treatment is vital for patients with artery blockages that cut off oxygen to a large portion of the heart; the more time passes, the more heart muscle is damaged, the more the patient’s life is at risk. 2010 was the first year that 100 percent of such patients arriving at Stanford Hospital’s emergency department had door-to-balloon times of 90 minutes or less; the average time was just 61 minutes. (The American College of Cardiology and American Heart Association recommend that hospitals aim for door-to-balloon times of no more than 90 minutes at least 75 percent of the time.) Stanford physicians credit increased dialogue and collaboration with local paramedics as one key reason for the perfect score.

Schreiber helped to institute the new system for receiving ECG transmissions at Stanford Hospital.

“We worked hard internally on our processes, and we’ve also partnered with the Palo Alto Fire Department and other local paramedics to improve our communications and streamline how they transfer patients to us,” said David P. Lee, MD, director of the Cardiac Catheterization and Coronary Intervention Laboratories. “Time is muscle, and the earlier we can deliver appropriate care to patients, the better.”

Kim Roderick of the Palo Alto Fire Department agreed. “It’s been good for doctors to get a better sense of the uncontrolled environment our paramedics work in, and it’s been good for us to get a better understanding of their expectations on the clinical side,” she said.

Wireless technology for transmitting ECGs has the potential for enabling Stanford doctors and nurses to respond to heart attacks even more quickly and efficiently. Although the portable monitor/defibrillator — a boombox-sized device you often see with paramedics treating someone in the field — has long been a fixture on ambulances, its ability to share ECGs with medical personnel who are not at the scene has greatly advanced with the growth and sophistication of wireless broadband technology over the last several years.

Stanford Hospital is adopting a system made by Physio-Control Inc. of Redmond, Wash., that has been on the market for about two years. For it to work, paramedics need a “LifePak” heart monitor/defibrillator with a wireless modem, and a hospital needs web-based software called LifeNet, which receives the ECG data and distributes it to computers and even doctors’ smart phones. To try out the system, Stanford Hospital has helped the Palo Alto Fire Department secure two of the latest LifePak devices, which cost about $30,000 each, for a one-year trial period. A few other local emergency medical responders, including the Mountain View Fire Department and American Medical Response of San Mateo County, already use LifePak devices capable of sending ECGs.

Stanford Hospital and the Palo Alto Fire Department will conduct a one-year trial in which they will collect data to measure whether the devices improve the process of diagnosing and treating heart-attack patients. Based largely on these results, the hospital then will decide whether to continue using the Physio-Control system. 

John Sanford is a writer in the communications office at Stanford Hospital & Clinics.