A team from the Scottish Ambulance Service has taken part in a project, led by medical experts at Edinburgh University.
The Resuscitation Rapid Response Unit analyses data from defibrillators and uses it to inform ambulance staff responding to cardiac emergencies.
The project started in April 2011 and the Ambulance Service said the rate of return of spontaneous circulation for cardiac arrest patients in Lothian is now 23.5% compared with the Scottish average of 17.5%.
A small device is used to measure CPR as it is administered to patients and prompts changes in technique during resuscitation if required.
The average response time in Scotland for a cardiac-related 999 call is six minutes, and last year ambulance crews successfully saved the lives of 523 patients in cardiac arrest.