Firefighters are giving emergency treatment to heart attack victims as part of an enhanced medical role after the July 7 bombings.
More than 5,000 firefighters have undergone training in how to use the life-saving equipment, including defibrillators used to restart the heart, and from today it is being carried by all 169 London fire engines.
Crew members will not respond to medical emergencies instead of ambulances but will use the equipment if they are first on the scene, or where paramedics cannot reached trapped victims.
It follows recommendations made by Coroner Lady Justice Hallett, who presided over the inquests into the deaths of 52 victims of the Tube and bus bombings in London on July 7, 2005, recording her verdict of unlawful killing in May this year. She supported the provision of first aid and emergency equipment across the Underground.
During the roll-out of the scheme across the brigade's 113 stations, defibrillators, which administer an electric shock to the heart, were used on four occasions, and managed to keep the patient alive until an ambulance crew arrived.
New equipment was also utilised a further 28 times to check patients' breathing. A large number of casualties rescued by the brigade have inhaled smoke. Oxygen supplies are also being carried. Firefighters have administered oxygen to patients on more than 400 occasions since 2007.
Some busier fire stations have used the new equipment for some time but the four-year roll-out to all 33 boroughs was being completed today, with the inclusion of Waltham Forest stations.
Gordon Fielden of the Fire Brigades Union said: "We are now trained to a level that is better than it was 10 years ago." However, he added: "We have always said money needs to be invested in first responders from the ambulance service."
Brigade instructors have been trained by the London Ambulance Service, and its experts continue to monitor firefighters to ensure they can operate the equipment correctly. The ambulance service also maintains the kit and replaces used items.
The kit includes manual suction devices to clear blocked airways, neck collars, improved wound dressings, and airway adjuncts, which help to maintain a clear airway in an unconscious patient.
Susan Hall, chairman of the London fire authority's community safety committee, said: "Following the 7/7 bombings, the emergency services were keen to learn how things could be done differently." She said that London crews' equipment and first aid training are now "the envy of fire brigades across the country".