I think it is probably fair to say we suspect lives may well be being lost

Dr Charles Deakin

Training gap

But the research suggests only two in 10 doctors of all grades and specialities know where to place one of the defibrillator paddles and just six out of 10 knew where to place the other.

There are now calls for all doctors to get full training in using the vital equipment.

Delays in treatment could be costing lives

Report author Dr Charles Deakin studied 101 doctors from all grades and specialities at Southampton General Hospital and said he was "surprised" by the high levels of ignorance in such a critical area.

He said he was sure the lack of knowledge was country-wide.

"I think it is probably fair to say we suspect lives may well be being lost.

"We suspect this is probably affecting the outcome but we have no evidence of this."

Dr Deakin said the positioning of the paddles was vital to ensure the correct electrical current was passed through the heart to restart it.

He said if the paddles were placed too far apart there could be delays in getting the heart started and as the current was increased patients could suffer unnecessary skin burns.

He said even the smallest delays could lead to death, with every minute of delay in restoring the normal heart rhythm increasing mortality by between seven and 10%.