The four electrode pads found on David Kelly's chest at a post-mortem examination indicate that he had recently had an electrocardiogram (ECG) test to check his heart rhythm, probably on the morning that he died.

He might have experienced palpitations or other unusual symptoms, possibly brought on by stress, which led him to consult his GP, who would have referred him for the test.

For the test, four pads are attached to the chest and the heart beat recorded on an ECG machine, for later interpretation by a cardiologist. As Dr Kelly had established coronary heart disease, it is possible he would have had the test in the past. It may have been that the nurse at the hospital where the test was carried out left the pads in place for Dr Kelly to remove in the shower later. For men with hairy chests, removal can be uncomfortable.

Where patients are suffering symptoms which occur at unpredictable intervals, a cardiologist may order a 24-hour ECG. For this test, the pads on the chest are attached to a portable monitor like a small Walkman, worn on the belt, which records the heart's activity round the clock.

After 24 hours, the device is returned to the hospital or GP and the information downloaded. However, no mention was made yesterday of the portable ECG monitor being found with the body or of wires attached to the chest pads.

A spokeswoman for the British Heart Foundation said: "A 24-hour ECG is the only way to get a full picture of the heart's rhythm. The other possibility is that a nurse sent him home after an ordinary ECG test with the pads still attached."