The number of patients whose deaths might be linked to the failure of medical devices has tripled in five years, according to the Department of Health.
There were 141 fatalities reported last year - up from 92 in 2000 and only 47 in 1997 - although officials insisted that the equipment might not be to blame in all cases.
The big rise was confirmed as stocks of heart valve testers were recalled by the manufacturer after a patient died when one broke during an open heart operation at the Northern general hospital, Sheffield.
The devices check mechanical heart valves after they have been sewn into the body. Part of the plastic head broke off and the fragment could not be found. The hospital reported finding cracks in the heads of other testers which are reusable after sterilisation although multiple reprocessing is said to lead to cracking of the plastic eventually.
The health department and its medical devices agency (MDA) declined to give further information, including about the sex and age of the patient, saying confidentiality must be maintained.
Manufacturers Sulzer Carbomedics are said to be assessing the use of a more durable plastic.
About 7,000 heart valve replacements are carried out each year and the MDA said this was the first incident of its kind that had been reported. "There are no safety implications for patients who have already successfully undergone this sort of surgery."
The number of "adverse incidents" reported in all to the agency rose from 5,383 in 1997 to 7,896 in 2001, a less dramatic increase than those that in volved deaths. The agency and the health department declined to reveal in which category of equipment most deaths occurred. "It is important to realise that just because an incident involving a fatality and a medical device is reported, it does not necessarily implicate the device. Evidence has shown that 25% of all reports received are not linked to the device."
Their joint statement said more incidents were being reported following attempts to persuade more people to report them as part of a "no blame" culture.
The health department usually declines to give much information about safety warnings. An exception was the rethink ordered last April on the administration of chemotherapy following the death of a leukemia patient who was accidentally given a drug in his spine rather than a vein.
But it is worried about a number of reports involving the muffling of alarms and other "inappropriate human action" to equipment monitoring critically ill patients and the blocking of breathing systems. Hospitals and nursing homes have been warned about the safety of bed rails, which have caused 15 deaths in five years.
Other areas of concerns include the increased number of patients being burned while having scans. Electrical faults have also been found in operating theatres. Faults on wheelchairs are also considerable.
The agency's annual report says it "aims to help prevent incidents happening and does not look to assign blame. No device will ever be 100% safe and constant effort is needed to reduce the rate at which incidents occur."
