SHANGHAI, Aug. 21 -- CHINA has returned a shipment of pacemakers imported from the United States because of quality problems, the country's standards watchdog reported yesterday.

The General Administration of Quality Supervision, Inspection and Quarantine said the 272 pacemakers, which were valued at about US$240,000 and detained by Shanghai Entry-Exit Inspection and Quarantine Bureau at the end of April, did not meet standards.

The administration said the pulse strength of the devices, made by St Jude Medical Inc, was not in line with its indicated properties.

The difference between the testing parameters and the default ones exceeded the two-percent limit set by the Chinese technical authorities, the AQSIQ said.

"The pacemakers pose potential threats to patients' lives as they could cause misdiagnosis," the administration said on its Website (www.aqsiq.gov.cn).

The quality inspection watchdog also announced yesterday it was creating an inspection database of imports and exports to help strengthen product safety.

Central authorities had asked supervision and inspection departments around the country to strengthen the vetting of imports and "guarantee that the quality of imported products, especially those that touch upon human health and safety, meet standards."

The agency is developing a database to integrate inspection and quarantine information about imports and exports, the official Xinhua news agency reported.