Nearly 4,000 tests for heart disease performed over the last three years at Harlem Hospital Center were never read by doctors charged with making a diagnosis, hospital officials acknowledged. The echocardiogram tests were ordered by doctors at the hospital. The tests were stored on a computer and basically forgotten, officials said. The lapse occurred because the cardiology service at the hospital had developed a system by which technicians were given the responsibility to scan all tests and flag any that looked abnormal, so that they would be given priority when doctors read them. It appears, officials said, that the tests that were not flagged were put aside and forgotten, the New York Times reports.