Medtronic Inc. continued selling flawed cardiac defibrillators for two years after learning that some of them may suddenly quit working, according to company documents filed in a California lawsuit.

After Medtronic last year recalled the devices, 19,000 people had to have surgery for a replacement, said Medtronic spokesman Rob Clark. At least one of them died from post- surgical complications, according to the man’s widow. Defibrillator patients are vulnerable to potentially fatal heartbeat irregularities, which the $20,000 devices detect and correct using electrical shocks.