HeartWare International (NSDQ:HTWR) has issued an urgent recall for certain computerized controllers for its ventricular assist devices over concerns that they may malfunction and cause the heart pump to stop.

HeartWare said the recall affects controllers that were distributed before the product's 2012 FDA approval. The company said the older controllers are more susceptible to electrostatic discharge, which can cause the system to malfunction.

The recall covers controllers with the product codes 1400 and 1401XX that were distributed during the company's ADVANCE and ENDURANCE clinical trials. HeartWare is advising clinicians to assess patients to determine if they should receive new controllers.

Approximately 120 U.S. patients are affected by the recall.

In 2013, HeartWare issued a Field Safety Correction Action for the devices over electrostatic concerns. As part of that action, HeartWare sent a notice to patients and clinicians instructing them on how to reduce the risk of electrostatic disturbances, such avoiding materials and devices that are prone to conducting static electricity. Since that time, electrostatic discharge is believed to have played a role in the death of one patient and the serious injury of another, according to the company.

Last June, HeartWare received a FDA warning letter over quality control issues at its manufacturing facility in Miami Lakes, Fla.