Faulty design resulting in temporary pacemaker failure

A 77-year-old man became asystolic 3 days after aortic valve replacement an d coronary artery bypass surgery. A dual-chamber temporary pacemaker genera tor was turned on but failed to discharge; instead, an obscure error messag e appeared on the liquid crystal display of the pacemaker. The intensive-ca re nurses and physicians were unable to activate the pacemaker. We describe the pacemaker design that led to this instance of pacemaker failure. This case is important because it illustrates how a medical equipment design fla w can turn a human error into a potentially catastrophic event.