| The most recognized risk associated with the HeartMate II is thrombosis. In the presence of developing clot, the HeartMate II Display Monitor and System Controller senses a decrease in pump flow and is accompanied by audible and visual alarms when flow rates drop below a certain threshold; however, when flow is completely inhibited, the Display Monitor and System Controller both fail to indicate that flow has reduced to zero and does not produce any corresponding alarms. To test the efficacy of the HeartMate II alarms, the Donavan Mock was used to simulate the hemodynamics of a typical heart failure patient. The hemodynamics were then improved by the addition of the HeartMate II LVAS. Partially occluding the inflow and outflow of the HeartMate II did display changes in flow and presented with alarms when appropriate; however, complete occlusions of the device failed to produce any alarms or accurate changes in flow. |
