Mechanical Circulatory Support

LVAD (left ventricular assist device) HeartMate II

LVAD (left ventricular assist device) HeartMate II
Long-term, non-pulsatile, implantabile mechanical circulatory support
by Thoratec

In the case of patients suffering from acute decompensated heart failure, such as acute myocardial infarction, or patients in the terminal stages of chronic cardiac failure, such as dilated cardiomyopathy, mechanical circulatory support is provided for the blood circulation in an attempt to ensure adequate macro- and microcirculation to cover the metabolic needs of the patient’s peripheral tissues. These support devices are divided into pulsatile and non-pulsatile devices according to the type of flow they generate. They are further divided into mechanical circulatory support devices to support systemic circulation after left ventricular failure and mechanical circulatory support devices to support pulmonary circulation after right ventricular failure. Bilateral heart failure requires the implantation of both mechanical circulatory support devices to support systemic and pulmonary circulation.

The mechanical circulatory support devices are distinguished by pump location into implantable, when the pump lies inside the patient, and paracorporal, when the pump is outside the patient. They can also be broken down by duration into temporary and long-term support devices. Temporary support devices are used when myocardial function is expected to be recovered, and the pump can then be removed. Long-term support is used as a “bridge to transplantation”, which means it helps to pump blood in the patient’s circulation until such time as a suitable donor can be found. The support device is then removed, together with the failed heart, and a new heart is transplanted. The period during which long-term support devices can be used is generally a question of months, exceptionally stretching over years. No long-term mechanical support device that can be implanted for a number of years and that is associated with a good quality of life, with no undesirable side-effects, currently exists.

Undesirable side-effects after implantation of mechanical circulation support devices include infections, sepsis, haemorrhagic and embolic complications, such as cerebro-vascular accidents, bleeding into the digestive tract, bleeding into the lungs and similar, right-sided failure after implantation of only mechanical circulatory support device to support systemic circulation and death. “Destination therapy” means implantation of mechanical circulatory support with intent to permanently supplement or replace the native heart.

Also a presentation on implantation 2 VAD as TAH is available for download (in Czech language).