A special catheter is inserted into the aortic arch containing a balloon that can be rapidly inflated and
deflated by a low-viscosity gas, usually helium. The timing of the balloon inflation is synchronized
to either the patient’s ECG or blood pressure waveform. Its primary purpose is
to improve perfusion of the heart muscle by inflating the balloon as the aortic valve opens,
providing additional backpressure to the carotid arteries and rapidly deflating it so that the
rest of the body can be perfused. This procedure sustains the patient as the myocardium
can recover sufficiently to pump on its own. In the event that a replacement heart is
required, the procedure will extend a patient’s life until a donor heart is available.
Alternatively, there are a number of LVADs that enhance the pumping action of the left
ventricle until a donor organ is found (Rosenberg, 1995). They are surgically implanted
in the patient’s chest or abdomen and are managed by the ICU staff. Less widely used,
though available also, is the extracorporeal membrane oxygenator (ECMO), or heart lung
machine (Dorson and Loria, 1988). This device, used during coronary-artery bypass graft,
can provide both respiratory and circulatory function, allowing the heart and lungs to be
mechanically inactive for a time. Efforts such as this are extreme and require significant
technical support during use.