LEFT VENTRICULAR ASSIST DEVICE

Left Ventricular Assist Device

Left Ventricular Assist Device

Since the transplant as standard procedure for heart failure treatment was established, the few donors' availability turned into biggest limitation in view of the increasing demand. This situation, concomitant obtained with the relevant results with mechanical circulatory assist devices promoted the use of these devices as an option so much as survive to improve the quality of life of the patients with advanced heart failure. Nowadays the medical technology offers a wide range of medical devices, with diverse characteristics and specifications of application, which go from the fixings for per-coetaneous way up to the surgical one. Unfortunately, the advances achievement in the treatment of the heart failure with the mechanical devices have been evaluated only in the physiological environment, leaving of side the biomechanical aspect, for what seems that STI (Successful Therapeutic Impediments) results are not always beneficial. It is important to do an integrated analysis of this cardiac therapy, which includes the biomechanical environment, to understand ITS functionality and to make use of the potential that have showed these medical devices in the cardiac-circulatory assistance.

The progress achieved in recent decades, as to what relates to cardiovascular treatments has been spectacular. This is true from the point of view as interventional or surgical treatment from the drug. So there have been major improvements in survival rates. Citing the example of left ventricular assist device was observed that survival has improved by 10 percentage points and even the rates of development of cardiac problems in this context have been halved. However, the increased survival associated with heart problems logically has led also to a greater number of patients who survive with systolic dysfunction and therefore associated with congestive heart failure. Thus, heart failure is now the main disease that causes cardiovascular income and is related to significant morbidity. All of these circumstanmces and situations are need to be understood in order to understand the market for LVAD.

To evaluate the performance of left ventricular assist device (LVAD) ti is necessary to compare functional and operational characteristics with those of its biological counterpart, and define the biomechanical conditions to be met for an assistive device that emulates the operation of the heart native. From this comparison we obtain the parameters of cardiac pump function, which serve as criteria for the design and operation control of assistive devices such as cardiac output, ejection pressure, energy demand and operational efficiency.

Heart function as hydraulic pumps, is described with the positive displacement principle, whereby the expulsion of liquid due to the change of volume of the chamber containing it, which involves producing a pulsate flow 14. However, it operates as a mechanical displacement pumps due to the visco-elastic nature of self-regulation infarction and stroke volume with filling. The heart can maintain constant cardiac output to changes in vascular resistance within the range of normal pressures, and above this range, increases in pressure causes decreased cardiac output, following the principle of conservation of momentum the self-governing inverse of the ...