Devices and methods for absorbing, transferring and delivering heart energy

#Heart failure is a serious disease that is caused by deterioration of ventricular muscle. This deterioration ultimately reduces the ability of the heart to pump blood, causes a number of severe symptoms, and results in a high mortality rate.

#Many heart failure patients have left ventricular dysfunction wherein the left ventricle is diseased while the right ventricle remains relatively healthy. Because the right and left ventricle are fluidly connected in series, both ventricles must pump the same amount of blood. Therefore with left ventricular dysfunction, the healthier right ventricle is forced to reduce its output to that of the left ventricle. The mechanism by which this occurs is a significant increase in blood pressures against which the right heart must work. Over time, this additional stress on the right ventricle can cause right ventricular dysfunction.

#Various electric and pneumatic pumps have been proposed that assist failing hearts in pumping blood. Left ventricular assist devices, for example, remove blood from the left ventricle and pump into the aorta, thereby unloading the diseased left ventricle and improving cardiac output. Because the right heart is often healthy, often no assist is provided to the right ventricle. Since assist devices must put energy into pumping blood, an energy source is required. This energy source is usually electric. Reliably providing the amount of energy needed to assist the heart significantly increases the complexity of these assist devices. Power systems often include an electric pump, an internal battery, external batteries, chargers, control systems, and a skin port (for an electrical wire or vent) or transcutaneous energy transmission (TET) coils. These various components increase cost and can result in reliability and ease-of-use problems. In addition, the implantation of these components can be time consuming and difficult. Furthermore, the blood-contacting nature of many assist devices results in significant complications (e.g., stroke).

#FIG. 1 shows a device for assisting the heart in pumping blood which has an energy absorbing element and an energy delivering element

#FIG. 2 is a cross-sectional view of the energy absorbing element.

#FIG. 3 is a cross-sectional view of the energy absorbing element with a compressible element being compressed when the pulmonary artery expands.

#Referring to FIGS. 1-3, a device 2 for assisting the heart in pumping blood is shown. The device 2 has an energy absorbing element 4 which absorbs pumping energy of the heart. The device 2 also has an energy delivery element 6 which receives energy from the energy absorbing element 4 and uses the energy to provide pumping assistance to the heart. The energy delivery element 6 may include an expandable element 8 placed adjacent to an exterior surface of the left ventricle. The expandable element 8 applies pressure to the exterior surface of the left ventricle during contraction of the left ventricle to assist the left ventricle in pumping blood.

#The energy absorbing element 4 is configured and positioned to absorb pumping energy from the heart when the right ventricle is contracting. The energy absorbing element 4 may be positioned around at least a portion of a blood vessel that is part of the pulmonary arterial tree such as one of the pulmonary arteries. The energy absorbing element 4 has a compressible element 10 which is compressed when pressure increases in the blood vessel. The energy absorbing element 4 may have a substantially rigid collar or clip 12 which extends around the blood vessel with the compressible element 10 positioned on a radially inner side 15 of the collar 12 between the collar 12 and the pulmonary artery PA.

#The expandable element 8 of the energy delivery element 6 and the compressible element 10 of the energy absorbing element 4 may each contain a fluid 13. The fluid in the elements 8, 10 are in pressure communication with one another, either directly or indirectly, so that an increase in fluid pressure in the compressible element produces an increase in fluid pressure in the expandable element. The elements 8, 10 are coupled together via a tube 11 having a lumen 14 so that the same fluid 13 is transferred between the two elements 8, 10. The fluid 13 in the two elements 8, 10 may also be kept separate with a pressure communicating element, such as a flexible septum (not shown), which communicates fluid pressure between the two elements 8, 10 without mixing the fluids in the elements 8, 10.