Apparatus, systems, and methods for percutaneous pneumatic cardiac assistance

A method for assisting cardiac function in a patient suffering from heart failure, said method comprising:

• detecting the patient's electrocardiogram (ECG) to determine a cardiac rhythm;
• percutaneously accessing an implanted port with a cannula;
• alternately delivering and withdrawing a driving gas through the cannula to the implanted port which is connected to a pneumatic effector implanted to only a space beneath the patient's pericardial sac and over a myocardial surface overlying the patient's left ventricle and to selectively expand and contract within said space, wherein the pneumatic effector is elliptical in shape and has a length configured to extend along a major portion of the ventricular cavity;
• wherein the alternately delivering and withdrawing of the driving gas is synchronized with the determined cardiac rhythm to cause the pneumatic effector to compress and decompress the heart at a rate which matches the cardiac rhythm.

An implantable cardiac assist catheter for use with an external drive unit, said implantable cardiac assist catheter comprising:

• a catheter body having a proximal end and a distal end, the catheter body being configured to be advanced through a subxiphoid puncture site and then across a patient's left ventricle;
• a pneumatic effector proximal of the distal end of the catheter body and configured to be implanted to only a space beneath a patient's pericardial sac and over a myocardial surface overlying the patient's left ventricle, wherein the pneumatic effector is further configured to selectively expand and contract within said space, and wherein the pneumatic effector is elliptical shape and has a length configured to extend along a major portion of the ventricular cavity;
• and
• an implantable port at the proximal end of the catheter and configured to receive a percutaneously introduced cannula, said port being connected to supply a driving gas received from the cannula through a gas lumen in the catheter body to the pneumatic effector.

An external drive unit for use with an implantable cardiac assist catheter, said external drive unit comprising:

• (a) a pump assembly configured to alternately (i) deliver the driving gas to a pneumatic effector of the implantable cardiac assist catheter during cardiac systole to expand the pneumatic effector and (ii) withdraw the driving gas from the pneumatic effector during cardiac diastole to contract the pneumatic effector,
• wherein the pneumatic effector is configured to be implanted to only a space beneath a patient's pericardial sac and over a myocardial surface overlying the patient's left ventricle, wherein the pneumatic effector is further configured to selectively expand and contract within said space, and wherein the pneumatic effector is elliptical in shape and has a length configured to extend along a major portion of the ventricular cavity;
• and
• (b) control circuitry configured to operate the pump assembly to actuate the pneumatic effector on the implantable cardiac assist catheter in synchrony with the patient's cardiac rhythm as measured by an electrocardiogram (ECG).