Systems and methods for selectively occluding the superior vena cava for treating heart conditions
Systems and methods and devices are provided for treating conditions such as heart failure and/or pulmonary hypertension by at least partially occluding flow through the superior vena cava for an interval spanning multiple cardiac cycles. A catheter with an occlusion device is provided along with a controller that actuates a drive mechanism to provide at least partial occlusion of the patient's superior vena cava, which reduces cardiac filling pressures, and induces a favorable shift in the patient's Frank-Starling curve towards healthy heart functionality and improved cardiac performance. The occlusion device may include a lumen obstructed by a relief valve that may permit fluid flow through the occlusion device to release an excessive build-up of pressure.
1. A system for providing improvement in cardiorenal function for a patient, the system comprising:
a catheter having a proximal end and a distal region, the catheter configured for intravascular placement so that the distal region is disposed in a superior vena cava (SVC) of the patient;
a flow limiting element disposed on the distal region of the catheter, the flow limiting element sized and shaped to fully occlude the SVC and configured to be selectively actuated to fully occlude the SVC; and
a controller configured to be operatively coupled to the catheter, the controller comprising instructions that, when executed by one or more processors of the controller, cause the controller to intermittently actuate the flow limiting element to fully occlude the SVC for a first predetermined time interval spanning multiple cardiac cycles and to contract for a second predetermined time interval spanning multiple cardiac cycles to create a negative pressure sink in a right atrium of the patient sufficient to accelerate flow from a renal vein, thereby enhancing renal decongestion and promoting blood flow across a kidney of the patient,
wherein the first predetermined time interval is at least one minute and at least five times greater than the second predetermined time interval.
2. The system of claim 1 , further comprising:
a first pressure sensor disposed on the catheter proximal to the flow limiting element, the first pressure sensor outputting a first pressure signal; and
a second pressure sensor disposed on the catheter and distal to the flow limiting element, the second pressure sensor outputting a second pressure signal,
wherein the controller is configured to generate a first signal corresponding to a difference between the first pressure signal and the second pressure signal, the first signal indicative of a degree of occlusion of the flow limiting element.
3. The system of claim 2 , wherein the second pressure sensor is positioned between an azygos vein occlusion balloon and the SVC occlusion balloon, the system further comprising a third pressure sensor disposed on the catheter distal to the azygos vein occlusion balloon, the third pressure sensor configured to output a third pressure signal and the controller is configured to generate a second signal corresponding to a difference between the second pressure signal and the third pressure signal, the second signal indicative of a degree of occlusion of the azygos vein.
4. The system of claim 2 , wherein the controller is configured to use the first signal to determine when to actuate the flow limiting element to fully occlude the SVC and when to cease actuation of the flow limiting element.
5. The system of claim 1 , further comprising an azygos vein occlusion balloon disposed on the catheter proximal to the flow limiting element, wherein the flow limiting element is an SVC occlusion balloon.
6. The system of claim 5 , wherein the azygos vein occlusion balloon is configured to be selectively actuated to at least partially occlude an azygos vein of the patient.
7. The system of claim 6 , wherein the azygos vein occlusion balloon and the SVC occlusion balloon are independently actuated.
8. The system of claim 1 , wherein the controller is configured for implantation.
9. The system of claim 1 , wherein the flow limiting element is an SVC occlusion balloon.
10. The system of claim 1 , wherein the first predetermined time interval is 4-6 minutes and the second predetermined time interval is 1-30 seconds.
11. The system of claim 1 , wherein the flow limiting element comprises an inflatable cylindrical balloon having a relief valve coupled to the inflatable cylindrical balloon, and wherein the relief valve has an open and closed position.
12. The system of claim 11 , wherein the relief valve is configured to open at a pressure between 30-60 mmHg to permit fluid to flow through the SVC to a right atrium of the patient.
13. The system of claim 11 , wherein the relief valve is a binary valve configured to rapidly transform to an open position upon application of a pressure force beyond a certain threshold.
14. The system of claim 11 , wherein the relief valve is a gradual valve configured to gradually transform to an open position as a pressure force applied to the relief valve increases.
15. The system of claim 1 , wherein the system is configured for use in combination with a ventricular assist device (VAD) for improving efficiency and functionality of the VAD.
16. The system of claim 1 , wherein the controller is configured to intermittently actuate the flow limiting element to reduce cardiac preload during the interval sufficiently to improve cardiac performance as measured by at least one of: reduced cardiac filling pressures, increased left ventricular relaxation, increased left ventricular capacitance, increased left ventricular stroke volume, increased lusitropy, reduced left ventricular stiffness, or reduced cardiac strain.
17. The system of claim 1 , wherein the first predetermined time interval is at least ten times greater than the second predetermined time interval.
18. The system of claim 17 , wherein the first predetermined time interval is 4-6 minutes and the second predetermined time interval is 1-10 seconds.
19. A method for providing improvement in cardiorenal function for a patient, the method comprising:
intravascularly placing a flow limiting element disposed on a distal region of a catheter into a superior vena cava (SVC) of the patient; and
intermittently actuating the flow limiting element responsive to instructions programmed in a controller to expand the flow limiting element to fully occlude the SVC for a first predetermined time interval spanning multiple cardiac cycles and to contract for a second predetermined time interval spanning multiple cardiac cycles, wherein the first predetermined time interval is at least one minute and at least five times greater than the second predetermined time interval,
wherein intermittently actuating the flow limiting element creates a negative pressure sink in a right atrium of the patient sufficient to accelerate flow from a renal vein, thereby enhancing renal decongestion and promoting blood flow across a kidney of the patient.
20. The method of claim 19 , wherein the first predetermined time interval is 4-6 minutes and the second predetermined time interval is 1-30 seconds.
21. The method of claim 19 , wherein intermittently actuating the flow limiting element is done while using a ventricular assist device (VAD) for improving efficiency and functionality of the VAD.
22. The method of claim 19 , wherein the flow limiting element is an SVC occlusion balloon.