Device and Method for Diagnosis of Cardiac Tamponade

Abstract

The invention relates to a system for challenging the pericardial space, to provide an indication of the risk of cardiac tamponade in a patient, as well as methods for diagnosis of, and determination of the extent of, a tamponade, and treating a patient in whom there is a detected cardiac tamponade.

Claims

1. A method, comprising: measuring one or both of a velocity or flow of blood through a left or right ventricular outflow tract, wherein the velocity or flow of blood through the left or right ventricular outflow tract is affected by inflation of a balloon; calculating blood flow through the left or right ventricular outflow tract; and providing an indication of a cardiac tamponade in a patient based on a relationship between a volume of inflation of the balloon and the blood flow through the left or right ventricular outflow tract.

2. The method of claim 1, wherein one or both of the velocity or flow of blood through the left or right ventricular outflow tract is measured with a Doppler probe.

3. The method of claim 2, wherein the Doppler probe is positioned on an outer surface of the left or right ventricular outflow tract to measure one or both of the velocity or flow of blood through the left or right ventricular outflow tract, respectively.

4. The method of claim 2, wherein the Doppler probe measures one or both of a velocity or flow of blood through the left or right ventricular outflow tract en face of the left or right ventricular outflow tract, respectively.

5. The method of claim 2, wherein the Doppler probe is positioned at a pulmonary artery bifurcation under an aortic arch to measure one or both of the velocity or flow of blood in the right ventricular outflow tract.

6. The method of claim 2, wherein the Doppler probe is placed on a surface of an aortic arch to measure one or both of the velocity or flow of blood in the left ventricular outflow tract.

7. The method of claim 1, wherein the balloon provides substantially even pressure across a heart comprising the left or right ventricular outflow tract when inflated.

8. The method of claim 1, wherein the balloon is inflated in a pericardial space, a mediastinal space, behind a sternum, or behind a heart of the patient.

9. The method of claim 8, further comprising determining a space available within any of the pericardial space, the mediastinal space, behind the sternum, or behind the heart of the patient.

10. The method of claim 1, further comprising removing all or part of an obstruction within a pericardial space, a mediastinal space, behind a sternum, or behind a heart of the patient.

11. A system, comprising: a probe, wherein the probe is configured to measure one or both of a velocity or a flow of blood through a left or right ventricular outflow tract; a balloon, wherein the balloon is configured to change the velocity or the flow of blood through the left or right ventricular outflow tract upon inflation; and a processing device communicatively coupled to the probe and the balloon, wherein the processing device is configured to calculate blood flow through the left or right ventricular outflow tract, wherein an indication of a cardiac tamponade in a patient is provided based on a relationship between a volume of inflation of the balloon and the blood flow through the left or right ventricular outflow tract.

12. The system of claim 11, wherein the balloon is further configured to: be placed in a pericardial space, a mediastinal space, behind a sternum, or behind a heart; and be inflated from a volume of 1 ml up to a volume of 250 ml.

13. The system of claim 11, wherein the probe is configured to be positioned on an outer surface of the left or right ventricular outflow tract such that the probe measures one or both of the velocity or flow of blood through the left or right ventricular outflow tract, respectively.

14. The system of claim 11, wherein the balloon is a pressure sensing balloon configured to determine resistance to inflation, or a degree of inflation of the balloon.

15. The system of claim 14, wherein the balloon comprises an integral sensor capable of sensing the degree of inflation of the balloon.

16. A system, comprising: a probe, wherein the probe is configured to measure one or both of a velocity or a flow of blood through a left or right ventricular outflow tract; a balloon, wherein the balloon is configured to change the velocity or the flow of blood through the left or right ventricular outflow tract upon inflation; and a processing device communicatively coupled to the probe and the balloon, wherein the processing device is configured to: calculate blood flow through the left or right ventricular outflow tract; generate a relationship curve between the blood flow through the left or right ventricular outflow tract and a volume of inflation of the balloon; and calculate a probability of a patient developing a cardiac tamponade based on the relationship curve and an algorithm based on previous data correlating with cardiac tamponade syndrome.

17. The system of claim 16, wherein the probe is configured to be positioned on an outer surface of the left or right ventricular outflow tract such that the probe measures one or both of the velocity or flow of blood through the left or right ventricular outflow tract, respectively.

18. The system of claim 16, wherein: the balloon is a pressure sensing balloon; and the processing device is further configured to: monitor a pressure measured by the balloon and a volume of fluid injected into the balloon; and generate a relationship curve between the pressure measured by the balloon and the volume of fluid injected into the balloon over time.

19. The system of claim 16, wherein the processing device is further configured to: measure the volume of the balloon; and generate a relationship curve between the volume of the balloon and a variation of cardiac output over time.

20. The system of claim 16, wherein the processing device is configured to calculate the blood flow through the left or right ventricular outflow tract by multiplying a velocity of blood flow, as determined by the probe, by a cross sectional area of the left or right ventricular outflow tract.

Description

[0125] The invention is illustrated in the attached figures, in which

[0126] FIG. 1 shows the heart contained within the pericardial sac, with arrows demonstrating the pressure exerted on the heart during tamponade

[0127] FIG. 2 also shows the heart contained within the pericardial sac. Compression of the heart following blood collection within the sac can be seen.

[0128] FIG. 3 is a diagram of one embodiment of the present invention. A balloon is inserted into the pericardial sac and injected with fluid, whilst a Doppler probe is suitably placed to monitor left or right ventricular outflow.

[0129] FIG. 4 is a diagram of the heart with major vessels labelled. The two preferred positions of the Doppler probe are indicated (on the aorta or on the pulmonary artery bifurcation).

PREFERRED STATEMENTS OF THE INVENTION INCLUDE

[0130] 1 A system for assessing the extent of cardiac tamponade in a patient, comprising: [0131] A Doppler probe capable of detecting velocity and/or flow of blood in either the left or right ventricular outflow tract; [0132] a balloon suitable for insertion and inflation in the pericardial space, mediastinal space, behind the sternum, or behind the heart; and [0133] a processing device communicatively coupled to the probe and optionally also the balloon

[0134] wherein the processing device is configured for determination of blood flow through the left or right ventricular outflow tract, such that the system gives an indication of the extent of potential tamponade in the patient based on the relationship between the volume of inflation of the pericardial balloon and the blood flow through the left or right outflow tract.

[0135] 2 The system of statement 1 wherein the balloon is a pressure-sensing balloon.

[0136] 3 The system of any of statements 1-2 wherein the balloon is configured to provide even pressure over the heart when inflated.

[0137] 4 The system of any of statements 1-3 wherein the balloon is configured to occupy some of the pericardial space, mediastinal space, the space behind the sternum, or the space behind the heart when inflated, limiting space for the heart and thus challenging the space available to the heart to relax and therefore determine whether the heart is at risk of developing tamponade.

[0138] 5 The system of any of statements 1-4 further comprising housing compartment(s) for the probe and/or balloon, wherein said housing compartment(s) facilitate removal and/or insertion of the balloon into the chest, by providing a delivery pathway into the chest.

[0139] 6 The system of statement 2 wherein the processing device is additionally configured to monitor the pressure sensed by the balloon and the volume of fluid injected into the balloon, and optionally to generate a pressure-volume curve over time.

[0140] 7 The system of any preceding statements wherein the diameter of the left or right ventricular outflow tract is used to calculate flow from the measured blood velocity.

[0141] 8 A balloon suitable for placement in the pericardial space, mediastinal space, behind the sternum, or behind the heart, configured to provide even pressure across the heart when inflated, and with a volume variable from 10 ml to 250 ml.

[0142] 9 A method for detecting cardiac tamponade comprising

[0143] (1) inflating a balloon located in the pericardial space, mediastinal space, behind the sternum, or behind the heart;

[0144] (2) measuring the velocity and/or flow of blood through the left or right ventricular outflow tract, suitably using a Doppler probe, wherein the probe is communicatively coupled to a processor,

[0145] (3) wherein the processor is configured for calculation of blood flow through the left or right ventricular outflow tract

[0146] such that the system gives an indication of the extent of potential tamponade in the patient based on the relationship between the volume of inflation of the balloon and the blood flow through the left or right ventricular outflow tract.

[0147] 10 A method for diagnosing cardiac tamponade comprising

[0148] (1) inflating a balloon located in the pericardial space, mediastinal space, behind the sternum, or behind the heart;

[0149] (2) measuring the velocity and/or flow of blood through the left or right ventricular outflow tract, suitably using a Doppler probe, wherein the probe is communicatively coupled to a processor,

[0150] (3) wherein the processor is configured for calculation of blood flow through the left or right ventricular outflow tract

[0151] such that the system gives an indication of the extent of potential tamponade in the patient based on the relationship between the volume of inflation of the balloon and the blood flow through the left or right ventricular outflow tract; and optionally

[0152] treating cardiac tamponade in patients diagnosed with cardiac tamponade.