65 results about "Left atrial pressure" patented technology

Apparatus and method for noninvasively determining cardiac performance parameters including 1) lengths of systolic time intervals, (2) contractility index, (3) pulse amplitude ratios while performing the Valsalva maneuver, (4) cardiac output index, and (5) a pulse wave velocity index. A catheter having at least one balloon is inserted into the esophagus and pressurized and positioned adjacent the aortic arch to sense aortic pressure. The effects of aortic pressure on the balloon are utilized to determine at least one of the cardiac performance parameters. The catheter may include a second balloon which is spaced from the aortic balloon a distance such that when the second balloon is in a position adjacent the left atrium to sense left atrial pressure the aortic balloon is in a position adjacent the aortic arch to sense aortic pressure, this distance being related to the distance between the left atrium and aortic arch in most adult persons.

Several unique intracardiac pressure vents, placement catheters, methods of placement and methods of treating heart failure are presented. The intracardiac pressure vents presented allow sufficient flow from the left atrium to the right atrium to relieve elevated left atrial pressure and resulting patient symptoms but also limit the amount of flow from the right atrium to the left atrium to minimize the potential for thrombus or other embolic material from entering the arterial circulation. In embodiments, the device comprises a core segment, an annular flange to engage one surface of the atrial septum and two other annular flanges to engage another surface of the atrial septum.

Several unique intracardiac pressure vents, placement catheters, methods of placement and methods of treating heart failure are presented. The intracardiac pressure vents presented allow sufficient flow from the left atrium to the right atrium to relieve elevated left atrial pressure and resulting patient symptoms but also limit the amount of flow from the right atrium to the left atrium to minimize the potential for thrombus or other embolic material from entering the arterial circulation. Retrievability during deployment is improved, in part, by providing at least one segment or portion of the device that is retained within the placement catheter while all other segments or portions of the device are deployed.

The present disclosure relates to devices and methods for implanting a prosthesis into a heart of a mammal, such as a person. The disclosure includes a prosthesis that acts as a pressure vent between the left and right atria of the heart. The disclosure also includes a mounting tool for mounting the prosthesis onto a loading tool, the loading tool useful for loading the prosthesis onto a device for delivering the prosthesis into the patient's heart. Control devices and methods for using these devices are also disclosed. The intracardiac pressure vents disclosed allow sufficient flow from the left atrium to the right atrium to relieve elevated left atrial pressure and resulting patient symptoms. The devices also limit the amount of flow from the right atrium to the left atrium to minimize the potential for thrombi or other embolic material from entering arterial circulation.

Disclosed are cardiac shunts and method of delivery, and in particular, to a shunt to reduce elevated left atrial pressure (LAP). The methods include forming a puncture hole between the left atrium and the coronary sinus, widening the puncture hole, and placing an expandable shunt within the widened puncture hole. A first catheter having a side-extending needle may be used to form a puncture into the left atrium. A second catheter extends along a guidewire and an expandable shunt with distal and proximal flanges is expelled therefrom into the puncture. The shunt defines a blood flow passage therethrough that permits shunting of blood from the left atrium to the coronary sinus when the LAP is elevated. The shunt is desirable formed of a super-elastic material and manipulated with control rods. The shunt defines a tilted flow tube that facilitates collapse into the catheter.

A device for regulating blood pressure between a patient's left atrium and right atrium comprises an hourglass-shaped stent comprising a neck region and first and second flared end regions, the neck region disposed between the first and second end regions and configured to engage the fossa ovalis of the patient's atrial septum; and a one-way tissue valve coupled to the first flared end region and configured to shunt blood from the left atrium to the right atrium when blood pressure in the left atrium exceeds blood pressure in the right atrium. The inventive device may include a biodegradable material that biodegrades to offset flow changes caused by tissue ingrowth. The inventive device may reduce left atrial pressure and left ventricular end diastolic pressure, and may increase cardiac output, increase ejection fraction, relieve pulmonary congestion, and lower pulmonary artery pressure, among other benefits.

The present disclosure relates to devices and methods for implanting a prosthesis into a heart of a mammal, such as a person. The disclosure includes a prosthesis that acts as a pressure vent between the left and right atria of the heart. The disclosure also includes a mounting tool for mounting the prosthesis onto a loading tool, the loading tool useful for loading the prosthesis onto a device for delivering the prosthesis into the patient's heart. Control devices and methods for using these devices are also disclosed. The intracardiac pressure vents disclosed allow sufficient flow from the left atrium to the right atrium to relieve elevated left atrial pressure and resulting patient symptoms. The devices also limit the amount of flow from the right atrium to the left atrium to minimize the potential for thrombi or other embolic material from entering arterial circulation.

Various techniques are provided for calibrating and estimating left atrial pressure (LAP) using an implantable medical device, based on impedance, admittance or conductance parameters measured within a patient. In one example, default conversion factors are exploited for converting the measured parameters to estimates of LAP. The default conversion factors are derived from populations of patients. In another example, a correlation between individual conversion factors is exploited to allow for more efficient calibration. In yet another example, differences in thoracic fluid states are exploited during calibration. In still yet another example, a multiple stage calibration procedure is described, wherein both invasive and noninvasive calibration techniques are exploited. In a still further example, a therapy control procedure is provided, which exploits day time and night time impedance / admittance measurements.

Techniques are provided for estimating left atrial pressure (LAP) or other cardiac performance parameters based on measured conduction delays. In particular, LAP is estimated based interventricular conduction delays. Predetermined conversion factors stored within the device are used to convert the various the conduction delays into LAP values or other appropriate cardiac performance parameters. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP or other cardiac performance parameters. Still further, techniques are described for estimating conduction delays based on impedance or admittance values and for tracking heart failure therefrom.