30 results about "Ventricular filling" patented technology

Systems and methods for noninvasive assessment of cardiac tissue properties and cardiac parameters using ultrasound techniques are disclosed. Determinations of myocardial tissue stiffness, tension, strain, strain rate, and the like, may be used to assess myocardial contractility, myocardial ischemia and infarction, ventricular filling and atrial pressures, and diastolic functions. Non-invasive systems in which acoustic techniques, such as ultrasound, are employed to acquire data relating to intrinsic tissue displacements are disclosed. Non-invasive systems in which ultrasound techniques are used to acoustically stimulate or palpate target cardiac tissue, or induce a response at a cardiac tissue site that relates to cardiac tissue properties and / or cardiac parameters are also disclosed.

A method of evaluating ventricular performance of a heart employing sensors to measure a ventricular dimension signal and deriving indices of ventricular performance therefrom. Premature Shortening (PS) and Isovolumic Lengthening (IL) comprise two indices of ventricular performance determined from analysis of the left ventricular dimension signal during the transition from ventricular filling to ventricular ejection. Measured values of PS and IL are compared to other measured values or reference values to determine if ventricular performance has improved (or worsened). In some embodiments, the dimension sensors may comprise piezoelectric sonomicrometer crystals that operate as ultrasound transmitters and receivers. The sensors may be mounted in relation to a ventricle of the heart either temporarily or permanently, and may be configured either separately from or integrally with cardiac pacing leads.

The devices and method described herein allow for therapeutic damage to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff. For example, improving a diastolic heart function in a heart by creating at least one incision in cardiac muscle forming an interior heart wall of the interior chamber where the at least one incision extends into one or more layers of the interior heart wall without puncturing through the interior heart wall and the incision is sufficient to reduce a stiffness of the interior chamber to increase volume of the chamber and reduce diastolic filing pressure.

The devices and method described herein allow for therapeutic damage to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff.

Apparatus for diastole trimming including a controller for producing a diastole ending signal, and one or more leads connected to the controller, for carrying the signal to lead connections to a heart, characterized by the controller detecting when a left ventricle (LV) of the heart is mostly full, and producing the diastole ending signal such that the diastole duration is trimmed. Apparatus for diastole trimming including a controller for producing a diastole ending signal, and a connection to a pacemaker, characterized by the controller having decision rules for indicating to the pacemaker when to fire and end the diastole. A method of programming a pacemaker characterized by increasing cardiac output by trimming duration of diastole. A method for increasing cardiac output including producing a signal to trim diastole duration, thereby increasing heart rate (HR) and increasing a product of stroke volume (SV) times HR. Related apparatus and methods are also described.

A method of data management for optimizing the patient outcome from the provision of cardiac resynchronization therapy (CRT) is described. A regression equation is constructed using 3 data points on a plot of AV delay vs. HR. The x-axis consist of the three points consist of resting HR, HR at the optimal AV delay value during light exercise, and the upper tracking or paced HR. The y-values associated with the three points consist of the AV delay values computed using an equation for ventricular filling time and the optimally determined AV delay value. Also described is a process for determining the sensed to paced AV delay offset. The combined processes yield 4 (the three constant values in the polynomial regression equation Y=b2X2+b1X+a and the sensed to paced AV delay offset) which can be stored on the patient's pacemaker for determining dynamically the AV delay value which is physiologically fine-tuned for each patient from resting HR to the upper tracking or paced HR. In combination with visual observation and computer-assisted ranking of the dependent variables, a physician can utilize the resulting information to render decisions on the optimal choice of the programming biventricular pacemakers / ICDs and DDDR pacemakers for individual patients.

A system and method of determining hemodynamic parameters uses sensed ventricular blood pressure during a portion of ventricular pressure waveform following peak pressure. An estimated arterial diastolic pressure is based upon an amplitude of the sensed ventricular pressure corresponding to a time at which a first derivative of ventricular pressure as a function of time is at a minimum (dP / dtmin). Fill parameters such as isovolumetric relaxation constant, ventricular suction pressure, atrial kick pressure, and transvalve pressure gradient are derived from measured pressures representing minimum ventricular pressure, ventricular diastolic pressure, and diastasis pressure.

The devices and method described herein allow for therapeutic damage to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff.

The devices and method described herein allow for therapeutic damage to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff.

The devices and method described herein allow for therapeutic damage to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff.

An active implantable medical device such as a cardiac prosthesis for the treatment of a heart failure by controlled adjustment of the atrioventricular and interventricular delays. The device provides atrioventricular and / or biventricular stimulation, a sensor delivering at least one hemodynamic parameter correlated with time intervals representative of the succession of the systolic and diastolic phases, and circuits to adjust the AV delay and / or VV delay. The device determines (12) during one cardiac cycle several parameters such as the left ventricular pre-ejection interval LPEI, the left ventricular ejection time LVET, the diastolic filling time FT and the conduction time PR. The device compares (14, 18) these parameters with at least one predetermined criterion. If a condition is met, the device readjusts (16) the AV delay and / or VV delay to maximize the ventricular filling and ejection.

The devices and method described herein allow for therapeutic damage to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff.

A method of treating diastolic heart failure includes implanting a cardiac implant in a heart of a subject diagnosed as suffering from diastolic heart failure. A superior portion of a flexible tether of the cardiac implant is anchored to one or more left-atrial sites of one or more walls of the left atrium. An inferior portion of the flexible tether is anchored to a site of a wall of a mid third of the left ventricle, of a wall of an apical third of the left ventricle, and / or of a papillary muscle of the left ventricle. As a result, the flexible tether reduces a volume of the left atrium during at least a portion of ventricular diastole of each cardiac cycle, thereby enhancing ventricular filling. Other embodiments are also described.

A method and system are provided to analyze valve related timing and monitor heart failure. The method and system comprise collecting cardiac signals associated with an atrial chamber of interest; collecting dynamic impedance (DI) data along an atria-function focused (AFF) vector to form a DI data set, the DI data set including information corresponding to a mechanical function (MF) of a valve associated with the atrial chamber of interest; identifying, from the cardiac signals, an intra-atrial conduction timing (IACT) associated with the atrial chamber of interest; estimating an MF landmark at which the mechanical function of the valve occurs based on the DI data set; analyzing a timing delay between the MF landmark and the IACT; and adjusting a therapy, based on the timing delay, to encourage atrial contribution to ventricular filling.

An implantable medical device has an event detector that detects a predetermined cardiac event during a heart cycle of a subject. A reference time is assigned to this detected cardiac event. An onset detector detects the onset of ventricular filling of the heart during the heart cycle. The relative time of the detected filling onset is determined based on the assigned time reference. An increased risk of heart failure of the subject is automatically determined based on the determined relative time for the filling onset. Generally, a reduction in the relative time, as determined at different points in time, indicates an increased heart failure risk or the presence of a heart failure condition.