Mediwave Star Technology Inc.

University of North Carolina at Greensboro

Duke University

Joseph M Starobin

Yuri B Chernyak

Vivek Varadarajan

Wanda Krassowska Neu

Salim F Idriss

A method of determining the susceptibility to ventricular arrhythmias in a subject, the method including determining a reserve of refractoriness (RoR) and a reserve of memory (RoM) and combining the reserve of refractoriness (RoR) and the reserve of memory (RoM) to produce a metric of stability-of-propagation reserve (SoPR) in the subject, a higher value of SoPR indicating lower susceptibility to ventricular arrhythmias in the subject. Systems and apparatus for carrying out the method are also described.

Method and system for evaluating stability of cardiac propagation reserve

The present invention provides a method of stimulating an excitable tissue (e.g., in vitro, in vivo) with a primary electrical stimulus through a primary electrode at a primary stimulation frequency, to produce a propagating action potential in the excitable tissue. The invention is carried out by concurrently stimulating the excitable tissue with a secondary electrical stimulus through at least one secondary electrode at a secondary stimulation frequency. The primary and secondary stimulation frequencies are preferably different from one another. The secondary electrical stimulus preferably has an amplitude not more than one third that of the primary electrical stimulus. Preferably, propagation of the action potential in the excitable tissue is enhanced (e.g., when propagation of action potentials in the tissue is otherwise unstable, partially blocked, or fully blocked). Apparatus for carrying out the method is also described.

Method and system of stimulation of nerve tissue with a sequence of spatially distributed resonant sub-threshold electrical stimuli

A method of assessing the cardiac arrhythmia risk in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. In one embodiment, the method comprises the steps of: (a) collecting at least one QT and RR interval data set from the subject; (b) separating fluctuations from slow trends in said at least one QT and RR interval data set; (c) comparing said QT and RR fluctuations to one another and (d) generating from the comparison of step (c) partial measures of risk of cardiac arrhythmia in said subject. A greater difference between QT and RR fluctuations indicates greater risk of cardiac arrhythmia in said subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

Method and system for evaluating arrhythmia risk with QT-RR interval data sets

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first RR-interval data set from said subject during a stage of gradually increasing heart rate up to a predetermined heart rate of at least 130 beats per minute; (b) collecting a second RR-interval data set from said subject during a stage of gradually decreasing heart rate; (c) comparing said first RR-interval data set to said second RR-interval data set to determine the difference between said data sets; and (d) generating from said comparison of step (c) a measure of cardiac ischemia during stimulation in said subject, wherein a greater difference between said first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in said subject.

Method and system for evaluating cardiac ischemia with an exercise protocol

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load); (c) comparing the first RR-interval data set to the second RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject. Heart rate is gradually increased and gradually decreased in response to actual heart rate date collected from concurrent monitoring of the subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

Method and system for evaluating cardiac ischemia with heart rate feedback

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first QT- and RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second QT- and RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load); (c) comparing the first QT- and RR-interval data set to the second QT- and RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

Method and system for evaluating cardiac ischemia

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load); (c) comparing the first RR-interval data set to the second RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject. The data sets may be collected by any suitable method or device, including pulse monitoring and blood pressure monitoring.

Method and system for evaluating cardiac ischemia with RR-interval data sets and pulse or blood pressure monitoring

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load); (c) comparing the first RR-interval data set to the second RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

Method and system for evaluating cardiac ischemia with RR-interval data sets

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load); (c) comparing the first RR-interval data set to the second RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject. The data sets are collected with a plurality of separate electrodes indicative of different regions of the heart so that the generating step can include locating the region of greatest ischemia by comparing the amount of ischemia indicated in each region.

Method and system for evaluating and locating cardiac ischemia

A method of assessing cardiac ischemia in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load, or a stage of rest following an abrupt stop of exercise in a patient with coronary artery disease); (c) comparing the first RR-interval data set to the second RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.

Method and system for evaluating cardiac ischemia with an abrupt stop exercise protocol

A method of assessing cardiac ischemia in a subject to provide a measure of cardiovascular health in that subject is described herein. The method comprises the steps of: (a) collecting a first QT- and RR-interval data set from the subject during a stage of gradually increasing heart rate (e.g., a stage of gradually increasing exercise load); (b) collecting a second QT- and RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., a stage of gradually decreasing exercise load); (c) comparing the first QT- and RR-interval data set to the second QT- and RR-interval data set to determine the difference between the data sets; and (d) generating from the comparison of step (c) a measure of cardiac ischemia during exercise in the subject. A greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiovascular health in the subject. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize rapid transients due to autonomic nervous system and hormonal control on the data sets.

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Greensboro, NC, United States of America

Joseph M Starobin