124 results about "Cardiac ischemia" patented technology

A method for monitoring the progression of the hemodynamic status of a patient by tracking autonomic tone. For example, the method may be applied to patients suffering from heart failure, diabetic neuropathy, cardiac ischemia, sleep apnea and hypertension. An implantable or other ambulatory monitor senses a pulse amplitude signal such as a vascular plethysmography signal. Variations of the signal amplitude on a scale greater than the heartbeat to heartbeat scale are indicative of variations in autonomic tone. A significant reduction in pulse amplitude and pulse amplitude variability are indicative of a heart failure exacerbation or other disease state change. This information may be used to warn the patient or healthcare providers of changes in the patient's condition warranting attention.

The present invention provides novel nucleoside and nucleotide derivatives that are useful agonists or antagonists of P1 or P2 receptors. For example, the present invention provides a compound of formula A-M, wherein A is modified adenine or uracil and M is a constrained cycloalkyl group. The adenine or uracil is bonded to the constrained cycloakyl group. The compounds of the present invention are useful in the treatment or prevention of various diseases including airway diseases (through A2B, A3, P2Y2 receptors), cancer (through A3, P2 receptors), cardiac arrhythmias (through A1 receptors), cardiac ischemia (through A1, A3 receptors), epilepsy (through A1, P2X receptors), and Huntington's Disease (through A2A receptors).

Systems and techniques are provided for controlling vagus nerve stimulation (VNS) delivered by an implantable medical device for mitigating heart failure in a patient. In one mode, VNS therapy is set to levels just below a heart rate reduction threshold so as to deliver VNS near the highest stimulation levels that can be achieved without reducing patient heart rate. In this manner, a maximum level of heart failure mitigation can be achieved via VNS therapy without incurring the potentially adverse consequences of inducing bradycardia within the patient. In another mode, VNS therapy is instead controlled to deliver VNS above the threshold so as to mitigate heart failure while also selectively reducing heart rate, as may be appropriate in patients susceptible to cardiac ischemia. A controlled heart rate reduction curve may additionally or alternatively be determined for use in achieving target amounts of heart rate reduction.

Techniques are described for detecting and distinguishing among ischemia, hypoglycemia or hyperglycemia based on intracardiac electrogram (IEGM) signals. In one technique, these conditions are detected and distinguished based on an analysis of: the interval between the QRS complex and the peak of a T-wave (QTmax), the interval between the QRS complex and the end of a T-wave (QTend), alone or in combination with a change in ST segment elevation. By exploiting QTmax and QTend in combination with ST segment elevation, changes in ST segment elevation caused by hypo / hyperglycemia can be properly distinguished from changes caused by cardiac ischemia. In another technique, hyperglycemia and hypoglycemia are predicted, detected and / or distinguished from one another based on an analysis of the amplitudes of P-waves, QRS-complexes and T-waves within the IEGM. Appropriate warning signals are delivered and therapy is automatically adjusted.

Techniques are described for detecting and distinguishing among ischemia, hypoglycemia or hyperglycemia based on intracardiac electrogram (IEGM) signals. In one technique, these conditions are detected and distinguished based on an analysis of: the interval between the QRS complex and the peak of a T-wave (QTmax), the interval between the QRS complex and the end of a T-wave (QTend), alone or in combination with a change in ST segment elevation. By exploiting QTmax and QTend in combination with ST segment elevation, changes in ST segment elevation caused by hypo / hyperglycemia can be properly distinguished from changes caused by cardiac ischemia. In another technique, hyperglycemia and hypoglycemia are predicted, detected and / or distinguished from one another based on an analysis of the amplitudes of P-waves, QRS-complexes and T-waves within the IEGM. Appropriate warning signals are delivered and therapy is automatically adjusted.

An implantable medical device in which an electrogram is recorded and analyzed in order to detect changes indicative of cardiac ischemia. Cardiac ischemia may be detected by recording an electrogram from a sensing channel of the device and comparing the recorded electrogram with a reference electrogram. If cardiac ischemia is detected, a cardiac drug such as a thrombolytic agent is delivered.

Techniques are described for detecting changes in posture; detecting cardiac ischemia while accounting for changes in posture; and delivering therapy or warning signals in response thereto using the implantable medical device. In one example, the device detects variations in the electrical cardiac signals indicative of a possible episode of cardiac ischemia. Changes in patient posture are detected as well using an accelerometer or similar device. Then, an episode of cardiac ischemia is detected based on the variations in the cardiac signals while distinguishing variations due to changes in posture. In another example, the device instead detects changes in posture based on transient changes in morphological features of electrical cardiac signals.

A patient monitor for determining a probability that a patient has acute cardiac ischemia including an input device connectable to a patient to acquire electrocardiogram (ECG) signals from the patient, an instrumentation amplifier connected to the input terminal to combine the signals and to generate at least one ECG lead, and an analysis module. The analysis module is operable to continuously read the ECG lead, to analyze a portion of the ECG lead for a period of time, and to calculate a probability that the patient has acute cardiac ischemia based at least in part on the analyzed portion of the ECG lead.

A cardiac pacemaker in which an electrogram is recorded from an evoked response sensing channel in order to detect changes indicative of cardiac ischemia. If such changes are detected, the maximum allowable pacing rate can be decreased for those pacing modes that allow the pacing rate to change with metabolic demand.

A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as left bundle branch block beats and normal sinus beats. The processor applies different ischemia tests to the two different beat types, and generates alert when it detects ischemia.

An implantable medical device in which an electrogram is recorded and analyzed in order to detect changes indicative of cardiac ischemia. Cardiac ischemia may be detected by recording an electrogram from a sensing channel of the device and comparing the recorded electrogram with a reference electrogram. If cardiac ischemia is detected, a cardiac drug such as a thrombolytic agent is delivered.

The present invention provides methods and pharmaceutical compositions for treating or preventing cardiac dysfunctions (e.g., cardiac hypertrophy, cardiac remodeling, or heart failure) in subjects who have or are likely to develop cardiomyopathies. Some of the methods are directed to therapeutic or prophylactic treatment of cardiac dysfunctions in subjects having undergone myocardial injuries such as cardiac ischemia / reperfusion or myocardial infarction. Typically, these methods comprising administering to the subjects a therapeutic composition comprising a compound which can specifically inhibit PAR1 mediated signaling or down-regulate the cellular level of PAR1.

Techniques are described for adaptively adjusting detection thresholds for use in detecting cardiac ischemia and other abnormal physiological conditions based on morphological parameters derived from intracardiac electrogram (IEGM) signals, impedance measurements, or other signals. In one example, where ST segment elevation is used to detect cardiac ischemia, default detection thresholds are determined in advance from an examination of variations in ST segment elevations occurring within a population of patients. Thereafter, an individual pacemaker or other implantable medical device uses the default thresholds during an initial learning period to detect ischemia within the patient in which the device is implanted. During the initial learning period, the pacemaker also collects data representative of the range of variation in ST segment elevations occurring within the patient. The pacemaker then adaptively adjusts the thresholds based on the range of variation so as to improve detection specificity within the patient.

Pattern classification techniques are provided for use with an implantable medical device for detecting cardiac ischemia substantially in real-time. Values representative of morphological features of electrical cardiac signals are detected by the implantable medical device. Then, a determination is made as to whether the patient is subject to an on-going episode of cardiac ischemia by applying the values to a pattern classifier configured to identify patterns representative of cardiac ischemia. In one example, the determination is made substantially in real-time by the device itself based on the IEGM signals it detects. In other examples, the IEGM signals are relayed promptly to a bedside monitor or other external device, which analyzes the signals using the pattern classifier to detect ischemia. Therapy may be applied in response to cardiac ischemia. For example, if the implanted device is equipped with a drug pump, appropriate medications may be administered such as anti-thrombolytics.

A technique is provided for detecting episodes of cardiac ischemia based on an examination of post-T-wave signal segments. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF so that a warning may be delivered to the patient. The warning preferably includes both a perceptible electrical notification signal applied directly to subcutaneous tissue and a warning signal delivered via short range telemetry to a handheld warning device external to the patient. In one example, the onset of cardiac ischemia is identified by detecting a sharp falling edge within post-T-wave signals by filtering the signals using a high-pass filter having a cutoff frequency of at least 1 Hz. The total amount of energy in the filtered signal is calculated and compared against various thresholds.

A technique is provided for detecting episodes of cardiac ischemia based on an examination of the total energy of T-waves. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF. Briefly, the technique integrates internal electrical cardiac signals occurring during T-waves and then compares the result against a running average. If the result exceeds the average by some predetermined amount, ischemia is thereby detected and a warning signal is provided to the patient. The maximum slope of the T-wave is also exploited. Techniques are also set forth herein for reliably detecting T-waves, which help prevent P-waves from being misinterpreted as T-waves on unipolar sensing channels. The T-wave detection technique may be used in conjunction with ischemia detection or for other purposes.

A therapeutic method for treating ischemic or vascular disorders by administering an agent capable of inhibiting human delta-like ligand 4 (Dll4) activity to a subject in need thereof. In one embodiment, the agent is an anti-Dll4 antibody or antibody fragment capable of inhibiting the binding of Dll4 to a Notch receptor. The method of the invention is useful for treating eye disorders such as ischemic retinopathy, diabetic retinopathy, age related macular degeneration, corneal neovascularization, neovascular glaucoma, or retinopathy of prematurity. The method is also useful or treating ischemic or vascular disorders such as ischemic injury, cerebral ischemia, cardiac ischemia, ischemic conditions affecting the limbs and other organs or tissues, arteriovenous malformations, wound healing, organ or tissue transplantation, placental insufficiency, arterial narrowing and occlusion, atherosclerosis, and systemic or pulmonary hypertension.

A method of assessing cardiac ischemia in a subject to provide a measure of cardiovascular health in that subject is described. In general, 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; (b) collecting a second RR-interval data set from the subject during a stage of gradually decreasing heart rate (e.g., after an abrupt stop in exercise; during a stage of gradually decreasing exercise load; etc.); (c) separating fluctuations from a slow trend in the first RR-interval data set; (d) separating fluctuations from a slow trend in the second RR-interval data set; (e) comparing the fluctuations of the first RR-interval data set to the fluctuations of the second RR-interval data set to determine a difference between the fluctuation data sets; and (f) generating from the comparison of step (e) a measure of cardiac ischemia during stimulation in the subject, wherein a greater difference between the first and second data sets indicates greater cardiac ischemia and lesser cardiac or cardiovascular health in the subject.

Heart-monitoring systems, apparatus, and methods adapted to detect CS, CI and / or MI. In one embodiment, a system comprising at least two first-tier sensors capable of measuring and converting into signals at least two aspects related to cardiac function, at least one second-tier sensor that is also a first-tier sensor, at least one signal processor capable of transmitting a first-tier and second-tier trigger signal when coronary syndrome, cardiac ischemia or myocardial infarction has been detected, at least one communication device capable of communicating, at least one control element adapted to produce a first-tier and second-tier trigger signal when at least one first-tier sensor exceeds its threshold signal level, to exclude the signal from the first-tier sensor that exceeded its threshold and lower at least one threshold of the at least one first-tier sensor is provided.

Disclosed are (N)-methanocarba adenine nucleosides, e.g., of formula (I) as highly potent A3 adenosine receptor agonists, pharmaceutical compositions comprising such nucleosides, and a method of use of these nucleosides, wherein R1-R6 are as defined in the specification. These nucleosides exhibit similar selectivities as agonists of the A3 versus the A1 receptor for both human and mouse adenosine receptors, and are contemplated for use in the treatment a number of diseases, for example, inflammation, cardiac ischemia, stroke, asthma, diabetes, and cardiac arrhythmias.

Disclosed are methods of imaging a site in a heart of a subject to detect cardiovascular disease that involve stressing a subject, administering to the stressed subject an effective amount of a radionuclide-labeled chelator-glucose analog conjugate, and imaging the heart of the subject by detecting a signal generated by the conjugate in the heart of the subject. Also disclosed are methods of imaging a peripheral blood vessel in a subject by using a detectable amount of a radionuclide-labeled chelator-glucose analog conjugate. Also disclosed are methods of distinguishing a false positive nuclear cardiology scan from a true positive nuclear cardiology scan, methods of diagnosing congestive heart failure or cardiac ischemia that involve imaging a subject that has been administered a radionuclide-labeled chelator-glucose analog conjugate, and methods to distinguish viable from nonviable myocardium.

Disclosed are A3 adenosine receptor antagonists and / or partial agonists of formula (I): wherein R1 to R5 are as described herein, as well as pharmaceutical compositions thereof and methods of use thereof. The antagonists or partial agonists find use in treating a number of diseases including cancer, glaucoma, inflammatory diseases, asthma, stroke, myocardial infarction, allergic reactions, rhinitis, poison ivy induced responses, urticaria, scleroderma, arthritis, brain arteriole diameter constriction, bronchoconstriction, and myocardial ischemia, as well as in preventing cardiac ischemia. Also disclosed are radiolabeled compounds of formula (I) and the use thereof in diagnostic imaging of tissues and organs.

A technique is provided for detecting episodes of cardiac ischemia based on an examination of the total energy of T-waves. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF. Briefly, the technique integrates internal electrical cardiac signals occurring during T-waves and then compares the result against a running average. If the result exceeds the average by some predetermined amount, ischemia is thereby detected and a warning signal is provided to the patient. The maximum slope of the T-wave is also exploited. Techniques are also set forth herein for reliably detecting T-waves, which help prevent P-waves from being misinterpreted as T-waves on unipolar sensing channels. The T-wave detection technique may be used in conjunction with ischemia detection or for other purposes.

A system and method for determining a patient's degree of cardiac vascular blockage or, equivalently, a patient's risk of cardiac ischemia, based on the time interval between the onset of exercise activity and the onset of an episode of cardiac ischemia. In one embodiment, an implantable cardiac device may obtain an EGM and possibly other measures of patient physiologic activity. These measures are used to determine when the patient has initiated exercise activity. Analysis of the EGM then detects an elevated or depressed ST segment, which typically indicates an episode of cardiac ischemia. The time interval between the onset of exercise and the onset of ischemia is a metric reflecting the patient's degree of vascular blockage or, equivalently, the patient's risk of ischemia. Other metrics may be derived, such as a substantially workload-level invariant measure determined as the product of the exercise workload level and the ischemia onset time interval.

Compositions of the invention, including compounds that bind to a receptor for a glucagon-like peptide-1, an incretin, a glucagon-like peptide-1 (GLP-1), an exendin, or an agonist, an analog (preferably an agonist analog), a derivative, or a variant of any of aforementioned compounds, are used in the prevention and treatment of arrhythmias associated with cardiac ischemia, cardiac ischemia-perfusion and / or congestive heart failure. The invention relates to both the method and compositions for such treatment.

The invention is directed to tricyclic benzodiazepines useful as vasopressin receptor antagonists for treating conditions involving increased vascular resistance and cardiac insufficiency. Pharmaceutical compositions comprising tricyclic benzodiazepines of the present invention and methods of treating conditions such as hypertension, congestive heart failure, cardiac insufficiency, coronary vasospasm, cardiac ischemia, liver cirrhosis, renal vasospasm, renal failure, cerebral edema and ischemia, stroke, thrombosis, or water retention are also disclosed.

The present invention relates to a novel sustained release formulation with gastric retention properties comprising tedisamil or a pharmaceutically acceptable salt thereof and the use of this formulation in the prevention and treatment of atrial fibrillation, atrial flutter and cardiac ischemia.

Exemplary systems, devices, and methods for considering cardiac ischemia in electrode selection are described. One method determines whether an electrode of a multiple-electrode lead is proximate a region of cardiac ischemia or infarct. The method also paces through a different electrode of the multiple-electrode lead in an instance where the electrode is determined to be proximate the region.

Disclosed are (N)-methanocarba adenine nucleosides of formulas (I)-(V), for example, of formula (V):as highly potent A3 adenosine receptor agonists, pharmaceutical compositions comprising such nucleosides, and a method of use of these nucleosides, wherein R1-R6 are as defined in the specification. These nucleosides exhibit similar selectivities as agonists of the A3 versus the A1 receptor for both human and mouse adenosine receptors, and are contemplated for use in the treatment a number of diseases, for example, inflammation, cardiac ischemia, stroke, asthma, diabetes, and cardiac arrhythmias.

Integrin-linked kinase (ILK) and Akt / protein kinase B (PKB) are important mediators of signaling in cardiomyocytes and can both prevent damage and promote healing associated with ischemic injury to the heart. Thus, the present invention provides for methods of screening for agents that increase the expression of ILK and / or Akt / PKB. Methods of treatment based on such agents are also provided.