Abstract: An apparatus and method to discriminate cardiac events by sensing atrial and ventricular depolarizations having associated refractory periods thereafter. A fast ventricular rate is detected in response to the sensed ventricular depolarizations. Responsive to detecting the fast ventricular rate, at least one stimulus pulse is delivered to atrial tissue within the associated refractory period of the ventricle but outside of an associated refractory period of the stimulated atrial tissue. A ventricular response to the atrial tissue stimulus pulse is determined, and the cardiac event is discriminated based on the ventricular response to the atrial tissue stimulus pulse.

Abstract: Drug-delivery systems for local drug delivery to kidneys and associated systems and methods are disclosed herein. One aspect of the present technology is directed to drug-delivery systems that include a physiological sensor, an implantable medical device, and a control module configured to communicate with the physiological sensor and to control delivery of a drug in response to a physiological parameter measured by the physiological sensor. The implantable medical device can be configured to be surgically implanted in a patient with a delivery opening at or near a renal capsule of a kidney of the patient. Suitable drugs for local delivery to a kidney can include diuretics, aldosterone antagonists, vasodilators, renin inhibitors, and combinations thereof. In some embodiments, local drug delivery to a kidney can be used to treat hypertension, heart failure, or another condition associated with renal activity.

Abstract: Various techniques for delivering atrial pacing and supraventricular stimulation to achieve a desired ventricular rate and/or cardiac output are described. One example method described includes delivering a pacing signal configured to cause an atrial depolarization to a heart of a patient, wherein the atrial depolarization results in an associated refractory period during the cardiac cycle, and delivering a signal to a supraventricular portion of the heart of the patient subsequent to the atrial refractory period and during a ventricular refractory period of the cardiac cycle.

Abstract: An apparatus and method to discriminate cardiac events by sensing atrial and ventricular depolarizations having associated refractory periods thereafter. A fast ventricular rate is detected in response to the sensed ventricular depolarizations. Responsive to detecting the fast ventricular rate, at least one stimulus pulse is delivered to atrial tissue within the associated refractory period of the ventricle but outside of an associated refractory period of the stimulated atrial tissue. A ventricular response to the atrial tissue stimulus pulse is determined, and the cardiac event is discriminated based on the ventricular response to the atrial tissue stimulus pulse.

Abstract: An apparatus and method to discriminate cardiac events by sensing atrial and ventricular depolarizations having associated refractory periods thereafter. A fast ventricular rate is detected in response to the sensed ventricular depolarizations. Responsive to detecting the fast ventricular rate, at least one stimulus pulse is delivered to atrial tissue within the associated refractory period of the ventricle but outside of an associated refractory period of the stimulated atrial tissue. A ventricular response to the atrial tissue stimulus pulse is determined, and the cardiac event is discriminated based on the ventricular response to the atrial tissue stimulus pulse.

Abstract: Various techniques for delivering atrial pacing and supraventricular stimulation to achieve a desired ventricular rate and/or cardiac output are described. One example method described includes delivering a pacing signal configured to cause an atrial depolarization to a heart of a patient, wherein the atrial depolarization results in an associated refractory period during the cardiac cycle, and delivering a signal to a supraventricular portion of the heart of the patient subsequent to the atrial refractory period and during a ventricular refractory period of the cardiac cycle.

Abstract: A composition for implantation into cardiac tissue includes a biological pacemaker that, when implanted, expresses an effective amount of a mutated hyperpolarization-activated and cyclic nucleotide-gated (HCN) isoform to modify Ih when compared with wild-type HCN. Methods for implementing each of the biologocal pacemakers include implanting each of biologocal pacemakers into cardiac tissue.

Abstract: A method and apparatus for reducing a patient's heart rate or blood pressure. The apparatus provides stimulation to the patient's atrial and/or nodal tissue within the associated refractory period of the ventricle but outside of an associated refractory period of the stimulated atrial an/or nodal tissue, responsive to detecting an occurrence of a ventricular depolarization following a preceding atrial depolarization. The apparatus may define a time window following the ventricular depolarization, following the atrial depolarization or determined based upon the timing of both the atrial and ventricular depolarizations. The stimulus may be delivered during or on expiration of the defined time window. The duration of the time window may be pre-set or determined based upon measurements of the patient's refractory periods.

Abstract: A biological pacemaker composition for implantation into cardiac tissue includes an effective amount of interstitial cells of Cajal (ICC) to produce or conduct pacing stimuli and thereby modulate cardiac contraction. The biological pacemaker may be included as part of a heart pacing system that includes an implantable electric pacemaker for producing backup pacing stimuli if the at least one biological pacemaker is unable to modulate cardiac contraction at a predetermined pacing rate. Methods for preventing cardiac pacing or conduction dysfunction in a heart include implanting the biological pacemaker or the heart pacing system into the heart.

Abstract: A composition for implantation into cardiac tissue includes a biological pacemaker that, when implanted, expresses an effective amount of a mutated hyperpolarization-activated and cyclic nucleotide-gated (HCN) isoform to modify Ih when compared with wild-type HCN. Methods for implementing each of the biological pacemakers include implanting each of biological pacemakers into cardiac tissue.

Abstract: A biological pacemaker composition for implantation into cardiac tissue includes an effective amount of interstitial cells of Cajal (ICC) to produce or conduct pacing stimuli and thereby modulate cardiac contraction. The biological pacemaker may be included as part of a heart pacing system that includes an implantable electric pacemaker for producing backup pacing stimuli if the at least one biological pacemaker is unable to modulate cardiac contraction at a predetermined pacing rate. Methods for preventing cardiac pacing or conduction dysfunction in a heart include implanting the biological pacemaker or the heart pacing system into the heart.

Abstract: The present invention provides therapeutic methods which employ one or more identifiable types of mammalian stem cells, and/or their progenitor progeny cells, and/or their lineage-committed descendant cells, and/or their partially-differentiated offspring cells—with or without completely differentiated cells—to treat living mammalian subjects afflicted with a clinically recognized form of cardiopathology. The identifiable cell types include embryonic stem cells and their offspring cells; as well as the presently identified types of adult stem cells and their various offspring cells; and also include recently identified alternative cell types which have functional stem cell properties. Among the clinical forms of cardiopathology which can be efficaciously treated using the present therapeutic methods are myocardial infarction, myocarditis, heart failure, and cardiac dysrhythmia.

Abstract: The present invention provides genetically altered mammalian embryonic stem cells, their living descendent progeny having an altered genomic DNA, and therapeutic methods using these cells for improving cardiac function in a living subject after myocardial infarction. The genetically altered embryonic stem and progenitor cells may be maintained in-vitro as a stable cell line; and transplanted as active, mitotic cells to an infarcted area of the myocardial using any surgical procedure. After transplantation at a chosen anatomic site within the heart of the subject, these genetically altered cells will differentiate in-site, cause a regeneration of myocardocytes, and will effect a marked improvement in cardiac function for the subject.

Abstract: The present invention is a method for markedly improving cardiac function and repairing heart tissue in a living mammalian subject after the occurrence of a myocardial infarction. The method is a surgical technique which introduces and implants mammalian embryonic stem cells into the infarcted area of the myocardium. After implantation, the embryonic stem cells form stable grafts and survive indefinitely within the infarcted area of the heart in the living host. The demonstrated beneficial effects of the method include a decreased infarcted area and improved cardiac function as assessed by hemodynamic and echocardiographic measurements.