Abstract: A method of manufacturing a lead connector end of an implantable medical lead is disclosed herein. The method may include: provide a mold cavity including a feature and a longitudinal axis; place a ring contact in the mold cavity, engage the ring contact with the feature; fill the mold cavity with a mold material, the feature preventing displacement of the ring contact along the longitudinal axis; allow the mold material to cure; remove a resulting lead connector end from the mold cavity; and reduce an excessive diameter of the resulting lead connector end to a finished diameter.

Abstract: An implantable medical lead is disclosed herein. In one embodiment, the lead includes a body, at least one electrode and a lead connector end. The body includes a distal portion and a proximal portion. The at least one electrode is on the distal portion. The lead connector end is on the proximal portion and includes a pin contact and a retainer assembly. The pin contact is electrically coupled to the at least one electrode and proximally extends from the lead connector end. The retainer assembly retains the pin contact as part of the lead connector end and includes a collar and a cap. The cap is secured within the collar via an interference fit arrangement and includes a hole through which the pin contact extends.

Abstract: Methods and systems may identify a vector or a vector configuration, such as a combination of electrodes, for monitoring ischemia. The method may include: selecting a first combination of sensors as a first candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the first candidate; selecting a second combination of sensors as a second candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the second candidate; comparing the ST shifts for the first and second candidates; and identifying one of the first and second candidates for monitoring ischemia based on the comparison. A multi-electrode implantable cardiac device may include a controller configured to effectuate such functions.

Abstract: Techniques are provided for controlling the recording of intracardiac electrograms (IEGMs) within an implantable medical device such as a pacemaker, wherein the device is capable of recording different channels of IEGMs in response to different diagnostic triggers. Exemplary triggers include pacemaker-mediated tachycardia; atrial tachycardia, atrial fibrillation, ventricular tachycardia, etc. In one example, the device stores, for each diagnostic trigger, a physician selection of particular IEGMs to be recorded for subsequent review. Then, whenever a trigger is detected, the device senses and records only the particular IEGMs that had been selected by the physician for that particular trigger. The IEGMs are eventually transmitted to an external programmer for review. In this manner, the physician can specify particular IEGMs to be stored in response to particular diagnostic triggers, thereby providing considerable diagnostic flexibility, while also conserving memory.

Abstract: Diagnosing a patient's cardiac health through histogram analysis of thoracic impedance is described. Data values indicative of thoracic impedance are measured from a patient over a sample period that includes multiple respiratory cycles. The values are distributed across multiple bins of a histogram. A diagnostic value for use in diagnosing a patient's cardiac health is derived from values in one or more of the bins. As one example, a diagnostic value representing minimum thoracic impedance during the sample period can be derived from values in the lowest-valued bins. Diagnostic values can be computed for multiple sample periods in the same fashion. A trend analysis is performed on the diagnostic values to determine whether the patient's cardiac condition is improving or worsening. The trend may be presented in a graphical form to provide a visual tool for assessing the patient's condition over time.

Abstract: A universal cable connector for detachably connecting a stimulation lead to a system analyzer includes a nonconductive connector block for releasably receiving and holding fixed a proximate contact electrically in continuity with a distal electrode, a cable for selectively electrically interconnecting the proximate contact and the system analyzer, and a switch mechanism for selectively connecting electrically the system analyzer cable with the proximate contact thereby enabling the system analyzer to determine the efficacy of the chosen body tissue site. The connector block includes a nest region for receiving the proximal end of the lead and the switch mechanism includes a switch contact electrically engaged with the cable and movable between a first position disengaged from an associated and selected exposed proximate contact and a second position engaged with the proximate contact for electrically connecting the distal electrode to the system analyzer.

Abstract: A method and apparatus are provided for controlling interrogation of an implantable device such as a pacemaker, an implantable cardioverter, or a defibrillator utilizing an external device in a home environment. The method controls how frequently a patient can retrieve status information from the implantable device based on a time period elapsed since a last interrogation and a power level of a battery.

Abstract: An exemplary implantable device includes control logic to determine a base state atrio-ventricular delay (e.g., PV base or AV base) based on width of an atrial event (e.g., ?P or ?A) as measured during a patient base state and based on a value of a parameter ? that depends on the atrial event and control logic to determine an active state atrio-ventricular delay (e.g., PV active or AV active) based at least in part on a base state interval (e.g., DD base or AD base) measured during a patient base state and an active state interval (e.g., DD active or AD active) measured during a patient active state where such intervals extend from the end of a respective atrial event to the beginning of a respective ventricular QRS complex or a point within a respective ventricular QRS complex. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: A method of identifying a potential cause of pulmonary edema is provided. The method includes obtaining one or more impedance vectors between predetermined combinations of the electrodes positioned proximate the heart. At least one of the impedance vectors is representative of a thoracic fluid level. The method also includes applying a stimulation pulse to the heart and sensing cardiac signals of the heart that are representative of an electrophysiological response to the stimulation pulse. The method further includes monitoring the cardiac signals and at least one of the impedance vectors with respect to time to identify the potential cause of pulmonary edema.

Abstract: Implantable medical leads have reduced diameter while providing for optimized mechanical and electrical properties, by reducing the diameters of the conducting cables used within the leads for sensing and delivery of therapeutic electrical stimulation. In an embodiment, conducting filaments within a cable have oval cross-sectional areas. Suitably orienting the oval filaments increases the contact surface between adjacent filaments, broadly distributing the pressure between filaments and reducing fretting fatigue, while the oval cross-sectional area also increases conductivity. In an embodiment, non-conducting coatings around filaments within a cable, or around groups of filaments organized into cable-layers, reduce fretting fatigue. In an embodiment, the cross-sectional area of filaments decreases as the filaments are positioned at increasing radial distances from the center of the cable.

Abstract: An exemplary method includes providing left atrial pressure information, based at least in part on the information, determining a weight and, based at least in part on the weight, determining a threshold for use in intrathoracic impedance monitoring. Such an exemplary method may include comparing an intrathoracic impedance to the threshold, comparing an intrathoracic impedance change to the threshold, or comparing a product of intrathoracic impedance and time to the threshold. Various exemplary methods, devices, systems, etc., are disclosed.

Abstract: Techniques are provided for detecting stroke within a patient using an implantable medical device in conjunction with an external confirmation system. In one example, a preliminary detection of stroke is performed by a subcutaneous monitor based on an analysis of features of an electrocardiogram (ECG) sensed within the patient. Exemplary ECG features indicative of possible stroke include the onset of prominent U-waves, the onset of notched T-waves, and changes in ST segment duration or QT duration or dynamic trends in these parameters. The monitor transmits a signal indicative of possible stroke to a bedside monitor or other external system, which generates a stroke questionnaire for use in confirming the stroke. Family members or other caregivers input answers to the questionnaire into the external system, which confirms or disconfirms the stroke. Emergency personnel can be automatically notified.

Abstract: An implantable medical lead for active fixation to cardiac tissue is disclosed herein. The lead may include a lead body distal end, a tissue fixation helical anchor and a structure. The tissue fixation helical anchor may be coupled to the lead body distal end and include a distal tip. The structure may be coupled to the lead body distal end and include a structure distal end including a first radiopaque marker. The structure may be biased to project the structure distal end near the distal tip. When the tissue fixation helical anchor is progressively embedded in the cardiac tissue, the cardiac tissue progressively displaces the structure distal end proximally.

Abstract: An implantable cardiac electrotherapy lead is disclosed herein. The lead may include an electrode on a distal portion of the lead, a conductor extending proximally through the lead from the electrode, and a crimp connector coupling a distal end of the conductor to the electrode. The connector may include a body with an outer surface, an inner surface, proximal and distal ends, a cavity, and at least one splice opening. The inner surface defines the cavity, the proximal and distal ends respectively define proximal and distal openings leading to the cavity, and the at least one splice opening extends from the outer surface to the inner surface and is oriented generally transverse to an axis extending between the proximal and distal openings.

Abstract: An implantable, multi-chamber cardiac stimulation device and method automatically adjust inter-chamber stimulation delays whenever stimulation rate is changed according to a patient's metabolic need. Inter-chamber stimulation delays include inter-atrial delays, inter-ventricular delays, and atrio-ventricular delays. Inter-chamber stimulation delays are defined according to whether the event which triggers the start of the delay is an intrinsic sensed event or the delivery of a stimulation pulse. Adjustment to inter-chamber stimulation delays is made as a function of the stimulation rate changes. By providing automatically adjustable inter-chamber stimulation delays optimal synchronization of heart chamber contractions may be maintained at all stimulation rates.

Abstract: 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.

Abstract: An implantable medical device having a lead retention assembly is disclosed herein. In one embodiment, the lead retention assembly comprises at least two receptacles configured to receive a connective end of a respective electrical lead, a support member, a first side clamp configured to define a first port in conjunction with the support member, a second side clamp configured to define a second port in conjunction with the support member, and a fastener configured to urge both the first and second side clamps toward the support member upon actuation of the fastener.

Abstract: Systems and methods are provided for providing back-up or redundant defibrillation in case of a faulty defibrillation path or faulty defibrillation circuit element. In case a problem is detected with one or more active or enabled electrode paths, the system and method selects available redundant circuits for active use.

Abstract: A ventricular rate based on first candidate waveforms and second candidate waveforms within sensed ventricular waveforms is compared to an atrial rate. If the ventricular rate exceeds the atrial rate, the first candidate waveforms and second candidate waveforms are compared to a ventricular polarization complex template to obtain a first morphology indicator and a second morphology indicator. If a morphology match inconsistency is present, the amount by which the ventricular rate exceeds the atrial rate is compared to a threshold. If the threshold is exceeded, high-ventricular-rate therapy to the heart is inhibited. The ventricular polarization complex template may be a QRS-complex template, in which case a match inconsistency is present if each of the first candidate waveforms and the second candidate waveforms do not match the QRS-complex template.

Abstract: A method and apparatus are provided for controlling interrogation of an implantable device such as a pacemaker, an implantable cardioverter, or a defibrillator utilizing an external device in a home environment. The method controls how frequently a patient can retrieve status information from the implantable device based on a time period elapsed since a last interrogation and a power level of a battery.