Methods, devices and program products are provided for managing a pacing therapy using an implantable medical device (IMD). The methods, devices and program products sense cardiac activity (CA) signals at electrodes located proximate to multiple left ventricular (LV) sites and a right ventricular (RV) site of the heart and utilizing one or more processors to measure activation times between the multiple LV sites and the RV site based on the CA signals. The processors program an order of activation for the multiple LV sites based on the activation times and identify an RV activation time and a septum activation time based on the CA signals. The processors calculate a septum to RV activation time (SRAT) based on the RV and septum activation times and program an AV.sub.SRAT delay based on the SRAT.

Systems, methods, and devices are described herein for evaluation, adjustment, and delivery of adaptive cardiac therapy. The systems, methods, and devices may utilize electrical heterogeneity information to determine and/or select one or more pacing settings and pacing type or configurations for a plurality of different heart rates. The adaptive cardiac therapy may deliver cardiac therapy at selected pacing settings such as, for example, A-V and/or V-V intervals, according to a presently measured heart rate and switch between left ventricular-only or biventricular cardiac pacing therapy also according to the presently measured heart rate.

A method and apparatus for treatment of hypertension and heart failure by increasing vagal tone and secretion of endogenous atrial hormones by excitory pacing of the heart atria. Atrial pacing is done during the ventricular refractory period resulting in atrial contraction against closed AV valves, and atrial contraction rate that is higher than the ventricular contraction rate. Pacing results in the increased atrial wall stress. An implantable device is used to monitor ECG and pace the atria in a nonphysiologic manner.

Systems and methods involve an intrathoracic cardiac stimulation device operable to provide autonomous cardiac sensing and energy delivery. The cardiac stimulation device includes a housing configured for intrathoracic placement relative to a patient's heart. A fixation arrangement of the housing is configured to affix the housing at an implant location within cardiac tissue or cardiac vasculature. An electrode arrangement supported by the housing is configured to sense cardiac activity and deliver stimulation energy to the cardiac tissue or cardiac vasculature. Energy delivery circuitry in the housing is coupled to the electrode arrangement. Detection circuitry is provided in the housing and coupled to the electrode arrangement. Communications circuitry may optionally be supported by the housing. A controller in the housing coordinates delivery of energy to the cardiac tissue or cardiac vasculature in accordance with an energy delivery protocol appropriate for the implant location.

Described herein are implantable medical devices (IMDs), and methods for use therewith, that enable monitoring of impedance associated with a pathway (e.g., including a lead) used to selectively deliver stimulation pulses to patient tissue. A method involves measuring or storing a first voltage indicative of the energy stored on a reservoir capacitor (Cres) just prior to a stimulation pulse being delivered via the pathway, as well as measuring or storing a second voltage indicative of the energy stored on the Cres just after the stimulation pulse is delivered via the pathway. The method also includes monitoring the impedance associated with the pathway based on a difference between the first and second voltages, which may involve determining a count value indicative of how long it takes to discharge the first voltage to drop to the second voltage, wherein the count value is a surrogate of the impedance associated with the pathway.

An apparatus comprises a cardiac signal sensing circuit configured for coupling electrically to a plurality of electrodes and to sense intrinsic cardiac activation at three or more locations within a subject's body using the electrodes; a stimulus circuit configured for coupling to the plurality of electrodes; a signal processing circuit electrically coupled to the cardiac signal sensing circuit and configured to determine a baseline intrinsic activation vector according to the sensed intrinsic cardiac activation; and a control circuit electrically coupled to the cardiac signal sensing circuit and stimulus circuit and configured to: initiate delivery of electrical pacing therapy using initial pacing parameters determined according to the baseline intrinsic activation vector; initiate sensing of a paced activation vector; and adjust one or more pacing therapy parameters according to the paced activation vector.

In some examples, controlling delivery of CRT includes controlling an implantable medical device to deliver ventricular pacing according to a sequence of different values of a CRT parameter, and acquiring first and second electrograms from respective first and second electrode vectors. For each value of the CRT parameter, a value of a metric of comparison of a first activation interval between occurrences of a first fiducial of a cardiac cycle and a second fiducial of the cardiac cycle detected in the first electrogram to a second activation interval between occurrences of the first fiducial and the second fiducial detected in the second electrogram may be determined. A target value of the metric of comparison may be identified and an updated value of the CRT parameter determined based on the target value. The system then may control the IMD to deliver ventricular pacing at the updated value of the CRT parameter.

Systems and methods for monitoring and treating patients with heart failure are discussed. The system can store in a memory stimulation parameters, including stimulation timing parameters for a plurality of heart rate ranges. The system includes a plurality of timers with respective durations for the plurality of heart rate ranges. A stimulation control circuit can identify a target heart range in which a detected heart rate falls, and measure an atrioventricular (AV) conduction characteristic value in response to the timer for the target heart range being expired at the detected heart rate. The stimulation control circuit can update a stimulation parameter corresponding to the target heart rate range using the measured AV conduction characteristic. The updated stimulation parameter can be used in cardiac stimulation.

Systems and methods for monitoring and treating patients with heart failure are discussed. The system may receive patient atrioventricular (AV) conduction characteristic under different heart rates or patient conditions. Stimulation parameters including stimulation timing parameters may be stored in a memory. The system may include a stimulation control circuit configured to determine a parameter update schedule indicating a timing at which to update stimulation parameter using patient AV conduction characteristic, and dynamically update at least a portion of the stored set of stimulation parameters at the determined parameter update schedule. For a specified heart rate or heart rate range, a stimulation parameter may be selected from the set of the stimulation parameters for use during cardiac stimulation.

A pacemaker lead for cerclage pacing includes a lead fixing part including a fixing tip whose diameter becomes gradually smaller toward an end of a distal part thereof, a plurality of bipolar electrodes that come into close contact with heart muscle, in an outer circumference of the lead fixing part, and a guide wire insertion through hole through which a guide wire can be inserted thereinto, a lead body part configured to be extended to the lead fixing part, having a stylet insertion through hole formed therein, and a body fixing part formed in a bent shape so as to be fixed to an inner wall of the coronary sinus, and a stylet inserted into the stylet insertion through hole, enabling the pacemaker lead for cerclage pacing to be easily moved within the body of the patient.