A system and method have at least one implantable lead comprising a right ventricular (RV) electrode and one or more left ventricular (LV) electrodes, at least one processor, and a memory coupled to the at least one processor. The memory stores program instructions. The program instructions are executable by the at least one processor to determine a right ventricular to left ventricular (RV-LV) conduction time representative of a conduction time between a right ventricular (RV) paced event and one or more responsive left ventricular (LV) sensed events, determine a left ventricular to right ventricular (LV-RV) conduction time representative of a conduction time between one or more LV paced event and an RV sensed events, calculate a relation between the RV-LV conduction time and the LV-RV conduction time, and set a pacing mode of an implantable medical device to one of i) a biventricular (BiV) pacing mode and ii) an LV only pacing mode based on the relation between the RV-LV conduction time and the LV-RV conduction time.

An apparatus comprises a stimulus circuit, a recharge circuit, a switch circuit, and a control circuit. The stimulus circuit provides electrical cardiac pacing stimulation to multiple combinations of a plurality of electrodes, and the electrical stimulation is selectively applied at the first electrode of the electrode combinations. The recharge circuit includes a recharge capacitor electrically coupled to the second electrode of the electrode combinations, and the switch circuit selectively enables electrode combinations for electrical coupling to the stimulus circuit and the recharge circuit. The control circuit includes a pacing activation sub-circuit that selectively initiates delivery of the electrical stimulation using multiple electrode combinations, and enables simultaneous delivery of pacing recharge energy from the recharge capacitor to the second electrode of multiple electrode combinations.

Systems and methods are provided for detecting arrhythmias in cardiac activity is provided. The systems and methods include measuring conduction delays between an atria (A) and multiple left ventricular (LV) electrodes to obtain multiple intrinsic A/LV intervals, measuring conduction delays between a right ventricular (RV) and the multiple LV electrodes to obtain multiple intrinsic VV intervals. The systems and methods include calculating a first atrial ventricular (AV) delay based on at least one of the intrinsic A/LV intervals, and calculating a second AV delay based on at least one of the intrinsic VV intervals. The systems and methods include selecting a biventricular (BiV) pacing mode or an LV only pacing mode based on a relation between the first and second AV delays, and delivering a pacing therapy based on the selecting operation.

The disclosure describes capturing the cardiac tissue using current steering techniques with a multi-pole cardiac lead implanted near the cardiac tissue. The techniques may include current-controlled sources in an IMD to provide current regulation to the pacing pulses allowing direct stimulation through multiple electrode contacts with known current delivery to the tissue. This current steering technique may use a delivery current source coupled to a delivery electrode and a receiving current source coupled to a receiving electrode to steer the current to the desired tissue to be stimulated. In some examples, different electrode pairs may be paced sequentially or together. In other examples, two or more electrodes may be considered the “delivery electrodes” and two or more electrodes may be considered the “receiving electrodes.” In some examples a current-controlled source in the IMD may be implemented using a source degeneration circuit.

There is provided a catheter for assessing cardiac function, the catheter comprising an elongate shaft extending from a proximal end to a distal end, where the shaft comprises a lumen for a guidewire and/or a saline flush. The catheter further comprises at least one electrode disposed on the shaft for sensing electrical signals in a bipolar or unipolar fashion and applying pacing to a patient's heart, at least one sensor disposed on the shaft for detecting an event relating to the rapid increase in the rate of pressure increase within the left ventricle of a patient; and communication means configured to transmit data received from the electrode(s) and the sensor(s).

Systems and methods are provided for detecting arrhythmias in cardiac activity is provided. The systems and methods include measuring conduction delays between an atria (A) and multiple left ventricular (LV) electrodes to obtain multiple intrinsic A/LV intervals, measuring conduction delays between a right ventricular (RV) and the multiple LV electrodes to obtain multiple intrinsic VV intervals. The systems and methods include calculating a first atrial ventricular (AV) delay based on at least one of the intrinsic A/LV intervals, and calculating a second AV delay based on at least one of the intrinsic VV intervals. The systems and methods include selecting a biventricular (BiV) pacing mode or an LV only pacing mode based on a relation between the first and second AV delays, and delivering a pacing therapy based on the selecting operation.

Approaches to rank potential left ventricular (LV) pacing vectors are described. Early elimination tests are performed to determine the viability of LV cathode electrodes. Some LV cathodes are eliminated from further testing based on the early elimination tests. LV cathodes identified as viable cathodes are tested further. Viable LV cathode electrodes are tested for hemodynamic efficacy. Cardiac capture and phrenic nerve activation thresholds are then measured for potential LV pacing vectors comprising a viable LV cathode electrode and an anode electrode. The potential LV pacing vectors are ranked based on one or more of the hemodynamic efficacy of the LV cathodes, the cardiac capture thresholds, and the phrenic nerve activation thresholds.

A method for selecting an implantation position of a pacing electrode of a pacing lead within an anatomical region of a body, comprising measuring values of at least one parameter of an anatomical region surrounding the pacing lead in at least one location. The method also comprises delivering an electric field to a tissue of the anatomical region, and measuring values of at least one parameter of the tissue surrounding the pacing lead in the at least one location after said delivering. The method further comprises determining changes in said measured values before and after said delivering and selecting an implantation position for the pacing electrode based on said determined changes.

Systems and methods for monitoring and treating patients with heart failure (HF) are discussed. The system may sense cardiac signals, and receives information about patient physiological or functional conditions. A stimulation parameter table that includes recommended values of atrioventricular delay (AVD) or other timing parameters maybe created at a multitude of patient physiological or functional conditions. The system may periodically reassess patient physiological or functional conditions. A therapy programmer circuit may dynamically switch between left ventricular-only pacing and biventricular pacing, or switch between single site pacing and multisite pacing based on the patient condition. The therapy programmer circuit may adjust AVD and other timing parameters using the cardiac signal input and the stored stimulation parameter table. A HF therapy may be delivered according to the determined stimulation site, stimulation mode, and the stimulation timing.

Methods, systems, and devices that are used for improving cardiac resynchronization therapy (CRT) are described herein. Such a method can include, for each set of pacing parameters, of a plurality of sets of pacing parameters, performing CRT using a set of pacing parameters and simultaneously therewith sensing a plurality of intracardiac electrograms (IEGMs) using different combinations of implanted electrodes. Additionally, for each set of pacing parameters, of the plurality of sets of pacing parameters, the method includes producing a respective reconstructed multi-lead surface electrocardiogram (ECG) based on the plurality of IEGMs that were sensed while CRT was performed using the set of pacing parameters. The method also includes analyzing the reconstructed multi-lead surface ECGs that were produced for the plurality of sets of pacing parameters, and based on results thereof, identifying a set of pacing parameters to be use for further CRT.