Abstract: An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.

Abstract: In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

Abstract: An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.

Abstract: Methods, systems, and devices for enhancing the efficiency and efficacy of energy delivery and tissue mapping. One system includes a treatment element having a plurality of electrodes and an energy generator that is configured to deliver electric energy pulses to the electrodes in a variety of patterns. For example, electrodes may be arranged in closely spaced pairs. The energy generator may deliver mapping energy to each electrode in each pair individually to map tissue and may deliver ablation energy to the electrodes in each pair together, such that each pair is treated like a single electrode, to deliver ablation energy, such as bipolar ablation energy between adjacent pairs. One system includes at least one concave electrode, the configuration of which concentrates the energy and drives it deeper into the tissue. One system includes neutral electrodes between active electrodes, the energy generator selectively coupling the neutral electrodes to alter the ablation pattern.

Abstract: Methods, systems, and devices for enhancing the efficiency and efficacy of energy delivery and tissue mapping. One system includes a treatment element having a plurality of electrodes and an energy generator that is configured to deliver electric energy pulses to the electrodes in a variety of patterns. For example, electrodes may be arranged in closely spaced pairs. The energy generator may deliver mapping energy to each electrode in each pair individually to map tissue and may deliver ablation energy to the electrodes in each pair together, such that each pair is treated like a single electrode, to deliver ablation energy, such as bipolar ablation energy between adjacent pairs. One system includes at least one concave electrode, the configuration of which concentrates the energy and drives it deeper into the tissue. One system includes neutral electrodes between active electrodes, the energy generator selectively coupling the neutral electrodes to alter the ablation pattern.

Abstract: In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

Abstract: In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

Abstract: An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.

Abstract: In some examples, a medical device system includes an electrode. The medical device system may include impedance measurement circuitry coupled to the electrode, the impedance measurement circuitry may be configured to generate an impedance signal indicating impedance proximate to the electrode. The medical device system may include processing circuitry that may be configured to identify a first component of the impedance signal. The first component of the impedance signal may be correlated to a cardiac event. The processing circuitry may be configured to determine that the cardiac event occurred based on the identification of the first component of the impedance signal.

Abstract: Methods, systems, and devices for enhancing the efficiency and efficacy of energy delivery and tissue mapping. One system includes a treatment element having a plurality of electrodes and an energy generator that is configured to deliver electric energy pulses to the electrodes in a variety of patterns. For example, electrodes may be arranged in closely spaced pairs. The energy generator may deliver mapping energy to each electrode in each pair individually to map tissue and may deliver ablation energy to the electrodes in each pair together, such that each pair is treated like a single electrode, to deliver ablation energy, such as bipolar ablation energy between adjacent pairs. One system includes at least one concave electrode, the configuration of which concentrates the energy and drives it deeper into the tissue. One system includes neutral electrodes between active electrodes, the energy generator selectively coupling the neutral electrodes to alter the ablation pattern.

Abstract: Implantable medical leads include a conductive interconnect within a high frequency shunt that dissipates high frequency current. The conductive interconnect provides an elasticity that allows a drive shaft to rotate and translate during implantation of the lead while the conductive interconnect maintains physical contact with the drive shaft and with a shunt electrode before, during, and after the implantation. The conductive interconnect may provide a low friction that presents a smooth rotation and translation of the drive shaft to provide an acceptable tactile feedback during implantation. The conductive interconnect also provides a high electrical conductivity so that a substantial amount of high frequency current flows through the conductive interconnect to the shunt electrode. The conductive interconnect may include a polymer filler that partially penetrates into the interstitial spaces of the conductive interconnect to assist in maintaining the physical integrity of the conductive interconnect.