Devices and methods for detecting an event using a variable threshold. A patient monitoring system can receive physiologic information and compare the information to an onset threshold. When the onset threshold is exceeded, the system shifts to a reset threshold that is different than the onset threshold. When the reset threshold is crossed, the system shifts back to the onset threshold.

A method and system for detecting pacing pulses originating from implanted pacemaker using surface Electrocardiogram (ECG) signals measured at a relatively low sampling rate and also rejecting the pacing artifacts from the recorded surface ECG signals.

A system for monitoring and evaluating the ventricular contractility of a heart muscle includes a device for electrically stimulating the heart muscle of a patient, and an extracorporeal blood pressure sensor. A record, responsive to stimulated ventricular contractions, is created by the pressure sensor. The response record is then evaluated to identify a pressure/time, rate-change in arterial pressure (dp/dt) that results within the time duration of a ventricular contraction in a cardiac cycle. In turn, dp/dt is evaluated as an indicator of ventricular contractility and the health of the patient's heart muscle.

A leadless pacing device may include a power supply providing a power supply voltage, a housing having a first end, a second end, and a side extending between the first end and the second end, and a set of electrodes supported by the housing and in communication with the power supply. The housing may be angled to follow a contour of a patient's heart when the housing is positioned within the coronary sinus of the patient's heart. In some cases, an angled portion of the housing may include a smooth-curve. In some cases, an angled portion of the housing may include a first portion of the housing and a second portion of the housing at an angle of less than one-hundred-eighty degrees with respect to the first portion of the housing. One or more of the electrodes may be exposed on a concave side of the angled housing.

Systems and methods for pacing cardiac conductive tissue are described. In an embodiment, a medical system includes an electrostimulation circuit to generate pacing pulses to stimulate a His bundle or a bunch branch. A sensing circuit senses a far-field ventricular activation, determines a cardiac synchrony indicator using the far-field ventricular activation in response to His bundle or bundle branch pacing, and verifies His-bundle capture status using the determined cardiac synchrony indicator. The system can determine a pacing threshold using the capture status under different stimulation strength values. The electrostimulation circuit can deliver stimulation pulses in accordance with the determined pacing threshold.

A medical device includes a motion sensor configured to sense a motion signal. The medical device includes a control circuit configured to determine at least one ventricular event metric from the motion signal sensed over multiple of atrial cycles, determine that the ventricular event metric meets atrioventricular block criteria and generate an output in response to determining the atrioventricular block.

An example medical device system includes memory configured to store information relating to an occurrence of a cardiac event in a patient and processing circuitry configured to determine the occurrence of the cardiac event in the patient. The processing circuitry is configured to determine at least one of a fall of the patient, a slumping posture of the patient, or a change from an upright posture to a non-upright posture of the patient and that the cardiac event is associated therewith in time. The processing circuitry is configured to, in response to determining that the cardiac event and the at least one of the fall of the patient, the slumping posture of the patient, or the change from the upright posture to the non-upright posture of the patient are associated in time, modulate a response to the cardiac event.

An implantable medical device includes a plurality of electrodes to detect electrical activity, a motion detector to detect mechanical activity, and a controller to determine at least one electromechanical interval based on at least one of electrical activity and mechanical activity. The activity detected may be in response to delivering a pacing pulse according to an atrioventricular (AV) pacing interval using the second electrode. The electromechanical interval may be used to adjust the AV pacing interval. The electromechanical interval may be used to determine whether cardiac therapy is acceptable or whether atrial or ventricular remodeling is successful.

An implantable system, and methodology, for improving a heart's hemodynamic performance featuring (a) bimodal electrodes placeable on the diaphragm, out of contact with the heart, possessing one mode for sensing cardiac electrical activity, and another for applying cardiac-cycle-synchronized, asymptomatic electrical stimulation to the diaphragm to trigger biphasic, diaphragmatic motion, (b) an accelerometer adjacent the electrodes for sensing both heart sounds, and stimulation-induced diaphragmatic motion, and (c) circuit structure, connected both to the electrodes and the accelerometer, operable, in predetermined timed relationships to the presences of valid V-events noted in one of sensed electrical and sensed mechanical, cardiac activity, to deliver diaphragmatic stimulation. The circuit structure includes accelerometer-linked computer structure for enabling selective review, for later operational modifications, of stimulation-produced diaphragmatic motions, and in a modified form, may additionally include timing-adjustment substructure capable of making adjustments in the mentioned timed relationships.

Hemodynamic performance of a heart may be improved by determining, from a location associated with a diaphragm, an occurrence of a valid cardiac event; and then delivering asymptomatic electrical stimulation therapy directly to the diaphragm at termination of a diaphragmatic stimulation delay period that is timed relative to the occurrence of the valid cardiac event. The diaphragmatic stimulation delay period may be automatically established by sensing a plurality of cardiac events directly from a diaphragm; and for each of the sensed cardia events, determining whether the sensed cardiac event represents a valid cardiac event or a non-valid cardiac event. The diaphragmatic stimulation delay period is then calculated based on a plurality of sensed cardia events that are determined to be valid.