Abstract: Techniques for pacing the heart of a patient as a function of a pressure value make use of a pressure monitor that receives a signal from a pressure sensor in the heart. The pressure monitor measures a pressure value. The pressure monitor may, for example, estimate the pulmonary artery diastolic pressure if the pressure sensor is located in the right ventricle, or calculate the mean central venous pressure if pressure sensor is located in the right atrium. The energy level of the pacing pulses delivered to the patient's heart by a pacemaker is modulated as a function of the pressure value. Modulating the energy level of the pacing pulses modulates the cardiac output of the patient's heart.

Abstract: The invention is directed to techniques for monitoring the condition of a patient, such as a patient having congestive heart failure, and appropriately modifying the patient's drug therapy as a function of a pressure in the patient's heart, such as the estimated pulmonary artery diastolic pressure. The drugs may be administered by an implanted drug delivery device. The drug selection, the drug dosage or both may be controlled as a function of the pressure and/or the activity level of the patient.

Abstract: Techniques for pacing the heart of a patient as a function of a pressure value make use of a pressure monitor that receives a signal from a pressure sensor in the heart. The pressure monitor measures a pressure value. The pressure monitor may, for example, estimate the pulmonary artery diastolic pressure if the pressure sensor is located in the right ventricle, or calculate the mean central venous pressure if pressure sensor is located in the right atrium. The energy level of the pacing pulses delivered to the patient's heart by a pacemaker is modulated as a function of the pressure value. Modulating the energy level of the pacing pulses modulates the cardiac output of the patient's heart.

Abstract: Techniques for pacing the heart of a patient as a function of a pressure value make use of a pressure monitor that receives a signal from a pressure sensor in the heart. The pressure monitor measures a pressure value. The pressure monitor may, for example, estimate the pulmonary artery diastolic pressure if the pressure sensor is located in the right ventricle, or calculate the mean central venous pressure if pressure sensor is located in the right atrium. The energy level of the pacing pulses delivered to the patient's heart by a pacemaker is modulated as a function of the pressure value. Modulating the energy level of the pacing pulses modulates the cardiac output of the patient's heart.

Abstract: A method and apparatus for adjusting the electrogram (EGM) sensitivity level of an implantable medical device using intracardiac pressure data. An EGM is monitored to detect electrical events and intracardiac pressure is monitored to detect pressure waves. The electrical waves and pressure waves are analyzed to determine the presence of a one-to-one correlation, with the absence of a one-to-one correlation indicating the need to adjust the sensitivity level.

Abstract: The invention is directed to techniques for electrode placement around a heart. A harness having one or more attachment sites may be secured around the heart, and electrodes may be secured at the attachment sites as desired by the physician for the patient. The electrodes may be, for example, pacing and sensing electrodes, defibrillation electrodes, or any combination thereof. The harness holds the electrodes in place and also impedes the progress of ventricular dilation. The electrodes attached to the harness may be used for any of several purposes, such as cardiac resynchronization, selective defibrillation, measurement of impedance, pacing and cardioversion.

Abstract: A pacemaker provides multi-chamber pacing with a pacing interval that can be programmed and adapted in response to cardiac output measurements for a given patient. In a typical embodiment, the pacemaker may provide pacing stimuli to both ventricles of a heart. In addition, the invention may include a measurement device that incorporates first and second blood oxygen saturation sensors for deployment in the left and right ventricle. The oxygen saturation sensors provide a differential measurement that can be used to calculate cardiac output in accordance with the Fick method. The oxygen saturation sensors may be carried by a common trans-septal lead that positions one of the sensors proximate the right ventricle and the other sensor proximate the left ventricle. Alternatively, the oxygen saturation sensors may be deployed via separate leads. Whether single or dual leads are used to carry the oxygen saturation sensors, a respective lead may optionally carry electrodes for sensing, pacing, or both.

Abstract: In one embodiment, a method includes sensing depolarizations of a heart at a plurality of different locations, and determining a sequence of the sensed depolarizations. The method may further include identifying a tachycardia condition and stimulating the heart at the plurality of locations based on the determined sequence. For example, the method may be implemented by an implantable medical device in order to improve anti-tachycardia pacing (ATP).

Abstract: An medical electrical lead in embodiments of the teachings may include one or more of the following features: (a) a lead body having a proximal end and a distal end, (b) a conductor traversing from the proximal end to the distal end, (c) an electrode disposed at the distal end of the lead body and electrically coupled to the conductor adapted to electrically stimulate a heart, (d) occlusion fabric disposed at the distal end of the lead body and supported by the electrode in a shape adapted to cover holes in the heart, and (f) a second electrode adapted to provide bipolar electrical stimulation of the heart.

Abstract: A plurality of sensors are disposed in and around the heart of a patient to collect data such as various electrical parameters, pressure parameters and temperature parameters. The data collected via the sensors may be organized and stored according to cardiac rhythm type. The organization of data according to cardiac rhythm type allows the patient's physician to be better able to monitor how the various parameters are related to the various cardiac rhythm types. In a typical embodiment, one or more of the sensors may be deployed on a single lead implanted in the heart.

Abstract: A biatrial and/or biventricular pacing system is used in a diagnostic context. By placing a pacing/sensing lead in three or four chambers of the heart, various conduction sequences can be determined and the originating chamber of various arrhythmias can be identified. This information is stored temporarily in the pacemaker until it is extracted for analysis.

Abstract: The invention is directed to techniques for monitoring the condition of a patient, such as a patient having congestive heart failure, and appropriately modifying the patient's drug therapy as a function of a pressure in the patient's heart, such as the estimated pulmonary artery diastolic pressure. The drugs may be administered by an implanted drug delivery device. The drug selection, the drug dosage or both may be controlled as a function of the pressure and/or the activity level of the patient.

Abstract: Techniques are described for estimating a rate of blood flow from a heart, such as a stroke volume or a cardiac output, as a function of a pressure in the heart. A pressure monitor may measure pressure values, and identify the times at which pressure values and valve opening and closing occur. The pressure monitor may estimate a velocity-time function as a function of the measured pressures and identified times, and may calculate a velocity-time integral by integrating the velocity-time function. The pressure monitor may also calculate an estimated velocity-time integral directly as a function of the measured pressures and the identified times. The pressure monitor may calculate the stroke volume or cardiac output using the velocity-time integral. The pressure monitor may control a delivery of therapy by an implantable medical device as a function of the stroke volume or cardiac output.

Abstract: The invention is directed to techniques for monitoring the condition of a patient, such as a patient having congestive heart failure, and appropriately modifying the patient's drug therapy as a function of a pressure in the patient's heart, such as the estimated pulmonary artery diastolic pressure. The drugs may be administered by an implanted drug delivery device. The drug selection, the drug dosage or both may be controlled as a function of the pressure and/or the activity level of the patient.

Abstract: In a system that provides bi-atrial and/or bi-ventricular pacing, the system adjusts an interval between paces delivered to the atria, and/or an interval between paces delivered to the ventricles, as a function of pressure data from the heart. In an exemplary embodiment, the system uses the pressure data from the ventricles to identify the times that each ventricle begins ejection of blood. The system may adjust the interval between paces to cause the ventricles to begin ejection at the same time, or to cause one ventricle to commence blood ejection prior to the other ventricle with a desired time offset. The system may further adjust the interval in response to changing conditions, such as a changing heart rate.

Abstract: In a system that includes a ventricular pacemaker, the system adjusts an atrioventricular delay to synchronize the onset of isovolumetric contraction with the completion of ventricular filling. The system adjusts the atrioventricular delay as a function of electrical and pressure data from the heart. The system further adjusts the atrioventricular delay as a function of measurements of the time interval between a cardiac occurrence such as a ventricular pace and the completion of ventricular filling. The system may also adjust the atrioventricular delay as a function of the heart rate.

Abstract: A method and apparatus provides a sensed AV delay and/or a paced AV delay following an atrial sensed event and/or an atrial paced event, respectively. The AV delay is a predetermined time period initiated by the respective occurrence of the atrial sensed event or atrial paced event. A ventricular safety pacing window is defined during at least an initial portion of the AV delay. Ventricular events are sensed during the AV delay. If a ventricular event is sensed during the ventricular safety pacing window, then a commitment is made to the delivery of a ventricular safety pace upon expiration of the AV delay.

Abstract: The left-ventricle and right-ventricle of the heart are pacing with alternating polarity pulses to conserve power and provide other benefits. The left ventricle is stimulated with a first polarity pulse delivered to a first electrode implanted in left-ventricle endocardial tissue. An interval is delayed after the first electrode has begun stimulating the left-ventricle. Polarity is switched from the first electrode and a second electrode. The right ventricle is stimulated with a second polarity pulse delivered to the second electrode implanted in right-ventricle endocardial tissue.

Abstract: Techniques are described for estimating a rate of blood flow from a heart, such as a stroke volume or a cardiac output, as a function of a pressure in the heart. A pressure monitor may measure pressure values, and identify the times at which pressure values and valve opening and closing occur. The pressure monitor may estimate a velocity-time function as a function of the measured pressures and identified times, and may calculate a velocity-time integral by integrating the velocity-time function. The pressure monitor may also calculate an estimated velocity-time integral directly as a function of the measured pressures and the identified times. The pressure monitor may calculate the stroke volume or cardiac output using the velocity-time integral. The pressure monitor may control a delivery of therapy by an implantable medical device as a function of the stroke volume or cardiac output.

Abstract: In one embodiment, the invention is directed to an implantable medical lead comprising a lead including a proximal end, a distal end, and an electrode. The lead may also include tissue fixation structures on the lead a distance from the electrode, wherein the tissue fixation structures exploit acute and chronic fibrous tissue growth with respect to the lead to enhance fixation of the lead to tissue and thereby secure the electrode in an implanted position. In some cases, the tissue fixation structures may include fibrous growth holes to exploit acute and chronic fibrous tissue growth and advantageously anchor the lead within tissue.