Abstract: Methods and tool kits for implanting a lead subcutaneously. Examples include tool kits and methods for establishing first and second subcutaneous tunnels at an angle relative to one another to facilitate introduction of a lead to the subcutaneous space. In an example, a tunneling tool and lead assembly are advanced simultaneously into the subcutaneous space. The tunneling tool may include a curved region configured to transition the tool from the first subcutaneous tunnel to the second subcutaneous tunnel with the use of a single incision.

Abstract: Systems, devices and methods are disclosed related to shapeable lead assemblies. Such lead assemblies can be configured to be shaped in a desired manner before and/or during a procedure, such as, for example, after the lead assembly has been at least partially placed within the anatomy of a subject. The shapeable lead assembly can be shaped during a neuroregenerative procedure to contact and/or otherwise interface with a targeted nerve.

Abstract: The embodiments described herein relate to a self-positioning, quick-deployment low profile transvenous electrode system for sequentially pacing both the atrium and ventricle of the heart in the “dual chamber” mode, and methods for deploying the same.

Abstract: The present disclosure relates to a percutaneous paddle stimulation lead that can be steered during implantation. The percutaneous paddle stimulation lead that can be steered in a thickness plane of percutaneous paddle stimulation lead during implantation.

Abstract: The present disclose generally relates to a system that controls blood pressure based on feedback-based neural stimulation. The system can include an electrode implantable within a nerve (e.g., an intra-fascicular electrode). The system can also include a hermetically-sealed electronics module connected to the electrode to record data related to neural activity from the nerve. The data related to the neural activity is indicative of the blood pressure. The system can also include an external device to communicate with the hermetically-sealed electronics module to receive and analyze the data related to the neural activity.

Abstract: A method for positioning an intravascular catheter may include inserting the intravascular catheter into a venous system of a patient, wherein the catheter includes a plurality of electrodes, and multiple electrodes of the plurality of electrodes are configured to emit electrical signals; positioning a distal portion of the catheter in a first position; using one or more electrodes of the plurality of electrodes to acquire an ECG signal; based on the acquired ECG signal, adjusting the distal portion of the catheter to a second position different from the first position; identifying at least one first electrode of the plurality of electrodes to stimulate a first nerve; identifying at least one second electrode of the plurality of electrodes to stimulate a second nerve; and stimulating at least one of the first and second nerves to cause a contraction of a respiratory muscle.

Abstract: An elongated guide sheath for delivering at least one medical instrument to a body lumen. For reliable and cost effective implantation of an electrode at the AV septum the inventive guide sheath forms a first guiding sleeve and a second guiding sleeve at least partly separated by a shared wall section, wherein the longitudinal axis of the first guiding sleeve and the longitudinal axis of the second guiding sleeve run parallel to a longitudinal guide sheath axis, wherein the wall of the first guiding sleeve and/or of the second guiding sleeve each comprises a slit which runs along at least part of the length of the respective guiding sleeve. Further, a system including the above guide sheath, a first catheter and/or guide wire and a second catheter or electrode is proposed.

Abstract: The present invention relates to a method for positioning a tip of a pacemaker lead that has passed through coronary sinus into an interventricular septum. More particularly, it relates to a method for positioning a tip of a pacemaker lead that has passed through a coronary sinus into an interventricular septum in order to more effectively transmit an electrical stimulus in a treatment using a pacemaker for patients with arrhythmia. A method of positioning a tip of a pacemaker lead, which has passed through a coronary sinus, into an interventricular septum, in order to effectively transmit electrical stimulus, includes: inserting into an intervention wire through a superior vena cava and a coronary sinus to pass through the interventricular septum and then guiding the intervention wire to an inferior vena cava; and positioning the tip of the lead into the interventricular septum by inserting the pacemaker lead along the intervention wire.

Abstract: An apparatus, a system and methods for modulating and monitoring tissue have an elongate member with proximal and distal ends and a plurality of annular stimulating electrodes axially arranged along the elongate member. The stimulating electrodes are disposed near the distal end and are adapted to pass current into tissue. At least one of the annular stimulating electrodes has at least three independent stimulation points on the electrode. The apparatus also includes a plurality of recording electrodes that are adapted to measure local tissue potentials and a plurality of conductors are coupled with the recording and stimulating electrodes. An optional multiple contact connecting terminal may be coupled with the conductors and is disposed near the proximal end of the elongate member.

Abstract: A method for making an implantable lead is related. A pipe is provided. The pipe includes a first end portion, a second end portion opposite to the first end portion, and a middle portion connecting the first end portion and the second end portion. A flexible conductive layer is formed on the middle portion of the pipe. At least one contactor is applied on the first end portion of the pipe. At least one connector is applied on the second end portion of the pipe. At least one wire is placed in the pipe to electrically connect the at least one contactor and the at least one connector.

Abstract: Disclosed is a system including an electrode and a stylet configured to steer the electrode towards its intended position during implantation, and a method for such system's use. An electrode is provided having regions with varied flexibility. A stylet having bends that are indexed to specific regions of flexibility of the electrode may be inserted into the electrode, and upon minimal radial and/or longitudinal movement of the stylet within the electrode, will cause the magnitude of the angle to which the lead is bent to either increase or decrease so as to aid the operator in placement of the electrode.

Abstract: Methods and apparatus are provided for multi-vessel neuromodulation, e.g., via a pulsed electric field. Such multi-vessel neuromodulation may effectuate irreversible electroporation or electrofusion, necrosis and/or inducement of apoptosis, alteration of gene expression, action potential attenuation or blockade, changes in cytokine up-regulation and other conditions in target neural fibers. In some embodiments, the multi-vessel neuromodulation is applied to neural fibers that contribute to renal function. Such multi-vessel neuromodulation optionally may be performed bilaterally.

Abstract: Methods, apparatus, and systems are provided to control contraction of the heart. At least one sensing element receives signals indicating electrical activity of sinus rhythm of the heart. Based on the received signals, the progress of contraction of the heart is determined. Based on the progress of contraction, the chamber of the heart may then be stimulated at a plurality of locations. In another embodiment, a plurality of electrodes are implanted in the left ventricle to stimulate at multiple locations in the left ventricle for the purpose of improving hemodynamic performance and increasing cardiac output in a patient who is suffering from congestive heart failure.

Abstract: An implantable electrical stimulation lead for the treatment of biological conditions includes a lead body with an electrical connector at one end and a pair of monopolar branches at the other end. The lead body has a length ranging from 390 mm to 490 mm to allow for implantation from an incision site further removed from the final positioning site of the electrodes. The branches have lengths ranging from 50 mm to 120 mm for the both branches. These lengths facilitate successful laparoscopic implantation at sites with confined anatomy, such as, near the gastroesophageal junction. The branches include needles and sutures at their ends for suturing anchors positioned on the branches to surrounding tissue. The needles have curves designed to facilitate maneuvering in confined anatomy. A separate lead includes a suture loop connecting the ends of the first and second branches rather than needles. The loop is used to pull the lead through the working channel of an endoscope.

Abstract: Medical lead bodies that are paired each include a braided conductive shield. The braided conductive shield of one lead body has a value for a physical parameter that differs from a value for the physical parameter of the second lead body. The difference in values of the physical parameter for the paired lead bodies results in a reduction in heating from exposure of the lead bodies to radiofrequency energy at electrodes associated with the lead bodies. The lead bodies may be paired by being implanted adjacently to one another. The lead bodies may be further paired by being coupled to a same distal body, such as a paddle containing the electrodes.

Abstract: Methods and apparatus are provided for multi-vessel neuromodulation, e.g., via a pulsed electric field. Such multi-vessel neuromodulation may effectuate irreversible electroporation or electrofusion, necrosis and/or inducement of apoptosis, alteration of gene expression, action potential attenuation or blockade, changes in cytokine up-regulation and other conditions in target neural fibers. In some embodiments, the multi-vessel neuromodulation is applied to neural fibers that contribute to renal function. Such multi-vessel neuromodulation optionally may be performed bilaterally.

Abstract: The invention relates a system (302) for medical stimulation. The system (302) comprises an implantable probe (304) bifurcated into a primary branch (306) and a secondary branch (308) at a bifurcation (310), wherein the probe is provided at its distal end (112, 312) with an electrode (114) for delivering electrical stimulation to tissue. Herein, the primary branch (306) is configured for at least temporarily mechanically co-operating with a guide wire (316) configured for guiding the probe (304) into said tissue whereas the secondary branch (308) is configured for electrically connecting said electrode to a device for generating the electrical stimulation.

Abstract: An improved apparatus and method to catheterize passages is disclosed. The present disclosure provides a catheter having a soft flexible pre-formed distal tip, that when used in combination with commercially available guidewires of variable stiffness, results in the ability to control the direction and angle of wire advancement allowing cannulation of body passages, including those that arise at acute angles. The catheter can have a longitudinal axis, a proximal section and a distal section having a soft flexible pre-formed tip having a curvature of ninety degrees or greater and shape retention. The catheter can have an inner wall that defines a lumen that runs along said longitudinal axis forming a single continuous tube, a reinforcement braid disposed over the inner wall, and an outside covering disposed over the reinforcement braid. A spacer can be added between said wall liner and said reinforcement braid in the proximal end.

Abstract: An implantable medical device having at least one first and one second longitudinally extended electrical functional conductor to transmit therapeutic signals or diagnostic signals or both. The implantable medical device includes one electrode pole connected to the functional conductor, wherein electrical current is delivered to the surrounded bodily tissue using the electrode pole. Electrical potentials may be sensed in the surrounding tissue using the electrode pole, such that the two electrical functional conductors are inductively coupled for defined resonant frequencies and such that RF energy of a first functional conductor is diverted to the second functional conductor. The RF energy is delivered to the surrounding tissue via the second functional conductor and via an electrode pole connected to the second functional conductor.

Abstract: Cardioprotective pre-excitation pacing may be applied to stress or de-stress a particular myocardial region delivering of pacing pulses in a manner that causes a dyssynchronous contraction. Such dyssynchronous contractions are responsible for the desired cardioprotective effects of pre-excitation pacing. A method and device for applying reverse hysteresis and mode switching to the delivery of such cardioprotective pacing are described.

Abstract: A system and method for controlling respiration depth or respiration rate is provided. A bipolar pair of a plurality of electrodes is selected in a location for stimulating a phrenic nerve. Electrical stimulation is delivered through a medical electrical lead electrode proximate phrenic nerve tissue. Modulating respiration is elicited in response to electrical stimulation of the phrenic nerve.

Abstract: A device and method for cardiac pacing is disclosed in which anodal pacing of the left ventricle is provided. Anodal pacing occurs when an anodal surface area is sufficiently small to create an area of hyper-polarization of the myocardial cell membrane. This creates a virtual cathode at a location remote from the anode. The virtual cathode results in depolarization of the heart in a manner similar to the virtual cathode at the true fixed cathode. In addition a device and method for summation anodal pacing is provided in which one anode is common between two or more cathodes. This results in hyperpolarization of a larger segment of the myocardium as compared to non-summation anodal pacing and thereby forms a larger virtual electrode to enable capture of localized, discrete cardiac structures such as the bundle of His or the very proximal portions of the right and left bundles.

Abstract: A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. A number of cardiac cycles occurring in a first cardiac chamber are identified subsequent to the dual chamber pacing pulses. The number of sensed intrinsic events occurring in a second cardiac chamber during the first chamber cardiac cycles is determined as a number of second chamber events. The tachycardia episode is classified in response to the number of second chamber events.

Abstract: A transvenously implantable medical device (TIMD) includes an electrical lead and a control module. The electrical lead includes one or more electrodes and is adapted for transvenous implantation. The electrical lead is also pre-biased to expand from a collapsed state to an expanded state to mechanically engage an internal wall of a blood vessel. The control module is secured to and in electrical communication with the electrical lead. The control module includes a signal management component and a power component disposed in a housing adapted for implantation into the blood vessel. The control module is adapted for at least one of stimulating and sensing a physiologic response using the one or more electrodes of the electrical lead.

Abstract: Improving cardiac response in terms of pressure, ejected volume, and filling and ejection times by cardiac reverse remodelling, including temporary, occasionally harmful stimulation sequences. An original pacing configuration (a) is switched to a modified pacing configuration (b) in a direction opposite to that of an optimization of the hemodynamic parameters, to cause an immediate change in the response to controlled stimulation of the myocardium. This response is assessed based on: the maximum value (P (b, a)) achieved by the peak-to-peak (PEA (i)) of the first peak of endocardial acceleration (PEA) after a pacing configuration change, the mean PEA value (A (b, a)) after stabilization, the PEA variability (V (b, a)) around this average value, and the duration (T (b, a)) of stabilization after the pacing configuration change.

Abstract: Methods, systems and devices efficiently identify cardiac resynchronization therapy (CRT) pacing parameter set(s) that provide improved hemodynamic response relative to an initial CRT pacing parameter set, wherein each CRT pacing parameter set includes at least two CRT pacing parameters. User input(s) are accepted that specify a maximum amount of time and/or parameter sets that can be used to perform testing, and specify relative importance of parameters within the sets. Based on the accepted user input(s), there is a determination of how many different variations of each of the CRT pacing parameters can be tested, and based on this determination different CRT pacing parameter sets are selected and tested to obtain a hemodynamic response measure corresponding to each of the different sets tested. Additionally, one or more of the tested CRT pacing parameter sets, if any, that provide improved hemodynamic response relative to the initial CRT pacing parameter set is/are identified.

Abstract: A single-pass pacing lead capable of sensing and pacing both the atria and the ventricles is described. In some examples, the single-pass pacing lead is connected to a DDD pacemaker. In some examples, the single-pass pacing lead comprises four electrodes. In some examples, the lead includes three electrodes configured to be positioned in or near an atrium, e.g., the right atrium, and one electrode configured to be positioned in or near a ventricle, e.g., the left ventricle, when the lead is implanted. In other examples, the lead includes two electrodes configured to be positioned in each of the atrium and ventricle when the lead is implanted. In some examples, one of the electrodes, which is configured to be positioned proximate the coronary sinus ostium when the lead is implanted, comprises a helical element for fixation of the lead to tissue.

Abstract: A guiding accessory, for use in conjunction with a guidewire and a catheter of an implant system, facilitates passage of an elongate and flexible conductor of a relatively compact therapy delivery device to an implant site, for example, within the cardiac venous system, when a therapy generator of the device is held within a distal portion of the catheter, and the catheter, device and guiding accessory are advanced along the guidewire. The guiding accessory includes a helically extending wall that forms a lumen within which the device conductor and guidewire extend. After advancing the catheter, guiding accessory and device to the implant site, the helically extending wall is unwound from around the device conductor, for removal, preferably, by pulling proximally on a tension line, which is attached to a proximal end of the wall.

Abstract: A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. In one embodiment, a single chamber pacing pulse is delivered in response to detecting a tachycardia. Dual chamber pacing pulses are delivered subsequent to the single chamber pacing pulse. An intrinsic depolarization is sensed subsequent to delivering the dual chamber pacing pulses. The tachycardia episode is classified in response to the sensed intrinsic depolarization.

Abstract: A leadless intra-cardiac medical device includes a housing that is configured to be implanted entirely within a single local chamber of the heart. A first electrode is provided on the housing at a first position such that when the housing is implanted in the local chamber, the first electrode engages the local wall tissue at a local activation site within the conduction network of the local chamber. An intra-cardiac extension is coupled to the housing and configured to extend from the local chamber into an adjacent chamber of the heart. A stabilization arm of the intra-cardiac extension engages the adjacent chamber. A second electrode on the intra-cardiac extension engages distal wall tissue at a distal activation site within the conduction network of the adjacent chamber.

Abstract: An implantable system for the defibrillation of the atria of a patient's heart comprises (a) a first catheter configured for insertion into the right atrium of the heart, preferably without extending into the right ventricle of the heart; a first atrial defibrillation electrode carried by the first catheter and positioned at the atrial septum of the heart (i.e., an atrial septum electrode); (b) a second atrial defibrillation electrode which together with the first atrial defibrillation electrode provides a pair of atrial defibrillation electrodes that are configured for orientation in or about the patient's heart to effect atrial defibrillation, and (c) a pulse generator operatively associated with the pair of atrial defibrillation electrodes for delivering a first atrial defibrillation pulse to the heart of the patient. The second electrode may be configured for positioning through the coronary sinus ostium and in the coronary sinus or a vein on the surface of the left ventricle, such as the great vein.

Abstract: Physiologic demand driven pacing can be used to maintain cardiac synchrony and improve hemodynamic function in patients with heart failure.

Abstract: Methods for determination of timing for electrical shocks to the heart to determine shock strength necessary to defibrillate a fibrillating heart. The timing corresponds the window of most vulnerability in the heart, which occurs during the T-wave of a heartbeat. Using a derivatized T-wave representation, the timing of most vulnerability is determined by a center of the area method, peak amplitude method, width method, or other similar methods. Devices are similarly disclosed embodying the methods of the present disclosure.

Abstract: Methods and devices for modulating heart valve function are provided. In the subject methods, a heart valve is first in structurally modified. Blood flow through the structurally modified heart valve is then monitored, and the heart is paced in response to the monitored blood flow. Also provided are devices, systems and kits that find use in practicing the subject methods. The subject methods find use in a variety of applications.

Abstract: An implantable cardiac stimulation device provides measurement of intrinsic heart activity metrics while sustaining pacing of the heart. The device includes a pulse generator that delivers pacing pulses to a first chamber of corresponding chambers of a heart, and a sensing circuit that senses a conducted evoked response of a second chamber of the corresponding chambers of the heart in response to the pacing pulse to provide an electrical signal representing the conducted evoked response. The device further includes a measuring circuit that measures a metric of the electrical signal to approximate a corresponding metric of an intrinsic electrical feature of the second chamber.

Abstract: An embodiment includes a main lead assembly having a proximal portion adapted for connection to a device and a distal portion adapted for placement in a coronary sinus, the distal portion terminating in a distal end for placement proximal a left ventricle. Additionally, the main lead assembly includes a left ventricular electrode located at its distal end which is adapted to deliver cardiac resynchronization therapy to reduce ventricular wall stress. The main lead assembly also includes a fat pad electrode disposed along the main lead assembly a distance from the distal end to position the fat pad electrode proximal to at least one parasympathetic ganglia located in a fat pad bounded by an inferior vena cava and a left atrium. The fat pad electrode is adapted to stimulate the parasympathetic ganglia to reduce ventricular wall stress.

Abstract: A system for the endocardial stimulation/defibrillation of the left ventricle. This system includes a generator (60) and an endocardial lead. The lead includes a lead body (26) whose distal end (30) extends into the right ventricle (14) and is provided with a mechanism to anchor (32) the distal end to the interventricular septum (20). The lead body carries on it a stimulating and/or defibrillation electrode (38) (64, 66). A microcable (42) extends into the lead body and beyond, with an intermediate portion (56) crossing from one side of the interventricular septum (20) to the other, and an active free portion (58) that emerges in the left ventricle (16). The microcable is coupled to the generator, to produce an electric field (62) between, on one hand, the stimulation electrode (38) or defibrillation electrode (64, 66) of the lead body and, on the other hand, a bare region of the active free portion (58) of microcable (42).

Abstract: A power supply for an implantable cardioverter-defibrillator for subcutaneous positioning between the third rib and the twelfth rib and using a lead system that does not directly contact a patient's heart or reside in the intrathoracic blood vessels and for providing anti-tachycardia pacing energy to the heart, comprising a capacitor subsystem for storing the anti-tachycardia pacing energy for delivery to the patient's heart; and a battery subsystem electrically coupled to the capacitor subsystem for providing the anti-tachycardia pacing energy to the capacitor subsystem.

Abstract: A neurostimulating lead having a stent-like anchor is described. A distal portion of the lead is mounted to an exterior of an expandable, stent-like lead anchor. The stent-like lead anchor is formed from a superelastic material and is adapted to transition from a collapsed configuration to an expanded configuration upon deployment in a vessel. In the expanded configuration, the lead anchor presses the distal portion of the lead against at least one vessel wall of a vessel in which the lead is deployed securing and stabilizing the distal portion of the lead within the vessel.

Abstract: A method for pacing a left ventricle of a heart includes delivering a pacing pulse via a first electrode to activate a first papillary muscle and another pacing pulse via a second electrode to activate a second papillary muscle.

Abstract: A lead assembly includes a lead with a distal end and a proximal end. The lead includes a plurality of electrodes disposed at the distal end and a plurality of terminals disposed at the proximal end. The lead also defines at least one central lumen and a plurality of outer lumens. The central and outer lumens extend from the proximal end to the distal end such that the plurality of outer lumens extend laterally from the at least one central lumen. The lead further includes a plurality of conductive wires. Each conductive wire couples at least one of the plurality of electrodes electrically to at least one of the plurality of terminals. At least two conductive wires are disposed in each of the plurality of outer lumens.

Abstract: A multi-lead system includes a first lead and a second lead. The first lead includes a distal end and a first plurality of electrodes disposed along the distal end of the first lead. The first plurality of electrodes are configured and arranged in a first electrode axis. The second lead includes a distal end and a proximal end. A second plurality of electrodes is disposed along the distal end of the second lead. The second plurality of electrodes are configured and arranged in a second electrode axis. The second lead also includes at least one bend between the distal end and the proximal end to allow for linear alignment of the first electrode axis with the second electrode axis to form a combination electrode axis when the first lead and the second lead are implanted.

Abstract: A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. In one embodiment, a single chamber pacing pulse is delivered in response to detecting a tachycardia. Dual chamber pacing pulses are delivered subsequent to the single chamber pacing pulse. An intrinsic depolarization is sensed subsequent to delivering the dual chamber pacing pulses. The tachycardia episode is classified in response to the sensed intrinsic depolarization.

Abstract: Exemplary techniques and systems for interpolating left ventricular pressures are described. One technique interpolates pressures within the left ventricle from blood pressures gathered without directly sensing blood pressure in the left ventricle.

Abstract: Techniques are provided for detecting heart failure or other medical conditions within a patient using an implantable medical device, such as pacemaker or implantable cardioverter/defibrillator, or external system. In one example, physiological signals, such as immittance-based signals, are sensed within the patient along a plurality of different vectors, and the amount of independent informational content among the physiological signals of the different vectors is determined. Heart failure is then detected by the implantable device based on a significant increase in the amount of independent informational content among the physiological signals. In response, therapy may be controlled, diagnostic information stored, and/or warning signals generated. In other examples, at least some of these functions are performed by an external system.

Abstract: The present invention provides for fitting a multimodal hearing system to a recipient. Such fitting may include determining a desired perception for an input signal, receiving a measurement of a perception evoked by applying to the recipient one or more stimulation signals that correspond to the input signal, wherein the one or more stimulation signals applied using two or more stimulation modes, and each stimulation signal is determined using stimulus mode weighting, and adjusting one or more of the stimulus mode weightings based on the difference between the measured evoked perception and the desired perception. A multimodal hearing system is able to stimulate using an acoustic, electrical, mechanical mode and/or photo effect mode.

Abstract: The invention relates to an intracardial implantable electrode line for connection to an implantable medical device, in particular a cardiac pacemaker or cardioverter/defibrillator or the like, which has an acceleration sensor in the area of its distal end, which is implemented to record and differentiate acceleration values in at least two different directions. The invention additionally relates to a cardiac stimulation configuration which also has a cardiac stimulator in addition to such an electrode line.

Abstract: Techniques are provided for detecting atrial events that might be hidden due to the operation of a post-ventricular atrial blanking (PVAB) interval or other atrial channel blanking interval. In one example, candidate atrial events are identified within signals occurring during the PVAB interval. Then, a determination is made as to whether the candidate atrial event is a true atrial event based on a comparison of characteristics of the candidate atrial event with characteristics of prior known atrial events within the patient. By comparing the characteristics of the “hidden” event with the characteristics of prior known atrial events within the patient, a quick and accurate determination can be made whether the event should be counted as a P-wave. In this manner, hidden atrial arrhythmias can be detected and mode switch oscillations can be reduced or eliminated.

Abstract: Methods for ultrasonically joining portions of a medical lead are provided. One method includes providing a conductor, a fitting and a coil electrode. The conductor has a distal portion that includes an inner conductive portion and an outer insulative portion. The fitting has a first cavity and a second cavity, the first cavity being sized and configured to receive the distal portion of the conductor and the second cavity being sized and configured to receive a portion of the coil electrode. The conductor is ultrasonically welded within the first opening, providing a mechanical and electrical attachment. The coil electrode is also electrically coupled to the fitting, providing an electrical pathway from the conductor to the coil electrode. Also provided are medical leads including ultrasonic bonds and other methods of ultrasonically joining portions of a medical lead.

Abstract: A method of identifying the fossa ovalis in a patient by positioning one or more electrodes against the tissue of the interatrial septum of the patient and acquiring unipolar and/or bipolar electrograms of the tissue of the interatrial septum while moving the electrodes to a plurality of positions against the tissue of the interatrial septum. The fossa ovalis is identified on the basis of unipolar voltage reduction, signal fractionation, broadened signal, reduced signal slew rate, reduced local myocardial impedance, increased phase angle and/or increased pacing threshold. An apparatus for identifying the fossa ovalis is also provided.