The present invention relates to systems and methods for determining regions of interest to be ablated for treatment of cardiac arrhythmia, such as atrial fibrillation, and, more particularly, to systems and methods for determining atrial fibrillation regions of interest to be ablated using maps representing detected electrical activity of the heart and maps representing spatio-temporal manifestations of the conditions indicative of the electrical activity of the heart.
Cardiac arrhythmia includes different types of abnormal or irregular heart rhythms, such as, for example, atrial fibrillation (AF), which is characterized by rapid and irregular beating. Under normal heart conditions, a heartbeat is produced by electrical pulses (i.e., signals) which originate in the upper chambers (i.e., atria) of the heart and pass through the atria through the atrioventricular (AV) node to a pair of lower chambers (i.e., ventricles) of the heart. As the signals pass through the atria, the atria contract and pump blood from the atria into the ventricles. As the signals pass through the AV node to the ventricles, the ventricles are caused to contract, pumping out blood from the heart to the body. During conditions of AF, however, the signals in the atria become chaotic and cause the heart to beat irregularly.
AF can negatively affect the physical, psychological and emotional quality of a person's life. AF can progressively increase in severity and frequency and, if left untreated, may lead to chronic fatigue, congestive heart failure or stroke. One type of AF treatment includes prescribed medications, such as rhythm control medications and medications used to manage the increased risk of stroke. These medications must be taken daily and indefinitely. Another type of AF treatment includes cardioversion, which attempts to restore a normal heart rhythm by providing electric shocks to the heart through electrodes placed on the chest. In some persistent types of AF, cardioversion is either ineffective or cannot be attempted.
Recent approaches for treating AF include minimally invasive ablation procedures (e.g., catheter ablation) in which the heart tissue is ablated to terminate electrical pathways and block faulty electrical impulses that can cause heart rhythm disorders.
A method of determining target heart ablation regions is provided which includes detecting, via a plurality of sensors, electro-cardiogram (ECG) signals. Each ECG signal is detected via one of the plurality of sensors and indicates electrical activity of a heart over time. The method also includes determining, for each of the plurality of ECG signals, a plurality of local activation times (LATs) occurring over time. Each LAT indicates a time of electrical activation for an area the heart. The method further includes generating, based on the determined plurality of LATs of each of the plurality of ECG signals, mapping information for one or more maps representing the electrical activity of the heart and determining a region of interest (ROI) of the heart by identifying the ROI as a region of the heart exhibiting conditions indicative of cardiac arrhythmia based on the generated mapping information for the one or more maps representing the electrical activity of the heart.
A system for determining target heart ablation regions is provided which includes a plurality of sensors each configured to detect one of a plurality of electro-cardiogram (ECG) signals each indicating electrical activity of a heart over time. The system also includes a processing device which includes one or more processors configured to determine, for each of the plurality of ECG signals, a plurality of local activation times (LATs) occurring over time. Each LAT indicates a time of electrical activation for an area the heart. The one or more processors are further configured to generate, based on the determined plurality of LATs of each of the plurality of ECG signals, mapping information for one or more maps representing the electrical activity of the heart and determine a region of interest (ROI) of the heart by identifying the ROI as a region of the heart exhibiting conditions indicative of cardiac arrhythmia based on the generated mapping information for the one or more maps representing the electrical activity of the heart.
A non-transitory computer readable medium is provided which includes instructions for causing a computer to execute a method of determining target heart ablation regions. The instructions include detecting, via a plurality of sensors, electro-cardiogram (ECG) signals. Each ECG signal is detected via one of the plurality of sensors and indicates electrical activity of the heart over time. The instructions also include determining, for each of the plurality of ECG signals, a plurality of local activation times (LATs) occurring over time. Each LAT indicates a time of electrical activation for an area the heart. The instructions further include generating, based on the determined plurality of LATs of each of the plurality of ECG signals, mapping information for one or more maps representing the electrical activity of the heart and determining a region of interest (ROI) of the heart by identifying the ROI as a region of the heart exhibiting conditions indicative of cardiac arrhythmia based on the generated mapping information for the one or more maps representing the electrical activity of the heart.
A more detailed understanding can be had from the following description, given by way of example in conjunction with the accompanying drawings wherein:
Conventional methods and systems used for catheter ablation typically include inserting the catheter through an incision in the skin and guided up to the heart. Before ablation is performed, intra-cardiac electrocardiogram (IC ECG) signals of the heart are acquired via electrodes placed at different areas of the heart. The signals are monitored and used to provide information to determine whether one or more areas of the heart are causing the irregular heart rhythm. The conventional methods and systems used to determine these areas to be ablated, however, are time consuming (e.g., several hours) and rely on medical personnel with specific expertise and experience (typically requiring many hours of training).
Embodiments disclosed herein employ systems, apparatuses and methods of determining potential regions of interest (ROIs) to be targeted for ablation. Various mapping techniques are utilized to generate mapping information for one or more maps of the electro-physical conditions of the AF substrate and mapping information for one or more maps representing a spatio-temporal manifestation of the AF process to provide efficient and accurate determination of potential or target ablation ROIs. Mapping techniques utilize various parameters (e.g., cycle, earliness, R-S complex, conduction velocity (CV), block and fractionation) of acquired IC ECG signals and detected local activation times (LATs) to identify potential evidence of drivers and perpetuators of the AF substrate. Identification of the evidence of potential drivers and perpetuators is used to provide mapping (e.g., driver maps and perpetuator maps) of the AF substrate. Mapping techniques also include utilizing the various parameters of the acquired IC ECG signals and detected local activation times to generate mapping information for providing maps (e.g., activation/wave maps, CV maps, fractionation maps, voltage maps and block maps) which potentially represents the spatio-temporal manifestation of the AF process. The mapping of the spatio-temporal manifestation of the AF process can be used in addition to, or alternative to, the mapping of the AF substrate to identify potential ablation ROIs. The mapping techniques are used to potentially reduce AF map analysis training time, increase success rates resulting from ablation and facilitate efficient interpretation of AF maps. For simplification purposes, embodiments described herein refer to systems and methods used for the treatment of AF. It is noted however, embodiments may be used for the treatment of any type of cardiac arrhythmia including different types of abnormal or irregular heart rhythms.
For example, as shown in
Critical AF can be classified according to characteristics (e.g., areas of activation) that can be derived from IC ECG signals. Areas of activation may be identified as potential contributing factors to AF. As shown in
Drivers 108 and perpetuators 110 may be represented (e.g., mapped) according to their spatio-temporal manifestation. As shown in
Mapping and identification of drivers 108 and perpetuators 110 can also be based on one or more additional factors which may potentially contribute to AF or parameters which may potentially characterize the AF substrate (i.e., the AF process itself) and/or the manifestation of the AF process. For example, AF parameters or AF factors used to identify potential focal sources 108 include omnidirectional activation spread of activation from a point, earliness (e.g., focal source which starts after an excitable gap), triggers such as fast firing (e.g., short cycle-length and high dominant frequency) foci and breakthroughs (e.g., pulmonary veins (PV), free wall and transmural, endocardial and epicardial) and micro re-entry circuit which manifests as focal source and short-radius re-entry circuits which can manifest as a driver 108 depending on the specific anisotropic structure of the central obstacle.
AF parameters or AF factors used to map and identify RAP sources 114 include, for example, repetitive cycles, rotors which can manifest as a driver source 108, structural or functional anisotropy (e.g., localized or distributed), and short-radius re-entry circuits which can manifest as either a driver 108 or a perpetuator 110, depending on specific anisotropic structure of the central obstacle.
AF parameters or AF factors used to map and identify perpetuators 110 include, for example, extension (increased) path length, anatomical (pathological) block lines, fibrosis, stable functional block lines (e.g., areas of prolonged refractoriness), criticality (e.g., shortest path around block line>path length) and fibrillatory conduction factors (e.g., dissociated waves, re-entry circuit factors).
The detected IC ECG signals and the detected extra-cardiac signals are processed (e.g., recorded over time, filtered, fractionated, mapped, combined, interpolated, etc.) by processing device 204 and displayed on display device 206.
Embodiments may include any number of sensors 210 used to detect ECG signals, including sensors used to detect IC ECG signals and extra-cardiac ECG signals. For simplification purposes, systems and methods described herein refer to the detection and use of IC ECG signals. It is noted, however, that embodiments may utilize IC ECG signals or extra-cardiac ECG signals or a combination of both IC ECG signals and extra-cardiac ECG signals.
Processing device 204 may include one or more processors each configured to process the ECG signals. Each processor of processing device 204 may be configured to record ECG signals over time, filter ECG signals, fractionate ECG signals into signal components (e.g., slopes, waves, complexes), map ECG signals, combine ECG signal information, map and interpolate mapping information, etc.
Display device 206 may include one or more displays each configured to display ECG signals, ECG signal information, maps of the AF process and maps representing a spatio-temporal manifestation of the AF process.
The catheter sensors 208 and the extra cardiac sensors 210 may be in wired or wireless communication with processing device 204. Display device 206 may also be in wired or wireless communication with processing device 204.
For each IC ECG signal acquired at block 302, one or more LATs of the corresponding pre-processed IC ECG signal is (are) detected at block 304. The LAT quality (shown as LATQ in
As shown at decision point 310, the method 300 includes determining whether to reposition the catheter based on the LAT quality of the signal and the AF complexity. A typical characteristic of high quality IC ECGs is little base line wander (e.g., low baseline vs. IC ECG RMS amplitude, limited ventricular far-field potentials vs. IC ECG RMS amplitude). IC ECG signals characteristics include discernable atrial complexes (e.g., confined (˜50 ms) complexes separated by isoelectric segments repeating slopes, 50-200 ms interval; about 150 ms median) during AF. High quality complexes characteristic typically have considerable amplitudes and steep downward slopes (vs. upward slopes) within complexes. Characteristics of the IC ECG signals may be combined into a single measurable characteristic or parameter (e.g., having a measurable value of 0%-100%) to define LAT quality. The LAT quality may be compared to the AF complexity to determine whether to reposition the catheter.
In some embodiments, quality is defined by an ability to map AF for a level of AF complexity. Determining whether to reposition the catheter may include generating a map and determining whether the generated map can be used (e.g., is adequate) to map AF based on whether a level of coverage of a mapping electrode meets (e.g., matches) a level of AF complexity. The ability to map AF for a level of AF complexity may include meeting a map threshold level (e.g., adequate level, trustworthy level). A single parameter (i.e., mapping coverage) is used to define a level of coverage of the mapping electrode. Examples of characteristics that are combined to define the mapping coverage include: (1) contact of the mapping electrode (e.g., contact with active tissue (wall) related to covered area and LAT accuracy); (2) resolution of the electrodes (e.g., distances and electrode sensitivity radii between electrodes, including mean, minimum and maximum and distances); and (3) quality of the IC ECG and associated annotations provided by a detection algorithm.
AF complexity may include complexity of activation during AF creating wave dissociation (block lines), fusion and wave curvature. Accordingly, a map may be determined as a map which can be used (e.g., trustworthy or adequate) to map AF when, given a certain level of AF complexity (e.g., measured along y-axis), the mapping coverage (including signal and annotation quality measured along x-axis) is sufficient to map the AF complexity. If not, the trustworthiness of the map may become compromised or inadequate.
Signals may then be analyzed using the trustworthy or adequate maps to determine whether the catheter should be repositioned. If it is determined at decision point 310 to reposition the catheter, the catheter (e.g., catheter 202) is repositioned at block 312 and a new IC ECG signal is acquired at block 302. If it is determined at decision point 310 that the catheter should be repositioned, the method 300 continues to “point A” 313 (shown in
For example, with regard to the AF Substrate 314 shown in
As shown, a driver map 328 is generated from the cycle information 318, the earliness information 324 and the R-S complex information 320. A perpetuator map 330 is generated from the CV Block information 326 and the fractionation information 322. As shown, the information used to generate the driver map 328 and the information used to generate the perpetuator map 330 are combined (e.g., a single map, overlaid maps or adjacent maps in one display area) to generate a combined driver/perpetuator map 334. The combined driver/perpetuator map 334 may then be used (e.g., interpolated as part of an exemplary map interpolation layer) to determine one or more ablation ROIs 350.
With regard to the AF Process 316 shown in
Activation/wave maps may, for example, include a map representing an incidence of source behavior presenting the earliest activation of one of a plurality of electrodes restricted by the same wave, such as indicating a percentage of activation waves detected by a corresponding electrode activated earlier than neighboring electrodes though restricted by neighbors activated by the same wave. Activation Wave maps may, for example, also include a map representing the incidence of electrode positions associated with a fibrillation wave start.
Each IC ECG signal is used to independently generate voltage maps 342 and fraction maps 340. The information used to generate maps 336-344 is combined to provide combined maps or video 346. In some embodiments, the information used to generate the activation/wave maps 336 and Voltage maps 342 is combined to generate a combined activation/wave/voltage map or video and the information used to generate the CV maps 338, the block maps 344 and the fraction maps 340 are combined to generate a combined CV/block/fraction map or video. The combined maps/video 346 are analyzed (e.g., interpreted by medical personnel as part of an exemplary map interpretation layer) at block 348 to determine ROIs to be ablated at block 350. The combined maps/video 346 represent a spatio-temporal manifestation of the AF process which can be easily visualized and interpreted, facilitating an efficient and accurate process for determination of ROIs for ablation. Determined ROIs may be represented (e.g., displayed), for example, by color, by 3-D contour on a 4-D map, by icons (e.g., dynamically changing icons), etc.
In some embodiments, both the combined driver/perpetuator map 334 and the combined maps/video 346 are used to determine ROIs for ablation at block 350. In some embodiments either the combined driver/perpetuator map 334 or the combined maps/video 346 are used to determine ROIs for ablation at block 350. For example, the combined driver/perpetuator map 334 can be used to determine ROIs for ablation at block 350 without using (e.g., viewing, analyzing) the combined maps/video 346.
In some embodiments, the quality map 332 is also used in combination with the combined driver/perpetuator map 334 and/or the combined maps/video 346 to determine ROIs for ablation at block 350. The quality map 332 is used to determine the trustworthiness of the generated maps (e.g., driver map 328, perpetuator map 330 and driver/perpetuator map 334) related to AF substrate 314 and the generated maps (e.g., activation/wave maps 336, CV maps 338, fraction maps 340, voltage maps 342 and block maps 344) related to the AF process 316 parameters. If the quality of the quality map is low, the generated maps are less trusted and appointing an ablation ROI (350) must be regarded with an increase level of care (e.g., by a physician) compared to when the quality map indicates high quality signals (IC ECGs) as the basis for the generated maps.
In some embodiments, determining ROIs for ablation at block 350 includes appointing or selecting one or more ablation sites for use in determining one or more ROIs for ablation. For example, ablation sites may be appointed or selected from driver evidence and perpetuator evidence (e.g., determined from the driver map 328, the perpetuator map 330 or the combined driver/perpetuator map 334) and ROIs may be determined based on the appointed sites.
The maps and mapping techniques disclosed herein potentially: (i) reduce AF map analysis training time; (ii) reduce time to determine ROIs for ablation; (iii) facilitate efficient interpretation of AF maps; and (iv) increase ablation success rates for ablation aimed at isolation and extinguishing of drivers, path lengthening, slowing of re-entry circuits, fibrillatory conduction and fractionated potentials.
It should be understood that many variations are possible based on the disclosure herein. Although features and elements are described above in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that to the extent any terms are defined in these incorporated documents in a manner that conflicts with the definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.
The methods provided include implementation in a general purpose computer, a processor, or a processor core. Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine. Such processors can be manufactured by configuring a manufacturing process using the results of processed hardware description language (HDL) instructions and other intermediary data including netlists (such instructions capable of being stored on a computer readable media). The results of such processing can be maskworks that are then used in a semiconductor manufacturing process to manufacture a processor which implements methods described herein.
The methods or flow charts provided herein can be implemented in a computer program, software, or firmware incorporated in a non-transitory computer-readable storage medium for execution by a general purpose computer or a processor. Examples of non-transitory computer-readable storage mediums include a ROM, a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs).
This application claims the benefit of U.S. Provisional Application No. 62/278,676 filed on Jan. 14, 2016, which is incorporated by reference as if fully set forth. This application incorporates by reference as if fully set forth Attorney Docket Nos. JNJ-BI05643USNP titled “Region of Interest Focal Source Detection Using Comparisons of R-S Wave Magnitudes and LATs of RS Complexes,” JNJ-BI05643USNP1 titled “Region of Interest Rotational Activity Pattern Detection,” JNJ-BI05643USNP2 titled “Identification of Fractionated Signals,” JNJ-BI05643USNP4 titled “Non-Overlapping Loop-Type Or Spline-Type Catheter To Determine Activation Source Direction And Activation Source Type,” and JNJ-BI05643USNP5 titled “Region of Interest Focal Source Detection,” all filed on the same date as the present application.
Number | Date | Country | |
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62278676 | Jan 2016 | US |