Non-fluoroscopic catheter-based mapping systems in cardiac electrophysiology—from approved clinical indications to novel research usage (original) (raw)
electroanatomical imaging of cardiac electrophysiology
O Ob bj je ec ct ti iv ve e: : More than two decades of research work have shown that magnetocardiographic mapping (MCG) is reliable for non-invasive three-dimensional electroanatomical imaging (3D-EAI) of arrhythmogenic substrates. Magnetocardiographic mapping is now become appealing to interventional electrophysiologists after recent evidence that MCG-based dynamic imaging of atrial arrhythmias could be useful to classify patients with atrial fibrillation (AF) before ablation and to plan the most appropriate therapeutic approach. This article will review some key-points of 3D-EAI and discuss what is still missing to favor clinical applicability of MCG-based 3D-EAI. M Me et th ho od ds s: : Magnetocardiographic mapping is performed with a 36-channel unshielded mapping system, based on DC-SQUID sensors coupled to second-order axial gradiometers (pick-up coil 19 mm and 55-70 mm baselines; sensitivity of 20 fT/√Hz in above 1 Hz), as part of the electrophysiologic investigation protocol, tailored to the diagnostic need of each arrhythmic patient. More than 500 arrhythmic patients have been investigated so far. R Re es su ul lt ts s: : The MCG-based 3D-EAI has proven useful to localize well-confined arrhythmogenic substrates, such as focal ventricular tachycardia or preexcitation, to understand some causes for ablation failure, to study atrial electrophysiology including spectral analysis and localization of dominant frequency components of AF. However, MCG is still missing software tools for automatic and/or interactive 3D imaging, and multimodal data fusion equivalent to those provided with systems for invasive 3D electroanatomical mapping. C Co on nc cl lu us si io on n: : Since there is an increasing trend to favor interventional treatment of arrhythmias, clinical application of MCG 3D-EAI is foreseen to improve preoperative selection of patients, to plan the appropriate interventional approach and to reduce ablation failure. (Anadolu Kardiyol Derg 2007: 7 Suppl 1; 23-8) K Ke ey y w wo or rd ds s: : magnetocardiography, body surface cardiac mapping, electroanatomical imaging, mathematical modeling, atrial fibrillation, catheter ablation ABSTRACT Riccardo Fenici, Donatella Brisinda
International Journal of Cardiovascular Imaging, 2006
O Ob bj je ec ct ti iv ve e: : More than two decades of research work have shown that magnetocardiographic mapping (MCG) is reliable for non-invasive three-dimensional electroanatomical imaging (3D-EAI) of arrhythmogenic substrates. Magnetocardiographic mapping is now become appealing to interventional electrophysiologists after recent evidence that MCG-based dynamic imaging of atrial arrhythmias could be useful to classify patients with atrial fibrillation (AF) before ablation and to plan the most appropriate therapeutic approach. This article will review some key-points of 3D-EAI and discuss what is still missing to favor clinical applicability of MCG-based 3D-EAI. M Me et th ho od ds s: : Magnetocardiographic mapping is performed with a 36-channel unshielded mapping system, based on DC-SQUID sensors coupled to second-order axial gradiometers (pick-up coil 19 mm and 55-70 mm baselines; sensitivity of 20 fT/√Hz in above 1 Hz), as part of the electrophysiologic investigation protocol, tailored to the diagnostic need of each arrhythmic patient. More than 500 arrhythmic patients have been investigated so far. R Re es su ul lt ts s: : The MCG-based 3D-EAI has proven useful to localize well-confined arrhythmogenic substrates, such as focal ventricular tachycardia or preexcitation, to understand some causes for ablation failure, to study atrial electrophysiology including spectral analysis and localization of dominant frequency components of AF. However, MCG is still missing software tools for automatic and/or interactive 3D imaging, and multimodal data fusion equivalent to those provided with systems for invasive 3D electroanatomical mapping. C Co on nc cl lu us si io on n: : Since there is an increasing trend to favor interventional treatment of arrhythmias, clinical application of MCG 3D-EAI is foreseen to improve preoperative selection of patients, to plan the appropriate interventional approach and to reduce ablation failure. (Anadolu Kardiyol Derg 2007: 7 Suppl 1; 23-8) K Ke ey y w wo or rd ds s: : magnetocardiography, body surface cardiac mapping, electroanatomical imaging, mathematical modeling, atrial fibrillation, catheter ablation ABSTRACT Riccardo Fenici, Donatella Brisinda
Heart Rhythm, 2009
BACKGROUND Mapping of regular cardiac arrhythmias is frequently performed using sequential point-by-point annotation of local activation relative to a fixed timing reference. Assigning a single activation for each electrogram is unreliable for fragmented, continuous, or double potentials. Furthermore, these informative electrogram characteristics are lost when only a single timing point is assigned to generate activation maps. The purpose of this study was to develop a novel method of electrogram visualization conveying both timing and morphology as well as location of each point within the chamber being studied. METHODS Data were used from six patients who had undergone electrophysiological study with the Carto electroanatomic mapping system. Software was written to construct a three-dimensional surface from the imported electrogram locations. Electrograms were time gated and displayed as dynamic bars that extend out from this surface, changing in length and color according to the local electrogram voltage-time relationship to create a ripple map of cardiac activation. Ripple maps were successfully constructed for sinus rhythm (n ϭ 1), atrial tachycardia (n ϭ 3), and ventricular tachycardia (n ϭ 2), simultaneously demonstrating voltage and timing information for all six patients. They showed low-amplitude continuous activity in four of five tachycardias at the site of successful ablation, consistent with a reentrant mechanism. CONCLUSION Ripple mapping allows activation of the myocardium to be tracked visually without prior assignment of local activation times and without interpolation into unmapped regions. It assists the identification of tachycardia mechanism and optimal ablation site, without the need for an experienced computer-operating assistant.
Pace-pacing and Clinical Electrophysiology, 1998
The purpose of the study was to validate, in patients, the accuracy of magnetocardiography (MCG) for three-dimensional localization of an amagnetic catheter (AC) for multiple monophasic action potential (MAP) with a spatial resolution of 4 mm2. The AC was inserted in five patients after routine electrophysiological study. Four MAPs were simultaneously recorded to monitor the stability of endocardial contact of the AC during the MCG localization. MAP signals were band-pass filtered DC-500 Hz and digitized at 2 KHz. The position of the AC was also imaged by biplane fluoroscopy (XR), along with lead markers. MCG studies were performed with a multichannel SQUID system in the Helsinki BioMag shielded room. Current dipoles (5mm; 10mA), activated at the tip of the AC, were localized using the equivalent current dipole (ECD) model in patient-specific boundary element torso. The accuracy of the MCG localizations was evaluated by: (1) anatomic location of ECD in the MRI, (2) mismatch with XR. The AC was correctly localized in the right ventricle of all patients using MRI. The mean three-dimensional mismatch between XR and MCG localizations was 6 ± 2 mm (beat-to-beat analysis). The coefficient of variation of three-dimensional localization of the AC was 1.37% and the coefficient of reproducibility was 2.6 mm. In patients, in the absence of arrhythmias, average local variation coefficients of right ventricular MAP duration at 50% and 90% ofrepolarization, were 7.4% and 3.1%, respectively. This study demonstrates that with adequate signal-to-noise ratio, MCG three-dimensional localizations are accurate and reproducible enough to provide nonfluoroscopy dependant multimodal imaging for high resolution endocardial mapping of monophasic action potentials.
Cardiac mapping: utility or futility?
Indian pacing and electrophysiology journal, 2002
Cardiac mapping is a broad term that covers several modes of mapping such as body surface, 1 endocardial, 2 and epicardial 3 mapping. The recording and analysis of extracellular electrograms, reported as early as 1915, forms the basis for cardiac mapping. 4 More commonly, cardiac mapping is performed with catheters that are introduced percutaneously into the heart chambers and sequentially record the endocardial electrograms with the purpose of correlating local electrogram to cardiac anatomy. These electrophysiological catheters are navigated and localized with the use of fluoroscopy. Nevertheless, the use of fluoroscopy for these purposes may be problematic for a number of reasons, including: 1) the inability to accurately associate intracardiac electrograms with their precise location within the heart; 2) the endocardial surface is invisible using fluoroscopy and the target sites can only be approximated by their relationship with nearby structures such as ribs, blood vessels, and the position of other catheters; 3) due to the limitations of two-dimensional fluoroscopy, navigation is not exact, time consuming, and requires multiple views to estimate the three-dimensional location of the catheter; 4) inability to accurately return the catheter precisely to a previously mapped site; and 5) exposure of the patient and medical team to radiation. Newer mapping systems have revolutionized the clinical electrophysiology laboratory in recent years and have offered new insights into arrhythmia mechanisms. They are aimed at improving the resolution, three-dimensional spatial localization, and/or rapidity of acquisition of cardiac activation maps. These systems use novel approaches to accurately determine the threedimensional location of the mapping catheter and local electrograms are acquired using conventional, well-established methods. Recorded data of the catheter location and intracardiac electrogram at that location are used to reconstruct in real-time a representation of the threedimensional geometry of the chamber, color-coded with relevant electrophysiological information. However, these mapping systems are very expensive and not required for the commoner clinical arrhythmias like atrioventricular nodal reentry (AVNRT), accessory pathway mediated tachycardia (WPW syndrome and concealed pathways) and typical atrial flutter. The purpose of this article is to discuss the possible contribution of newer cardiac mapping system to treat various arrhythmias.
International Congress Series, 2007
Catheter ablation has significantly changed the diagnostic approach and the treatment of cardiac arrhythmias. Being the appropriate localization of the arrhythmogenic target a key-point for effective ablation, new technologies have been recently developed, for three-dimensional (3D) electroanatomical imaging during ablation procedures. However all of them are invasive and cannot be used for preoperative assessment and localization of arrhythmogenic substrates. Magnetocardiographic mapping (MCG) on the contrary is a feasible method, which provide 3D electroanatomical imaging of cardiac sources non-invasively, therefore it can be repeated on ambulatory patients, to define the characteristics of the arrhythmogenic substrate before intervention. MCG detection of electrophysiologic (EP) abnormalities and 3D electroanatomical imaging of arrhythmogenic substrates can be enhanced by simultaneous EP study with amagnetic trans-esophageal atrial pacing. Alternatively minimally invasive, single-catheter multiple monophasic action potential recordings (Multi-MAP) can be aimed at the arrhythmogenic targets identified by MCG. The MCG-guided Multi-MAP EP study is also useful for direct validation of MCG estimate of atrial and ventricular de-repolarization by comparison with simultaneous MAP recordings in sinus rhythm and under pacing. Future robotic navigation of an ablation catheter guided by 3D MCG coordinates of the arrhythmogenic target is foreseeable.
2011
Background-Scar heterogeneity identified with contrast-enhanced cardiac magnetic resonance (CE-CMR) has been related to its arrhythmogenic potential by using different algorithms. The purpose of the study was to identify the algorithm that best fits with the electroanatomic voltage maps (EAM) to guide ventricular tachycardia (VT) ablation. Methods and Results-Three-dimensional scar reconstructions from preprocedural CE-CMR study at 3T were obtained and compared with EAMs of 10 ischemic patients submitted for a VT ablation. Three-dimensional scar reconstructions were created for the core (3D-CORE) and border zone (3D-BZ), applying cutoff values of 50%, 60%, and 70% of the maximum pixel signal intensity to discriminate between core and BZ. The left ventricular cavity from CE-CMR (3D-LV) was merged with the EAM, and the 3D-CORE and 3D-BZ were compared with the corresponding EAM areas defined with standard cutoff voltage values. The best match was obtained when a cutoff value of 60% of the maximum pixel signal intensity was used, both for core (r 2 ϭ0.827; PϽ0.001) and BZ (r 2 ϭ0.511; Pϭ0.020), identifying 69% of conducting channels (CC) observed in the EAM. Matching improved when only the subendocardial half of the wall was segmented (CORE: r 2 ϭ0.808; PϽ0.001 and BZ: r 2 ϭ0.485; Pϭ0.025), identifying 81% of CC. When comparing the location of each bipolar voltage intracardiac electrogram with respect to the 3D CE-CMR-derived structures, a Cohen coefficient of 0.70 was obtained. Conclusions-Scar characterization by means of high resolution CE-CMR resembles that of EAM and can be integrated into the CARTO system to guide VT ablation. (Circ Arrhythm Electrophysiol. 2011;4:674-683.)
Global Electrophysiological Mapping of the Atrium: Computerized Three-Dimensional Mapping System
Pacing and Clinical Electrophysiology, 1997
RODEFELD, M.D., ET AL.: Global Electrophysiological Mapping of the Atrium: Computerized Three-Dimensional Mapping System. The atria are anatomically complex three-dimensional (3-D) structures. Impulse propagation is dynamic and complex during both normal conduction and arrhythmia, Atrial activation has traditionally been represented on two-dimensional surface maps, which have inherent inaccuracies and are difficult to interpret. Interactive computerized 3-D display facilitates interpretation of complex atrial activation sequence data obtained from form-fitting multipoint electrodes. Accordingly, the purpose of this article is to describe the application of 3-D form-fitting electrode molds to the 3-D mapping and display system developed in this laboratory for the study of complex cardiac arrhythmias. Computer generated 3-D surface models are created from a database of serial cross-sectional anatomical images. Points chosen on endocardia} and epicardial surfaces in each cross-sectional image are processed to create polygons defining myocardial wall boundaries. The polygons from adjacent serial images are then combined, to create a 3-D surface model. The discrete anatomical locations of unit electrodes on multipoint electrode templates are then assigned in the proper position on the surface model. Computer analysis of simultaneous activation data from each unit electrode is performed based on parameters set by the user. Activation data from each unit electrode site are displayed on the computer surface model in a color spectrum correlating with a user-defined time scale. Activation sequence maps can be visualized as static isochrone maps, interval maps, or as dynamic maps at variable speeds, from any 3-D perspective. Thus, an interactive computerized 3-D display system is described, which allows anatomically superior analysis and interpretation of complex atrial arrhythmias. (PACE 1997; 20[Pt, I]:2227 20[Pt, I]: -2236 computerized mapping, atrial, cardiac, three-dimensional
2012
Background-A canine right atrial (RA) linear lesion model was used to produce a complex pattern of RA activation to evaluate a novel mapping system for rapid, high resolution (HR) electroanatomical mapping. Methods and Results-The mapping system (Rhythmia Medical, Incorporated) uses an 8F deflectable catheter with a minibasket (1.8 cm diameter), containing 8 splines of 8 electrodes (total 64 electrodes, 2.5 mm spacing). The system automatically acquires electrograms and location information based on electrogram stability and respiration phase. In 10 anesthetized dogs, HR-RA map was obtained by maneuvering the minibasket catheter during sinus rhythm and coronary sinus pacing. A right thoracotomy was performed, and either 1 or 2 (to create a gap) epicardial linear lesions were created on the RA free wall (surgical incision or epicardial radiofrequency lesions). RA maps during RA pacing close to the linear lesions were obtained. A total of 73 maps were created, with 44 to 729 (median 237) beats and 833 to 12 412 (median 3589) electrograms (Յ2 to Յ5 mm from surface geometry), resolution 1.8 to 5.3 (median 2.7) mm, and 2.6 to 26.3 (median 7.3) minutes mapping time. Without manual annotation, the system accurately created RA geometry and demonstrated RA activation, identifying the location of lines of block and presence or absence of a gap in all 10 dogs. Endocardial radiofrequency catheter ablation of a gap (guided by activation map) produced complete block across the gap in all 3 dogs tested. Conclusions-The new HR mapping system accurately and quickly identifies geometry and complex patterns of activation in the canine RA, with little or no manual annotation of activation time.
Reinserting Physiology into Cardiac Mapping Using Omnipolar Electrograms
Cardiac Electrophysiology Clinics, 2019
Cardiac mapping is an essential tool in arrhythmia diagnosis and treatment. Mapping information obtained from signal processing and image display algorithms in present day electroanatomic mapping systems are critically dependent on measured electrograms (EGMs) from catheters. A collection of local activation times (LAT) derived from EGMs within a cardiac chamber Disclosures: D.C. Deno is an employee of Abbott Laboratories, St. Paul, MN. K. Nanthakumar and S. Massé are consultants for Abbott Laboratories, St. Paul, MN. K. Nanthakumar is a consultant for Biosense Webster, Irving, CA. K. Magtibay, A. Porta-Sanchez, S. K. Haldar have nothing to disclose.
Mapping of atrial fibrillation - basic research and clinical applications
2000
Despite five decades of intensive research, mechanisms initiating and stabilising atrial fibrillation (AF) are still not fully understood. Nevertheless, mapping studies, next to clinical trials and research on cellular electrophysiology, have provided key information that has led to a much more profound understanding of the arrhythmia.
Magnetic Electroanatomical Mapping for Ablation of Focal Atrial Tachycardias
Pace-pacing and Clinical Electrophysiology, 1998
Uniform success for ablation of focal athaJ tachycardias has been difficult to achieve using standard catheter mapping and ablation techniques. In addition, our understanding of the complex relationship between atrial anatomy, electrophysiology. and surface ECG P wave morphology remains primitive. The magnetic electroanatomical mapping and display system (CARTO) offers an on-line display of electrical activation and/or signal amplitude related to the anatomical location of the recorded sites in the mapped chamber. A window of electrical interest is established based on signals timed from an electrical reference that usually represents a fixed electrogram recording from the coronary sinus or the atrial appendage. This window of electrical interest is established to include atrial activation prior to the onset of the P wave activity associated with the site of origin of a focal atrial tachycardia. Anatomical and electrical landmarks are defined with limited fluoroscopic imaging support and more detailed global chamber and more focal atrial mapping can be performed with minimal fluoroscopic guidance. A three-dimensional color map representing atrial activation or voltage amplitude at the magnetically defined anatomical sites is displayed with on-line data acquisition. This display can be manipulated to facilitate viewing from any angle. Altering the zoom control, triangle fill threshold, clipping plane, or color range can all enhance the display of a more focal area of interest. We documented the feasibility of using this single mapping catheter technique for localizing and ablating focal atrial tachycardias. In a consecutive series of 8 patients with 9 focal atrial tachycardias, the use of the single catheter CARTO mapping system was associated with ablation success in all but one patient who had a left atrial tachycardia localized to the medial aspect of the orifice of the left atrial appendage. Only low power energy deHvery was used in this patient because of the unavaHahiHty of temperature monitoring in the early version of the Navistar catheter, the location of the arrhythmia, and the history of arrhythmia control with flecainide. No attempt was made to Umit fluoroscopy time in our study population. Nevertheless, despite data acquisition from 120–320 anatomically distinct sites during global and more detaHed focal atrial mapping, total fluoroscopy exposure was typically < 30 minutes and was as little as 12 minutes. The detailed display capabilities of the CARTO system appear to offer the potential of enhancing our understanding of atrial anatomy, atrial activation, and their relationship to surface ECC P wave morphology during focal atrial tachycardias.
Interrogation of the cardiac electroanatomical substrate
2016
Ectopic activation and conduction may give rise to ar rhythmias when a diseased myocardial substrate exists. Electrophysiological mapping studies that record electri cal properties of the heart in sinus rhythm may fail to un cover pro-arrhythmic substrates that are triggered by ectopy. In this study we use simulation and experimental models of clinical, trackable, loop catheters to interrogate regions of myocardium by stimulating and recording with multiple activation patterns. Longitudinal and traverse conduction velocities of the tissue were acquired from the pacing protocol. Artifacts resulting from variable distance between the recording electrodes and pacing site were also detected and removed. This study demonstrates that the mapping o f local tissue properties with variable activation patterns is feasible and can expose features o f the electrophysiological substrate that can not be recovered during sinus conduction.