Implication of 3D Mapping in EP

Editor's Notes

• #16: The array catheter has a 9 French inner lumen, over-thewiredesign, and a 110 cm usable length.Other catheter features include:• Soft, compliant pigtail tip to reduce trauma. The tip ismade of polyurethane and has a radiopaque marker.• Balloon inflation port to inflate and deflate the arrayballoon.• Hemostasis valve with a sideport for flushing thecatheter during use.• Positive gripping mechanism (PGM) to grip thecentral catheter shaft.• 96-pin connector that connects to the BOB.• Data module that includes the number, status, andexact location of each array electrode. Electrode datais unique for each catheter and is established duringmanufacture. The array is functional with up to eightdisabled electrodes.
• #18: The EnSite System uses the chamber geometry to solve theinverse problem for Laplace’s equation at 64 locations onthe geometry surface. The process creates an isopotentialmap surface with more than 3000 virtual EGMs.• The Laplace equation states that if the voltages measuredon an outer boundary (endocardium) are known, voltageseverywhere inside the chamber can be calculated.− The potential field at any one electrode (pointshown) is influenced by electrical potentials fromthe entire endocardium, with the degree of influencediminishing as distance between the electrode andeach endocardial point increases.− The potential field created on the multielectrode array(MEA) surface depends on the shape of the MEA andendocardium as well as their locations relative to oneanother.• Using the known information about the MEA, chambergeometry, and position and distance of the MEA relativeto the endocardial surface, the EnSite System canconstruct endocardial EGMs (virtuals) from MEApotentials.
• #24: R and Z values identify the position of the multielectrodearray (MEA) relative to the located electrode on a roving EPcatheter – called the Active EnGuide. These values serve ascoordinates for optimizing the position of the MEA within achamber.• The R value is the distance in millimeters from the activeelectrode to the center of the MEA.• The Z value is the distance in millimeters of the activeelectrode above or below the MEA equator. The Zvalue is negative if the active electrode is distal the MEAequator and positive if it is proximal to the MEA equator.Note: The R and Z values are displayed in the lower portionof the map. The Active EnGuide is setup at the start of a newstudy (see CheckWizard).
• #27: The EnGuide catheter is a user-selected contact catheterused to collect location information, build the chambergeometry, and place anatomic and lesion markers. TheEnGuide locator displays the position of the EnGuidecatheter relative to the position of the E1 and E2 electrodes ofthe MEA.
• #30: Virtual EGMs display the direction and velocity ofcardiac activation and confirm the site of earliest activation(arrhythmia origin) in the cardiac chamber.• Virtuals are mathematically constructed from voltagemeasurements and plotted as amplitude (verticalaxis) vs. time (horizontal axis). When positioned onthe isopotential map, virtuals verify map color duringdepolarization and are useful in characterizing anarrhythmia.• The tracking virtual is a virtual EGM that automaticallytravels to the most negative location on the map in stepwith the time cursor. The tracking virtual is the red iconwithin the white area of the map. The computed trackingvirtual EGM is displayed in the lower righthand cornerof the map.
• #40: The EnSite System can be used with surface electrodepatches to navigate conventional EP catheters to criticalintracardiac sites, without using fluoroscopy. This techniqueis called contact mapping.Using the surface electrodes, the EnSite System:• Collects, records, and displays surface ECG andintracardiac EGM waveforms.• Locates and displays up to 64 EP catheter electrodes inthe cardiac chamber. The location information is usedto navigate EP catheters. It can also be used to createa chamber geometry and place anatomic labels, lesionmarkers, and EnGuide shadows.
• #41: Contact mapping works by creating an electrical fieldbetween opposing pairs of surface patch electrodes to locateand display an EP catheter in 3D space.
• #43: EnSiteNavX enables physicians to visualize and navigate a myriad of intracardiac catheters in any chamber of the heart. It also simultaneously displays more electrodes and catheters than any other 3-D mapping system currently available.EnSiteNavX is compatible with catheters from all manufacturers. The non-proprietary nature of our technology gives you freedom of choice for diagnostic and ablation catheters.
• #45: Respiration Compensation helps minimize the effects ofrespiration during contact mapping studies. It may facilitatemore consistent geometry creation and lesion marking andimproves navigation stability while placing lesions.During Respiration Compensation, the cardiac mappingsystem:• Instructs the clinician to leave all catheters in relativelystable positions.• Collects the x-y-z coordinates of all electrodes andimpedance values of all surface electrodes over a tensecondsampling period.• Identifies respiration through the surface electrodes as agradual rise in intrathoracic impedance and correlates thisrise with a motion artifact on each electrode.• Monitors surface electrodes for the impedance pattern.When respiration occurs, navigation on each electrode iscompensated gradually, in correlation with the degree ofthe impedance change.The cardiac mapping system accommodates changes inrespiration during sampling. Respiration Compensationcan be recalculated any time and is recommended afteradding electrodes, significantly moving the catheter, or whenrespiration motion is still visible.
• #47: Figure 3. The 3D lesions (actual lesion positions in 3D space) are shown in the upper panels and the surface lesions (projected onto the CT surface) are shown in the lower panels for a patient undergoing left atrial pulmonary vein (PV) circumferential ablation. Panels (A) and (E) show the lesion sets around both PV pairs, (B) and (F) around the left PVs, and (C) and (G) around the right PVs. Panels (D) and (H) show the same orientations as panels (C) and (G) but with the NavX geometry overlaid onto the CT (without any transparency). The close approximation of the NavX geometry and CT can be appreciated, as well as the relationship of the lesion rings to both. The circumferences of the 3D and surface lesion rings were calculated as described in the main text, and the values compared as a measure of accuracy of geometry/CT integration. A single catheter can be seen in the LA in panels (B) and (F).
• #51: 少女與老婦人
• #52: 這種現像在心理學上叫做“非注意盲視（inattential blindness）”，當你全神貫注於某一個問題時，往往會忽視另外一個顯而易見，或是平時會很引人注目的地方。圖中的12指男人是來自古巴的Yoandri Hernandez Garrido，他每個手都有6個手指，每隻腳也各有6個腳趾。