Electrical mapping of the heart

ELECTRICAL MAPPING OF THE HEART

FELIX CHIBUZO OBIEmail: [email protected]

SUPERVISED BY ASSO. PROF. DR. CENK CONKBAYIR

FACULTY OF ENGINEERINGDEPARTMENT OF BIOMEDICAL

ENGINEERING

mailto:[email protected]

OUTLINE• INTRODUCTION

• HISTORICAL PERSPECTIVE -Noninvasive Electrical Mapping -Epicardial Mapping -Clinical Endocardial Mapping

• CARTO MAPPING OF CARDIAC CHAMBERS

• ENSITE MAPPING SYSTEM -ENSITE VELOCITY CARDIAC MAPPING SYSTEM -ENSITE VELOCITY SYSTEM COMPONENTS

• CONCLUSION

Electrical Mapping of the Heart-Felix Chibuzo Obi, 2016 2

INTRODUCTION• Electrical mapping of the heart is a medical

procedure that is use to diagnose Arrhythmias in patients. This is done by using sensitive catheter to map the electrical activity in the chambers of the heart.

• To begin an electrical mapping procedure, a thin tube called a catheter sheath is inserted into a small incision in the arm or upper thigh. This process is usually visualized using x-rays and a special dye that helps reveal the arteries (called angiography). This catheter is carefully guided through the blood vessels until it is inside the heart.


HISTORICAL PERSPECTIVE



If 3 leads were good,then 12 leads must be better!

And dozens to hundreds of bodysurface potentials even more useful!

Epicardial Mapping• Initially performed with a limited

number of channels on the epicardial surface.

• Advances in computing power and storage have allowed for thousands of channels of data to be collected simultaneously.


Clinical Endocardial Mapping

• Endovascular catheter mapping reduces invasiveness of mapping techniques

• Many clinically available mapping systems with mapping catheters

• –Carto (Biosense-Webster)• –EnSite NavX (St. Jude Medical)• –Others


CARTO MAPPING OF CARDIAC CHAMBERS• CARTO is a software that creates a

continuous surface map of the chamber depending on the number of mapping points.

• The quality of the map is a reflection of the number of points acquired – the more points, the greater the detail of the map.

• The ‘fill threshold’ is the function that determines the level of interpolation (and hence detail). For detailed maps, the threshold is usually set at 15 units; higher values lead to increased fill and hence a decrease in detail (See next Slide).



Activation map of the RA during typical atrial flutter in left anterior oblique view. Panels show different levels of fill threshold. When low fill threshold is selected (A), acquisition of many other points would be required to construct the anatomy of the atrium. When a higher level of fill threshold is chosen (B, C), the system interpolates activation times between the points and fills blank areas. In such cases,less mapping points are necessary; however, the resulting map is anatomically less precise and activation is more interpolated.

ENSITE MAPPING SYSTEM

• EnSite Mapping System is a Mapping System that Physicians use to create 3-D model of a chamber in the heart. To create the model, patches (called EnSite NavX surface electrode patches) are applied in several places on the body. An electrical signal is transmitted between the patches, and catheters within the heart sense the signal.

• The physician then sweeps the catheter across the heart chamber to outline the structures and relay the signals to the computer system which generates the 3-D model. The diagram from the EnSite NavX helps the physician guide the ablation catheter to the point in the heart where treatment is needed.


ENSITE VELOCITY CARDIAC MAPPING

SYSTEM• EnSite Velocity is the latest released platform of

the EnSite NavX technology.• It enables 3D-Visualisation of multiple

intracardiac Catheters from different Manufactures.

• Fusion algorithms and respiratory compensation allows for model-guided therapy with real-time nonflourescopic visualization of intracardiac Catheters with registered 3D CT/MRI images.

• Currently, this technique represents the preferred approach to study inducible, sustained and hemodynamically tolerated arrhythmias.



Figure 14. 3D entrainment map with EnSite Velocity™ in a patient after previous ablation of persistent atrial fibrillation (pulmonary vein isolation, box lesion, mitral isthmus line) and recurrences of symptomatic macro-re-entrant tachycardia. (A) Persistent isolation of pulmonary veins and the posterior box lesion is shown as scar area (gray) in a posteroanterior projection. (B) Entrainment mapping revealed a perimitral macro-re-entrant tachycardia (color-coded in orange) that terminated after placement of an endocardial mitral annulus line (left anterior-oblique projection)LAO: Left anterior-obique; PA: Posteroanterior

ENSITE VELOCITY SYSTEM

COMPONENTS• The EnSite Velocity Amplifier subsystem consists of the EnSite

Velocity Amplifier and several new modules:

• NavLink

• ArrayLink

• RecordConnect

• CathLink

• GenConnect

• and a SJM ECG Cable.

• The devices accept signals from electrodes attached to or placed in the patient and pass these signals to the EnSite Velocity Amplifier.


Ensite Velocity Amplifier


The amplifier accepts physiologic signals from patient connection modules, converts these signals to a digital format and sends them to the workstation for processing. The EnSite Velocity Amplifier is connected to the workstation through a fiber-optic cable.

Remote Monitor Stand


The Remote Monitor Stand is used for lab configurations that do not have the remote monitor mounted in a boom

These replace: the PIU, with the cabinet-mounted monitor

NavLink


This module connects EnSite™ NavX™ surface electrodes and the System Reference Patch to the EnSite™ Velocity™ Amplifier.

This module replaces:the EnSite NavX patient cable.

EnSite™ NavX™ Surface Electrode Kit


In the EnSite NavX surface electrode kit, the Left Leg patch includes the *EEPROM chip for validation. The built-in chip reduces the potential loss of the loose data module.

*Electrically Erasable Programmable Read-Only Memory

ArrayLink


This module connects the EnSite™ Array™ catheter to the amplifier. The ArrayLink is designed to mount to the patient bedside. The EEPROM chip from the EnSite Array catheter is plugged into the ArrayLink.

This module replaces: the need to have the Breakout Box next to the patient table.

RecordConnect


This module connects a recording system to the EnSite™ Velocity™ Amplifier without the need for jumpers. A different RecordConnect model is required for each manufacturer’s recording system.

CathLink


This module connects diagnostic catheters to the EnSite™ Velocity™ Amplifier. This module is used when a system-specific RecordConnect is not used, and offers a more “generic” means of parallel connections. In order to “share” the intracardiac signals, jumper cables must be used.

This module replaces: the Catheter Input Module. Notice that the first four inputs are no longer restricted to the RF Catheter, and there are no “+” or “-” designations for the polarity of the inputs.

Display Workstation


The Display Workstation Subsystem (DWS) consists of the workstation (computer), monitors, medical grade isolation transformer, video extender, fiber-optic cable and a media converter.

CONCLUSION As for cardiac 3D mapping systems, the CARTO technology

(Biosense Webster, Diamond Bar, CA, USA) is the second widely used approach to localize and visualize an intracardiac catheter in a 3D fashion without the use of fluoroscopy after the EnSite technology. The CARTO system is based on three low-level electromagnetic fields delivered from three separate coils located underneath the patient’s thorax. Using these fields, specialized catheters containing an embedded magnetic sensor can be located in 3D space. The system provides excellent precision in locating the catheter tip with an accuracy of 0.54 ± 0.05 mm. Most recently, the CARTO technology has been widened by implementing current-based 3D catheter localization on top of the underlying sensor-based electromagnetic field localization principle.


REFERENCES• St Jude Medical, EnSite™ Velocity™ Handbook.

• Derek J. Dosdall, Ph.D. Cardiac Arrhythmia Mapping Challenges and Opportunities, 22 October, 2010

• Auricchio A, Fantoni C, Regoli F, et al. Characterization of left ventricular activation in patients with heart failure and left bundle-branch block. Circulation 2004;109:1133–9.

• Callans DJ. How should we evaluate a new technique in a constantly changing world? The Pace and

Ablate study. Heart Rhythm 7(2), 165–166 (2010).

• Cassidy DM, Vassallo JA, Marchlinski FE, et al. Endocardial mapping in humans in sinus rhythm with normal left ventricles: activation patterns and characteristics of electrograms. Circulation 1984;70:37–42.

• Charlotte Eitel†, Gerhard Hindricks, et al. EnSite Velocity cardiac mapping system: a new platform for 3D mapping of cardiac arrhythmias Expert Rev. Med. Devices 7(2), 185–192 (2010)

• De PR, Ho SY, Salerno-Uriarte JA, et al. Electroanatomic analysis of sinus impulse propagation in normal human atria. J Cardiovasc Electrophysiol 2002;13:1–10.

• Durrer D, van Dam RT, Freud GE, et al. Total excitation of the isolated human heart. Circulation 1970;41:899–912.

• Markides V, Davies DW. New mapping technologies: an overview with a clinical perspective. J. Interv. Card. Electrophysiol. 13 (Suppl. 1), 43–51 (2005).

• Osef Kautzner, Anders Kirstein Pedersen and Petr Peichl. Electro-anatomical Mapping of the Heart (An Illustrated Guide to the Use of the CARTO™ System)


Electrical Mapping of the Heart-Felix Chibuzo Obi, 201624

Healthcare

Electrical mapping of the heart