The Importance of Precise Anatomical Visualization During Interventional EP Procedures

Dr. Saksena, would you please identify the important diagnostic components of the EP procedure?

The initial answer would be the capabilities of the recording and mapping equipment. While those components are absolutely essential, a primary diagnostic tool to position catheters correctly starts with the lab's imaging equipment.

What is important to the electrophysiologist about the room's fluoro imaging equipment?

I am currently using an Integris Allura Biplane X-ray system from Philips Medical Systems in our combination cardiac cath and electrophysiology lab at one of our cardiac centers. The system is used for both coronary interventions and electrophysiology procedures. The biplane system provides great flexibility and ease of use in performing cardiac interventions and various electrophysiology procedures such as atrial fibrillation mapping and ablations, left ventricular ablations, and biventricular pacemaker implants. The biplane configurations are key to visualization of both the atria and ventricular from two angles. Biplane functionality provides the ability to easily perform a transseptal procedure without difficulty. The detail of the image quality and the contrast resolution provide accuracy and speed essential in performing stringent EP procedures today.

How important is image quality versus radiation dose for your patients and clinical staff?

Optimal image quality with the lowest dose rate is critical to patients and the medical staff. Generally, fluoroscopic times are anywhere from 10 to 30 minutes long for routine electrophysiology procedures. Some atrial fibrillation procedures might take up to three or four hours in total procedure time; therefore, dose reduction is a key element of the fluoroscopic equipment. Overall fluoro time has also been reduced by non-contact three-dimensional (3-D) navigation devices and intracardiac ultrasound visualization. Still, the overall fluoro times for the ablation procedures are long. Philips has a unique filtering process incorporating copper in the path of the X-ray beam to reduce the patient dose and scatter to the staff and physician. In some instances, patients are returning with new arrhythmias that require an additional ablation procedure. The continued technological advancement in dose reduction will remain essential criteria when choosing a new X-ray imaging system.

What will be the biggest challenge for the EP vendors in the industry?

Data integration and mining are the key priority needs for electrophysiologists today. Multiple imaging vendors have been concentrating on the data integration for the cardiac cath lab arena, but overlooking the EP department s data needs. Currently, we have to store the information at different locations. This procedure is sometimes cumbersome and time consuming to retrieve the necessary information quickly and easily. I am especially happy to see the partnership between Philips Medical Systems and EP MedSystems the collaboration of technologies will help to provide an integrated solution with built-in storage capabilities.

What other equipment components are important to consider during the EP exam and treatment process?

The recording equipment is another piece of the chain that the clinician will have some personal preferences about; this is a fundamental component that requires some primary technical and clinical attributes in order to provide the patient and physician with the optimal outcome. The recording signal is the key to a good exam. Signal quality is based on the frequency response, signal range and overall baseline noise. Standard recording systems have used differing methods to optimize these parameters in order to have noise free signals; some work better than others. Having an easy to use system is also important; lab staffing can change, and anything that makes the system easy to use is going to help the lab s efficiency and throughput. The stimulator needs to be easy to use and be operated by the clinician operating the workstation. An integrated stimulator makes this possible, and is less work for the clinical staff. The recording system should have good measurement tools. Having a system that is able to automatically measure cycle lengths is a useful tool and a wonderful visual marker for the clinical staff. Some recording systems now have tools that allow the clinician to take baseline measurements with one click of a mouse. Also, the system s database and query engine should be flexible and powerful enough to allow the user to find saved events or information quickly. A 3-D mapping system has become a necessary tool for common and complex EP studies. It is a highly effective tool that helps produce high-quality EP examinations. The mapping system must represent the exact location of the catheters in the heart with a high degree of accuracy. Being able to see multiple catheters in the 3-D reconstruction is especially helpful for the clinician to see a more global view of the anatomy. The mapping system should be able to represent a three-dimensional image of the heart superimposed with color coding indicating local activation time or voltage. This 3-D map allows the EP physician to quickly identify the areas of earliest activation or low voltage or scar areas. Combining both of these qualities insures a quality map and a good patient outcome. Actual integration of the 3-D mapping system to the recording system is also a recent advancement that is very helpful. This allows for bi-directional flow of information between the systems, as well as having one complete record of the EP study. Since room in the lab is usually an issue, a multi-use system with a smaller footprint is especially helpful.

What other things can be done in the lab to see the necessary structures and make life easier for the electrophysiologist?

Intracardiac echocardiography has become exceptionally helpful in EP studies. It has provided the clinician improved capability to precisely place catheters during ablation, to safely perform transseptal punctures, and to see anatomical structures with more detail than ever before. To best understand the patient s anatomy, and to keep the clinicians on the right track, intracardiac echo is a modality that is now coming to the EP lab s attention; it can help reduce procedure times and help the clinician identify complications faster.