A Medical Device Daily

ELA Medical (Arvada, Colorado), a business of the Sorin Group (Milano, Italy) that develops cardiac rhythm management and diagnostic systems, used this year’s edition of the Heart Rhythm Society’s (HRS; Washington) 2005 annual meeting in New Orleans to banner FDA clearance for its AAIsafeR 2 pacing mode, a second-generation technology designed to prevent unnecessary ventricular pacing.

ELA terms the AAIsafeR 2 “the first therapeutic pacing alternative available in the U.S.” and said that its Symphony pacemakers with AAIsafeR 2 limit unnecessary ventricular stimulation to 0.1% in patients while they are not in heart block, meaning an electrical disturbance that blocks the heart’s in-sync pumping.

“Conventional pacemakers unnecessarily pace these same individuals 50% to 80% of the time,” ELA said, adding that recent studies indicate that unnecessary right ventricular pacing increases the risk of developing heart failure and atrial fibrillation (AF).

The company said the new pacing mode potentially could benefit more than 300,000 people in the U.S. who receive a dual-chamber pacemaker, or about 60% of the pacemaker population. “No other pacemaker can treat such a large patient population,” it said.

ELA’s first-generation AAIsafeR technology was launched in its Symphony pacing systems in Europe in September 2003, and the company received CE marking for its AAIsafeR 2 technology earlier this year.

Malcolm Bersohn, MD, PhD, electrophysiologist and professor of medicine at the University of California Los Angeles Medical Center, said, “AAIsafeR 2 will offer a dramatic reduction in ventricular pacing for a high percentage of patients” and comes “remarkably close” to achieving the goal of zero-percent unnecessary pacing.

The AAIsafeR 2 pacing mode is already incorporated in previously implanted Symphony pacemakers. A software change to the pacemaker programmer unlocks this feature in patients who already have these devices implanted.

ELA will hold a satellite symposium discussing the AAIsafeR pacing mode this morning.

A fairly large presence at Heart Rhythm 2005 is the increasing use of robotic technologies for percutaneous cardiovascular procedures.

Hansen Medical (Mountain View, California) is showcasing its new system combining computed movement with robotic technology, enabling physicians to control the navigation of catheters within the heart to treat heart rhythms.

The Hansen Catheter Control System (CCS) is designed to provide 3-D navigation for accessing hard-to-reach anatomy, while maintaining stability during treatment of cardiac arrhythmias such as AF.

With the trend of movement from open surgical procedures to percutaneous procedures, Hansen says that its CCS provides an additional tool improving the control needed in the percutaneous strategy. “To date, a majority of clinicians continue to manually guide catheters through the heart to detect and treat a variety of cardiac arrhythmias, despite the lack of precision offered by these catheters,” Hansen said.

CCS is the first technology, Hansen said, “to combine computed movement with an electromechanically controlled catheter, with the system then integrated into a workstation that can be placed away from radiation exposure.”

The CSS has not yet been FDA-cleared.

Preclinical studies for the Hansen CCS were designed to evaluate the ability of the guide sheath and steerable guide catheter to remotely navigate an ablation catheter to a series of anatomical targets in the right and left atria, as well as placement of radio frequency (RF) ablation lesions and control of 3-D surface-mapping catheters.

Andrea Natale, MD, director of the Electrophysiology Lab and co-section head of Pacing and Electrophysiology at the Cleveland Clinic Foundation (Cleveland), said, “During preclinical trials, this novel, robotic control system demonstrated that control and placement of cardiac catheters through a steerable guide catheter could be accomplished.”

She added: “To have precise control of an ablation catheter in a flexible and simple platform for navigation within the cardiac chambers, and to be able to achieve this from a remote location could make ablation of complex arrhythmias, including [AF] significantly easier and more feasible for all clinicians.”

A key CCS feature is an electromechanical catheter manipulator, which responds to commands a physician inputs from a workstation compatible with imaging modalities such as fluoroscopy, ultrasound and 3-D surface maps.

The CCS is being developed initially for electrophysiology and interventional cardiology, with the company exploring expanded applications in neurovascular, peripheral vascular and other endoluminal body cavity applications.

In other product news from Heart Rhythm 2005:

• Stereotaxis (St. Louis) also is featuring its computer-controlled magnetic navigation technology in a flood of presentations: 12 presentations at four symposiums, three poster sessions, three oral abstract sessions, a case-based tutorial, and a presentation during the core curriculum portion of the conference. Electrophysiologists from both Europe and the U.S. are presenting their views on experiences relating to mapping and ablation, cardiac resynchronization therapy and other applications of the Stereotaxis Niobe Magnetic Navigation System.

The Stereotaxis System is designed to enable physicians to complete more complex interventional procedures by providing image guided delivery of catheters and guidewires through the blood vessels and chambers of the heart to treatment sites.

Since one of Stereotaxis’ technology partners, Biosense Webster (Diamond Bar, California), received CE mark approval for its Celsius RMT and NaviStar RMT ablation catheters and the Carto RMT navigation and ablation system at the end of the first quarter, the company said its Niobe technology has seen frequent clinical use in Europe: more than 100 procedures completed, an average of one per day by those sites that have installed both the Stereotaxis system and the Biosense Carto RMT navigation and ablation system. These ablation catheters are not currently available in the U.S.

Stereotaxis said recent procedures being performed in Europe include successful treatment of cardiac resynchronization therapy through placement of bi-ventricular pacing leads; several forms of supraventricular tachycardia, including AV node reentry tachycardia, atrial flutter and Wolff-Parkinson-White syndrome; and the treatment of AF.

• Siemens Medical Solutions (Erlangen, Germany/Malvern, Pennsylvania) is featuring the launch of enhancements to its Axiom Sensis hemodynamic and electrophysiological (EP) recording system. Customers already using the Axiom Sensis for EP, Siemens said, will automatically receive the software upgrades which feature several new applications, such as vital signs logging, non-invasive blood pressure measurements, arrhythmia detection and recording, examination archiving, and Axiom Sensis data transfer between two systems.

Siemens also will highlight the AcuNav 8F catheter, enabling improved access in all patients, particularly small-er patients and for left heart applications in EP and interventional cardiology. The new catheter is sized at 8 Fr and is 33% smaller in the cross sectional area than the existing Acuson AcuNav 10F catheter.

According to clinical evaluators, Siemens said, “the smaller size coupled with the same performance as the AcuNav 10F catheter is a significant improvement and allows access to a wider range of patients.”

Additionally, the company is showcasing the Acuson CV70 cardiovascular ultrasound system with Doppler sensitivity, color flow sensitivity and spatial resolution. Featuring foursight transesophageal (TEE) view for integrated 3-D TEE imaging, and P9-4 transducer for pediatric cardiac imaging, the system enables easier access to 3-D/4-D images through simple acquisition, review, manipulation and display capabilities of 3-D datasets using the V5Ms TEE transducer.