Wednesday, November 16, 2011

Pacing Without Wires

From Medgadget via The Medical Quack:

EBR Systems, a start-up out of Sunnyvale California, and Cambridge Consultants, the technology design and development firm, have developed a leadless pacemaker system for patients with advanced heart failure. The Wireless Cardiac Stimulation System (WiCS) comprises two units, an implantable electrode and an external control unit. The electrode incorporates an ultrasonic, wireless receiver and delivers an electrical stimulus to the heart based on triggering signals from the external control unit.

In its current iteration the WiCS system is designed to work with conventional pacemakers/defibrillators pacing the right ventricle of patients requiring biventricular pacing. The WiCS external control unit senses the pacing stimulus delivered to the right ventricle and initiates a burst of stimulus from the electrode implanted in the left ventricle. According to the company, the wireless left ventricular pacing approach removes the need for complex surgery and the complications often associated with the coronary sinus leads used to pace the left ventricle.

But to suggest that a left heart catheterization to place their little device in the endocardium of the left ventricle "removes the need for complex surgery" is a stretch. Embolic complications, valvular complications and the potential for stroke complications (with the need for at least some anticoagulation) will quickly temper their enthusiastic press release. And what happens when a patient needs an ultrasound of their heart or has a capsule endoscopy? Could there be significant electromagnetic interference?

But we should not rain on these companies' parade too quickly, even if they are a bit late to the party. The implications of this technology as we move forward with more sophisticated pacing therapies are profound. One only needs to consider complex congenital heart cases with anomalous venous return, epicardial delivery of this technology, or its capability to paired with drug delivery systems in the future to see where things might go with such a novel means of pacing.


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