Evolution of pacing for bradycardias: Sensors

Abstract

A physiological pacing system should be able to restore normal chronotropic response and optimal conduction within and between the atrial and ventricular pacing. Implantable sensors are initially developed to overcome chronotropic incompetence of the sinus node to exercise and non-exercise requirements. Ideal sensor behaviour includes speed of response, proportionality, specificity, and sensitivity. Sensors can be classified by the method they detect a physiological change: body accelerations, paced QRS, impedance and sensors that require special leads. Rate-adaptive pacing is proven to improve exercise capacity and oxygen consumption over fixed-rated pacing, especially during ventricular pacing. Patients with chronotropic incompetence can derive symptomatic benefit in the rate-adaptive mode. The latest development involves the use of sensors to monitor heart failure, and to best optimize rate and conduction status in cardiac resynchronization therapy. © The Author 2007.