Closed loop stimulation in prevention of vasovagal syncope. Inotropy Controlled Pacing in Vasovagal Syncope (INVASY): a multicentre randomized, single blind, controlled study.

Objectives: To determine whether dual-chamber rate-adaptive Closed Loop Stimulation (CLS) could prevent recurrence of Vasovagal Syncope (VVS).

Background: During VVS, an increase in myocardial contractility associated with a reduction of ventricular filling produces an increase in baroreceptor afferent flow and a consequent decrease in the heart rate. The CLS algorithm is a form of rate-adaptive pacing, which responds to myocardial contraction dynamics, by measuring variations in right ventricular intracardiac impedance: during an incipient VVS it could increase paced heart rate and avoid bradycardia, arterial hypotension and syncope.

A new algorithm for closed-loop stimulation: a feasibility study.

Closed-loop stimulation (CLS) is a physiological system for adaptive rate pacing based on monitoring and processing of the intracardiac impedance. The "standard" CLS algorithm (SCLS) requires continuous ventricular pacing. A new, enhanced CLS algorithm (ECLS) provides rate modulation during sensed and paced ventricular depolarizations.

[Long-term clinical assessment of single-lead VDD electric stimulation].

Background: During the last decade single lead VDD pacing has been progressively affirmed as an electrotherapy of choice in patients with advanced atrioventricular block without alterations of the sinus function. It combines the benefits of P-synchronous ventricular pacing with an easy implant procedure when compared to the conventional DDD approach. The aim of this study was to evaluate the validity of such an approach in a large population of patients, all implanted in a single center.

A new approach to the prevention of endless loop tachycardia in DDD and VVD pacing.

Endless loop tachycardia (ELT) is a possible complication in dual chamber pacing; it is usually prevented by programming the atrial refractory period (PVARP) longer than the retrograde ventriculoatrial (VA) conduction interval; this in some patients limits the upper rate. In 15 patients with a DDD (nine patients) or a single-pass lead VDD pacemaker (six patients) and retrograde atrial activation, telemetric recording documented a significant difference in amplitude of antegrade, and retrograde atrial potentials (VDD 1.21 +/- 0.

A new single lead VDD pacing system.

In 24 patients with advanced heart block and normal sinus node function, a new single lead VDD pacing system was implanted. At implantation, the endoatrial, bipolar electrogram was recorded in all patients. The lead position was checked by means of chest X-ray.

[Technology and real performances of a new circuit for new pacemaker (author's transl)].

Continuing evolution in cardiac stimulation today imposes on PM manufacturers the need to submit their products under new criteria, such as: contained dimensions, functional complexity and longer periods of patient care. PM electronic circuity plays a determinant role in meeting the best solution of these problems. Thick film hybrid technology has been chosen by the Authors because it is deemed to be the best compromise for the present goals, such as: low power consumption, low weight and small size, electrical parameters stability, functional complexity and high circuitry density, Hi-Rel performance for longer working life.