Modeling Patient-Specific Desaturation Patterns in Sleep Apnea.

Objective: The physiological mechanisms involved in cardio-respiratory responses to sleep apnea events are not yet fully elucidated. A model-based approach is proposed to analyse the acute desaturation response to obstructive apneas.

Methods: An integrated model of cardio-respiratory interactions was proposed and parameters were identified, using an evolutionary algorithm, on a database composed of 107 obstructive apneas acquired from 10 patients (HYPNOS clinical study).

Kinesthetic stimulation for obstructive sleep apnea syndrome: An "on-off" proof of concept trial.

Obstructive sleep apnea (OSA) occurs when the upper airway narrows or collapses due to the loss of upper airway muscle activation at sleep onset. This study investigated the effectiveness of triggered kinesthetic stimulation in patients with OSA. This proof-of-concept, open-label, multicenter prospective study was conducted on 24 patients with severe OSA.

Analysis of endocardial acceleration during intraoperative optimization of cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) is the therapy of choice for selected patients suffering from drug-refractory congestive heart failure and presenting an interventricular desynchronization. CRT is delivered by an implantable biventricular pacemaker, which stimulates the right atrium and both ventricles at specific timings. The optimization and personalization of this therapy requires to quantify both the electrical and the mechanical cardiac functions during the intraoperative and postoperative phases.

Endocardial acceleration (sonR) vs. ultrasound-derived time intervals in recipients of cardiac resynchronization therapy systems.

Aims: Optimization of cardiac resynchronization therapy (CRT) requires the gathering of cardiac functional information. An accurate timing of the phases of the cardiac cycle is key in the optimization process.

Methods And Results: We compared Doppler echocardiography to an automated system, based on the recording of sonR (formerly endocardial acceleration), in the detection of mitral and aortic valves closures and measurements of the duration of systole and diastole.

Use of a new cardiac pacing mode designed to eliminate unnecessary ventricular pacing.

Aims: To examine the performance of AAIsafeR2, a new pacing mode to minimize the cumulative proportion of ventricular pacing in patients who do not need regular ventricular support.

Methods And Results: The safety of AAIsafeR2 was examined in 123 recipients (73 +/- 12 years old, 51% men) of dual chamber pacemakers implanted for sinus node dysfunction, paroxysmal AV block or the bradycardia-tachycardia syndrome. Data were collected from pacemaker diagnostics, and the first 43 patients underwent 24-h Holter recordings before being discharged from the hospital with AAIsafeR2 activated.

A new dual-chamber pacing mode to minimize ventricular pacing.

Despite the low long-term incidence of high-degree atrioventricular (AV) block and the known negative effects of ventricular pacing, programming of the AAI mode in patients with sinus node dysfunction (SND) remains exceptional. A new pacing mode was, therefore, designed to combine the advantages of AAI with the safety of DDD pacing. AAIsafeR behaves like the AAI mode in absence of AV block.

Comparison of the cardiopulmonary response to exercise in recipients of dual sensor DDDR pacemakers Versus a Healthy control group.

The authors previously have shown in healthy subjects that age related loss of muscular strength did not alter the chronotropic response during treadmill exercise, whether with sudden onset of effort, as in the chronotropic assessment exercise protocol (CAEP) or more gradual effort as in the Harbor exercise protocol. This study was performed to verify that in patients suffering from chronotropic insufficiency, and in absence of other effort-limiting disorders, "physiologic" pacing enables a cardiorespiratory response comparable to that of age-matched healthy subjects. Furthermore, the aim of the study was to confirm that the response of a new dual sensor-based pacing system was properly adapted to the metabolic demand, whether during CAEP or during Harbor test, by subjecting patients to both protocols.