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Novel implantable defibrillators (ICDs) allow first (S1) and third (S3) heart sounds to be measured by means of an embedded accelerometer. ICD-measured S1 and S3 have been shown to significantly correlate with hemodynamic changes in acute animal models. The HeartLogic algorithm (Boston Scientific) measures and combines multiple parameters, including S3 and S1, into a single index to predict impending heart failure decompensation. We evaluated the echocardiographic correlates of ICD-measured S1 and S3 in patients with ICD and cardiac resynchronization therapy ICD.The HeartLogic feature was activated in 104 patients. During in-office visits, patients underwent echocardiographic evaluation, and parameters of systolic and diastolic function were correlated with S3 and S1 amplitude measured on the same day as the visit.S3 amplitude inversely correlated with deceleration time of the E-wave (r = -0.32; 95% CI -0.46 - -0.17; P 0.001), and S1 amplitude significantly correlated with left ventricular ejection fraction (r = 0.17; 95% CI 0.03-0.30; P = 0.021). S3 0.9 mG detected a restrictive filling pattern with 85% (95% CI 72%-93%) sensitivity and 82% (95% CI 75%-88%) specificity, while S1 1.5 mG detected ejection fraction35% with 28% (95% CI 19%-40%) sensitivity and 88% (95% CI 80%-93%) specificity.ICD-measured heart sound parameters are significantly correlated with echocardiographic indexes of systolic and diastolic function. This confirms their utility for remote patient monitoring when used as single sensors and their potential relevance when considered in combination with other physiological ICD sensors that evaluate various aspects of heart failure physiology.

Ritme cardíac; Síncope reflex neurològic; Prova de la taula d’inclinació Ritmo cardíaco; Síncope reflejo neuromediado; Prueba de la mesa inclinada Cardiac pacing; Neuro-mediated reflex syncope; Tilt-Table test Background: The efficacy of dual-chamber cardiac pacing in neuro-mediated reflex syncope with a cardio-inhibitory response to the Tilt-Table test (TT) has not been definitively assessed so far. The lack of reproducibility of results from previous studies may be partially explained by discrepancies in subject selection and some weaknesses in design and methods. The European Society of Cardiology (ESC) has set a class IIb indication to pacemaker implantation in this population recommending further research. Methods/design: The BIOSync study is a multicenter, patient- and outcome-assessor-blind, randomized, parallel-arm, placebo-controlled trial with the objective of assessing the clinical benefit of cardiac pacing in patients with frequently recurrent reflex syncope, suspected (but not proven) to be triggered by asystolic pauses as showing a VASIS 2B response to the TT (>3-s pause regardless of blood pressure drop). The primary and secondary endpoints are time to first post-implantation recurrence of syncope or the combination of pre-syncope or syncope, respectively. One hundred and twenty-eight consenting patients will be 1:1 randomized to dual-chamber cardiac pacing 'on' or 'off' after pacemaker implantation, and followed up until the first adjudicated primary endpoint event for a maximum of 2 years. The so-called Closed Loop Stimulation function on top of dual-chamber pacing is the pacing mode selected in the study active arm. Participating patients are asked to self-report syncopal symptoms at least every 3 months with self-administered questionnaires addressed to an independent Adjudication Committee. Patients and members of the Adjudicating Committee are blinded to randomization. The study is designed to detect a 40% relative reduction in the 2-year incidence of syncopal recurrences with 80% statistical power. Discussion: The BIOSync study is designed to definitively assess the benefit of pacing against placebo in reflex syncope patients with a cardio-inhibitory response to the TT. The study will also provide important information on the efficiency of the TT in appropriately selecting reflex syncope patients for cardiac pacing. All study-related costs are being directly supported by the sponsor of the study (BIOTRONIK SE & Co. KG, Berlin, Germany). No further funding is provided.

Background.Discomfort related to low-energy internal cardioversion (LEIC) represents a real problem in patients (pts) with atrial fibrillation (AF). The aim of our study was to verify if a single shock could restore sinus rhythm (SR) with a lower discomfort for the pt. Methods. Thirty pts with chronic AF were randomized to receive a single 350 V shock (15 pts) or multiple shocks of increasing energy (15 pts). Three leads were positioned, respectively, in the coronary sinus and in the lateral right wall for shock delivery, and in the right ventricular apex for R wave synchronization. Truncated, biphasic shocks were used. In the first group a single 350 V shock was directly delivered and a second 400 V shock was given only if SR has not been restored. In the second group, beginning at 50 volts the voltage was increased in steps of 50 volts until SR restoration. No patient was sedated. After each shock the pts were asked to rate their discomfort on a scale of 1 to 5 (1 = not perceived, 5 = severe discomfort) Results. SR was restored in all the subjects. In group 1 SR was obtained in 12/15 (80%) pts with the first 350 V (8.1±0.8 joules) shock, while the remaining 3 patients required the second 400 V (10.2±10.3 joules) shock. In group 2 the mean atrial defibrillation threshold was 346.7±29.7 volts (8.0±1.5 joules). Then discomfort score was 2.5±0.6 in group 1 and 3.3±0.6 in group 2 (p < 0.01). Conclusions. A single shock of 350 V restores SR in the majority of pts with chronic AF; by use this new approach, LEIC is tolerated better than the multiple shocks step-up protocol.