Heart rate differences between symptomatic and asymptomatic Brugada syndrome patients at night.

OBJECTIVE: Ventricular arrhythmias in Brugada syndrome (BS) mainly occur at rest, especially during nighttime, suggesting that parasympathetic activity at night may play an important role in the arrhythmogenesis of the disease. This study examined and compared the autonomic function of symptomatic and asymptomatic BS patients overnight. APPROACH: We analyzed various heart rate variability (HRV) and heart rate complexity (HRC) markers in a clinical series including 87 BS patients, where 23 were symptomatic. MAIN RESULTS: Statistically significant differences were found in markers MIRR, SDNN, SDANN, [Formula: see text] and SampEn, suggesting that symptomatic patients may be related to lower heart rate variability and complexity values, as well as to greater circadian fluctuations overnight. SIGNIFICANCE: The results provide further evidence for the role of autonomic imbalance in the pathophysiology of BS, highlighting the relevance of nighttime analysis to the unmasking of significant ANS changes. Based on these outcomes, the role of HRV and HRC assessment at night could be a step forward towards the understanding of BS and the risk for the occurrence of symptoms in these patients, with a potential future impact on therapeutic strategies.

Heart rate complexity analysis in Brugada syndrome during physical stress testing.

Symptoms such as ventricular arrhythmias in Brugada syndrome (BS) typically occur at rest, especially during sleep, suggesting that the autonomic nervous system (ANS) function may be relevant in the arrhythmogenesis of the disease. The aim of this work was to assess the ANS response captured by nonlinear heart rate variability (HRV) measures in 69 patients diagnosed with BS, who underwent a standardized physical stress test. Heart rate complexity (HRC) was evaluated by the power-law scaling analysis (ß slope) during rest, exercise, recovery and rest post-recovery, in order to discriminate between symptomatic and asymptomatic BS patients. Symptomatic patients showed a significant reduction in HRC in comparison to asymptomatic subjects, after exertion (p = 0.015); during the whole recovery period (p = 0.023), and in particular within the passive recovery phase (p = 0.025), as well as during rest post-recovery (p = 0.022). Based on these results, symptoms could be associated with a lower ANS complexity during the stress test stages where parasympathetic activity is predominant. Therefore, the proposed HRV indicators could be of help in the risk stratification of asymptomatic patients.

Prognostic value of left atrial reservoir function in patients with severe aortic stenosis: a 2D speckle-tracking echocardiographic study.

AIMS: The aim of this article is to assess the left atrial (LA) reservoir function in patients with severe aortic stenosis (AS) and to evaluate its impact on the recurrence of major adverse cardiac events (MACEs). METHODS AND RESULTS: About 128 patients (mean age 79 ± 9 years) with severe AS were included in the study. Global peak LA strain (PLAS) measured by two-dimensional speckle-tracking echocardiography (STE) during left ventricular (LV) systole represented the LA reservoir function. Overall death, hospitalization for cardiac cause, and worsening heart failure were defined as MACEs. With respect to the values observed in a control group of 20 healthy patients, PLAS resulted significantly reduced in AS. According to the multivariate linear regression analysis, LV global longitudinal strain, mitral E/e' ratio, and systolic pulmonary arterial pressure (sPAP) were the best correlates to PLAS. During follow-up, the predefined MACEs occurred in 39 patients. According to the multivariate Cox regression analysis, a PLAS <21% was a significant predictor of MACEs [hazard ratio (HR) 2.88, P = 0.04], as was coronary artery disease (HR 2.68, P = 0.004) and the New York Heart Association functional class (HR 2.08, P = 0.03). CONCLUSION: In patients with severe AS, a global PLAS <21% is an independent predictor of prognosis. Given the combined influence of LV diastolic and systolic function and of LA performance on sPAP, the decline of PLAS might be considered a marker of global myocardial impairment in AS. Further studies are needed to confirm the critical role of LA relaxation in prognosis and to validate its relevance in routine clinical practice.

Are electronic cardiac devices still evolving?

OBJECTIVES: The goal of this paper is to review some important issues occurring during the past year in Implantable devices. METHODS: First cardiac implantable device was proposed to maintain an adequate heart rate, either because the heart's natural pacemaker is not fast enough, or there is a block in the heart's electrical conduction system. During the last forty years, pacemakers have evolved considerably and become programmable and allow to configure specific patient optimum pacing modes. Various technological aspects (electrodes, connectors, algorithms diagnosis, therapies, ...) have been progressed and cardiac implants address several clinical applications: management of arrhythmias, cardioversion / defibrillation and cardiac resynchronization therapy. RESULTS: Observed progress was the miniaturization of device, increased longevity, coupled with efficient pacing functions, multisite pacing modes, leadless pacing and also a better recognition of supraventricular or ventricular tachycardia's in order to deliver appropriate therapy. Subcutaneous implant, new modes of stimulation (leadless implant or ultrasound lead), quadripolar lead and new sensor or new algorithm for the hemodynamic management are introduced and briefly described. Each times, the main result occurring during the two past years are underlined and repositioned from the history, remaining limitations are also addressed. CONCLUSION: Some important technological improvements were described. Nevertheless, news trends for the future are also considered in a specific session such as the remote follow-up of the patient or the treatment of heart failure by neuromodulation.

Patient perspective on remote monitoring of cardiovascular implantable electronic devices: rationale and design of the REMOTE-CIED study.

BACKGROUND: Remote patient monitoring is a safe and effective alternative for the in-clinic follow-up of patients with cardiovascular implantable electronic devices (CIEDs). However, evidence on the patient perspective on remote monitoring is scarce and inconsistent. OBJECTIVES: The primary objective of the REMOTE-CIED study is to evaluate the influence of remote patient monitoring versus in-clinic follow-up on patient-reported outcomes. Secondary objectives are to: 1) identify subgroups of patients who may not be satisfied with remote monitoring; and 2) investigate the cost-effectiveness of remote monitoring. METHODS: The REMOTE-CIED study is an international randomised controlled study that will include 900 consecutive heart failure patients implanted with an implantable cardioverter defibrillator (ICD) compatible with the Boston Scientific LATITUDE® Remote Patient Management system at participating centres in five European countries. Patients will be randomised to remote monitoring or in-clinic follow-up. The In-Clinic group will visit the outpatient clinic every 3-6 months, according to standard practice. The Remote Monitoring group only visits the outpatient clinic at 12 and 24 months post-implantation, other check-ups are performed remotely. Patients are asked to complete questionnaires at five time points during the 2-year follow-up. CONCLUSION: The REMOTE-CIED study will provide insight into the patient perspective on remote monitoring in ICD patients, which could help to support patient-centred care in the future.

Optimal algorithm switching for the estimation of systole period from cardiac microacceleration signals (SonR).

Previous studies have shown that cardiac microacceleration signals, recorded either cutaneously, or embedded into the tip of an endocardial pacing lead, provide meaningful information to characterize the cardiac mechanical function. This information may be useful to personalize and optimize the cardiac resynchronization therapy, delivered by a biventricular pacemaker, for patients suffering from chronic heart failure (HF). This paper focuses on the improvement of a previously proposed method for the estimation of the systole period from a signal acquired with a cardiac microaccelerometer (SonR sensor, Sorin CRM SAS, France). We propose an optimal algorithm switching approach, to dynamically select the best configuration of the estimation method, as a function of different control variables, such as the signal-to-noise ratio or heart rate. This method was evaluated on a database containing recordings from 31 patients suffering from chronic HF and implanted with a biventricular pacemaker, for which various cardiac pacing configurations were tested. Ultrasound measurements of the systole period were used as a reference and the improved method was compared with the original estimator. A reduction of 11% on the absolute estimation error was obtained for the systole period with the proposed algorithm switching approach.

Early and late cardiac ventricular reverse remodeling after catheter ablation for lone paroxysmal atrial fibrillation.

AIM: We sought to explore ventricular function in patients with lone paroxysmal atrial fibrillation (AF) and determine the mid- and long-term impact of pulmonary vein isolation on cardiac remodeling. BACKGROUND: The relationship between tachyarrhythmia and ventricular dysfunction is still a matter of debate. Tachycardia-induced cardiomyopathy is defined as reversible myocardial dysfunction following treatment for tachyarrhythmia. METHOD: We prospectively studied 31 patients (56.4 ± 10 years) presenting with paroxysmal-AF who were treated successfully by catheter ablation and 15 age-matched controls. Left and right ventricular functions were assessed by echocardiography at baseline and at 3-month and 1-year follow-up. RESULTS: In AF-patients, LV-function was slightly lower at baseline than controls (LV-ejection fraction was 60% versus 64%; P = 0.06). More impressive, systolic peak velocity on Doppler tissue imaging was 9 cm/s in AF patients (versus 12 cm/s; P = 0.0004). LV global longitudinal strain was also significantly different between the two groups (patients: -16% versus controls: -19%; P = 0.005). At 1-year follow-up, most functional parameters significantly improved in the AF-patients and no longer differed from the controls. Right ventricular (RV) function was also depressed in AF patients at baseline. At 1-year follow-up, tissue Doppler showed improvement in RV-S' (+27%, P = 0.007) and RV peak systolic strain (+36%, P<0.0001) and became comparable to controls. CONCLUSION: We demonstrate that some degree of arrhythmic cardiomyopathy exists in patients presenting with lone paroxysmal-AF. Catheter ablation improved RV and LV functions. Longitudinal function is the most sensitive component of ventricular systole to monitor when looking for this cardiac reverse remodeling.

Long-term prognosis of patients diagnosed with Brugada syndrome: Results from the FINGER Brugada Syndrome Registry.

BACKGROUND: Brugada syndrome is characterized by ST-segment elevation in the right precordial leads and an increased risk of sudden cardiac death (SCD). Fundamental questions remain on the best strategy for assessing the real disease-associated arrhythmic risk, especially in asymptomatic patients. The aim of the present study was to evaluate the prognosis and risk factors of SCD in Brugada syndrome patients in the FINGER (France, Italy, Netherlands, Germany) Brugada syndrome registry. METHODS AND RESULTS: Patients were recruited in 11 tertiary centers in 4 European countries. Inclusion criteria consisted of a type 1 ECG present either at baseline or after drug challenge, after exclusion of diseases that mimic Brugada syndrome. The registry included 1029 consecutive individuals (745 men; 72%) with a median age of 45 (35 to 55) years. Diagnosis was based on (1) aborted SCD (6%); (2) syncope, otherwise unexplained (30%); and (3) asymptomatic patients (64%). During a median follow-up of 31.9 (14 to 54.4) months, 51 cardiac events (5%) occurred (44 patients experienced appropriate implantable cardioverter-defibrillator shocks, and 7 died suddenly). The cardiac event rate per year was 7.7% in patients with aborted SCD, 1.9% in patients with syncope, and 0.5% in asymptomatic patients. Symptoms and spontaneous type 1 ECG were predictors of arrhythmic events, whereas gender, familial history of SCD, inducibility of ventricular tachyarrhythmias during electrophysiological study, and the presence of an SCN5A mutation were not predictive of arrhythmic events. CONCLUSIONS: In the largest series of Brugada syndrome patients thus far, event rates in asymptomatic patients were low. Inducibility of ventricular tachyarrhythmia and family history of SCD were not predictors of cardiac events.

[Magnetic resonance imaging in patients with pacemakers and implantable cardioverter-defibrillators: a systematic review]. / Imagerie par résonance magnétique chez les patients porteurs de stimulateurs cardiaques et de défibrillateurs automatiques implantables: revue de la littérature.

The presence of a pacemaker or an implantable cardioverter-defibrillator was historically considered a contraindication to magnetic resonance imaging (MRI), due to the risks for both patient and device: reed-switch closure responsible for asynchronous pacing, inhibition of pacing, rapid ventricular pacing, heating on the lead tip or even device displacement... However, many recent studies demonstrate that if MRI is crucial for the management of the patient, it can be performed under specific monitoring and scanning conditions and after device reprogramming. The growing implication of device constructors in constructing a MRI safety device will perhaps extend in the future the indications of this imaging modality in implanted patients.

An original defibrillation lead implantation to avoid tricuspid prosthesis damage.

We report the case of a 67-year-old woman suffering from Ebstein's disease, who underwent three cardiac operations for bypass, tricuspid prosthesis and pacemaker implantation, and who needed an implantable cardioverter defibrillator for recurrent syncopes related to ventricular tachycardia. Because of the tricuspid prosthesis we chose to implant the defibrillation lead in the inferior vena cava. We collected satisfactory pacing and sensing data and performed a successful defibrillation test during the procedure. This configuration appears to be a safe alternative to conventional implantation in the coronary sinus, as already described in the literature for a few cases.

[Cough syncope caused by a possible Chlamydia pneumoniae pneumonia]. / Ictus laryngé au cours d'une possible pneumopathie à Chlamydia pneumoniae.

We report the case of a 61-year-old man who presented with coughing fits followed by sinus pauses and syncope. Cardiac and neurological diagnostic work-up was negative and the patient was considered to have cough syncope. As this occurred within the context of febrile pneumonia, an infectious disease was suspected but diagnostic work-up only revealed an increase of antibodies against Chlamydia pneumoniae. The responsibility of this agent is discussed. Clinical recovery was obtained with the prescription of antitussive medication.

[Management of atrial fibrillation in France: the observational FACTUEL study]. / Fibrillation atriale, description de la prise en charge par les cardiologues, étude observationnelle. Résultats de l'étude Factuel.

OBJECTIVES: To describe the management of patients with atrial fibrillation (AF) and to study consistency with guidelines on management of AF. PATIENTS AND METHODS: Observational study on a random sample of cardiologists from a French national database. Each cardiologist had to recruit the first five patients meeting inclusion criteria (patients diagnosed with AF between January 2004 and one month before inclusion and accepting the collection of their medical data). RESULTS: Between December 2006 and January 2207, 1789 patients aged 71 on average have been recruited by 481 cardiologists. Fifty-one percent were diagnosed with paroxysmal, 15% with persistent and 33% with permanent AF. Restoration of sinus rhythm was preferred in forms considered as paroxysmal or persistent forms whereas control of the ventricular rate was more frequent in AF considered as permanent. Overall, therapeutic guidelines are applied in practice, despite a frequent use of amiodarone in patients with no associated heart disease. Prevention of thromboembolism was observed in 88% of the patients. CONCLUSIONS: FACTUEL is the biggest observational study on AF ever conducted in France. The therapeutic strategies used by the cardiologists are consistent with the objectives of preventing thromboembolism and controlling heart rhythm and/or rate. In most cases, the treatment used is consistent with the therapeutic guidelines.

[Long QT syndrome: an underestimated cause of sudden infant death]. / Le syndrome du QT long congénital : une cause sous-estimée de la mort subite inexpliquée du nourrisson.

Congenital long QT syndrome (LQTS) is an inherited arrhythmia that can be sporadic or familial. It predisposes to sudden cardiac death by ventricular fibrillation, which can occur at any age, particularly in neonates. Recent postmortem molecular screening surveys have shown that 10 to 12% of sudden infant death syndrome (SIDS) cases were potentially related to congenital long QT syndrome. Current SIDS etiological surveys fail to diagnose LQTS. Specific questioning and electrocardiographic screening of first-degree relatives could greatly facilitate LQTS diagnosis. We propose adding these to screening modalities after a SIDS incident. Neonatal electrocardiographic screening could allow early identification of LQTS and adapted treatment and follow-up.

Can peripartum cardiomyopathy be familial?

Peripartum cardiomyopathy (PPCM) is a rare disorder, with four principal features: 1--development of cardiac heart failure in the last month of pregnancy or within five months after delivery, 2--absence of an identifiable cause for heart failure, 3--absence of underlying heart disease prior to the last month of pregnancy, 4--evidence of left ventricular systolic dysfunction by classic echocardiographic criteria. Reported forms of familial peripartum cardiomyopathy are exceptional. Our observation emphasizes the interest of cardiac magnetic resonance imaging (MRI) in the investigation of an acute heart failure occurring during the peripartum and allows us to evoke a genetic predisposition in some cases of PPCM, to discuss the fact that some forms of familial PPCM could be unknown familial dilated cardiomyopathy unmasked by pregnancy, and to wonder on the familial screening modalities.

Clustering follow-up time-series recorded by cardiac implantable devices.

Follow-up of patients treated by cardiac resynchronization therapy (CRT) is of great interest to prevent health deterioration in the postoperative period. In this purpose, data recorded in implantable devices (ID) can be informative. They are large, multivariate, evolutive with time, and then difficult to interpret. This study proposes a methodology, based on Multiple Correspondence Analysis (MCA) and fuzzy coding, to i) reduce the dimensionality of these data, ii) characterize the factorial axes by the variables recorded in the ID, iii) identify evolutions of patients in the factorial plane which are related to health deterioration. The results show that the first three axes of the MCA contain more than 90% of the total variance and are linked to the functional state of the patients. A simple clustering of the patients is performed and defines an area of the factorial plane, correlated with a degradation of patients' clinical state.

[Ischemic mitral regurgitation: contributions of exercise echocardiography and new therapeutic perspectives]. / Insuffisance mitrale ischémique: apport de l'échocardiographie d'effort et nouvelles perspectives thérapeutiques.

The ischemic mitral regurgitation is defined by a left ventricular muscle disease affecting the function of normal mitral valve leaflets. This kind of mitral regurgitation is founded in about 20% of the ischemic cardiomyopathy and is attributed to the remodelling of the left ventricular shape. Its development is associated to a significantly worse prognosis. Frequently this ischemic mitral regurgitation will be associated to episode of acute heart failure decompensation. Its diagnosis is sometimes challenging as the degree of regurgitation might be extremely variable and affected by loading conditions. Echocardiography and especially exercise stress echocardiography has been demonstrated as an extremely powerful tool for its diagnosis and the prognostic evaluation. Its treatment should include the pharmacological treatment of the chonic heart failure and we are still waiting data in regard to the prognostic role of surgical mitral valvuloplastie. Works are still ongoing.