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Aims: One-third of dilated cardiomyopathy patients receiving a biventricular pacing-device do not respond to this form of therapy. Therefore, the utility of mechanical dyssynchrony by real-time 3D echocardiography (RT3DE) for predicting systolic response to biventricular pacing, of which maximal rate of pressure rise (dP/dt(max)) served as the gold-standard, was evaluated. Methods and Results: Seventeen consecutive heart failure patients (aged 64 +/- 10 years, 8 male, 6 ischaemic cardiomyopathy, mean QRS duration 136 +/- 32 ms) underwent RT3DE and biventricular pacing. Post-processing software provided data of global left ventricular (LV) function and the systolic dyssynchrony index of 17 LV segments (SDI(17), %) for mechanical dyssynchrony. During biventricular pacing, percentual change in dP/dt(max) compared to the non-pacing mode, DeltadP/dt(max) was measured invasively with conductance catheters. LV ejection fraction was 31 +/- 10%, SDI(17) was 10.2 +/- 4.2% and percentual DeltadP/dt(max) during biventricular pacing was 14.5 +/- 12.4. A significant correlation (r = 0.729, P = 0.001) was found between SDI(17) and percentual DeltadP/dt(max), and between QRS duration and percentual DeltadP/dt(max) (r = 0.721, P = 0.001). Conclusion: The present study suggests that mechanical dyssynchrony measured by RT3DE shows a good correlation with invasively determined acute haemodynamic response to biventricular pacing in patients with symptomatic dilated cardiomyopathy. Future studies are needed to further define the clinical utility of RT3DE in identifying patients who are most likely to respond to cardiac resynchronization therapy. [ABSTRACT FROM AUTHOR]

The right ventricular apex has been used for cardiac stimulation because this position is easily accessible and is associated with a stable position of the electrode with a low dislodgement rate. This position, however, is associated with a dyssynchronous left ventricular contraction with subsequent deleterious haemodynamic effects. Alternative stimulation sites have been studied extensively because of a potentially better haemodynamic effect compared with right ventricular apex pacing.Using a Cochrane search strategy, nine studies were selected to analyze the haemodynamic effects of right ventricular outflow-tract pacing. The results of these studies (n=217) were pooled and indicated a significantly better haemodynamic effect (odds ratio 0.34, confidence interval 0.15–0.53) compared with right ventricular apex pacing. Therefore, these data suggest that right ventricular outflow-tract pacing may offer a modest but significant benefit over right ventricular apex pacing in patients selected for pacemaker implantation on the basis of symptomatic bradyarrhythmias. [ABSTRACT FROM PUBLISHER]

Introduction Atrioventricular sequential pacing involves stimulation from electrodes in the right atrium, generally the atrial appendage (RAA) and the right ventricular apex. The appendage, however, may be unsuitable if a stable position cannot be achieved. The aim of this study was to assess the haemodynamic consequences of different atrial stimulation sites during DDD pacing. Methods In 12 consecutive patients (mean age 67±7 years) who underwent DDD pacemaker implantation, an additional temporary bipolar pacing electrode was positioned on the right atrial free wall. Pacing was performed alternating from the two locations at 85, 100 and 120 beats per minute (bpm). Paced atrioventricular delay was set at 180 ms. Cardiac output and mitral inflow measurements were performed using Doppler echocardiography. Results Pacing at 85 and 100 bpm resulted in a significantly higher A-peak velocity from the RAA compared with the right atrial free wall. Cardiac index was consistently higher from the RAA location (2·4±1·2 vs 2·1± 0·9 l. min−1m−2 at 85 bpm, 2·71±1·4 vs 2·35±1·1 l. min−1m−2 at 100 bpm and 2·94±1·5 vs 2·61±1·4 l. min−1m−2 at 120 bpm, P<0·05). Conclusion Stimulation from the RAA was superior to stimulation from the right atrial free wall with respect to left ventricular filling and cardiac output. Compared with stimulation from the right atrial free wall, RAA pacing resulted in an increase of 10–15% in cardiac output. [ABSTRACT FROM PUBLISHER]

A 74-year-old patient was referred for a rapidly increasing pacing threshold 9 months after DDD pacemaker implantation because of symptomatic total atrioventricular (AV) block. She had a history of hypertension, diabetes with micro-angiopathy and a recent transient ischaemic attack.The paced electrocardiogram on admission had a right bundle branch block pattern and 3-dimensional transoesophageal echocardiography demonstrated passage of the lead through an atrial septal defect with a left ventricular position in addition to moderate atherosclerosis of the ascending aorta. No thrombus could be detected on the lead. Percutaneous extraction is usually not recommended because of the risk of mobilization of thrombus material. However, the risk of stroke during removal using cardiopulmonary bypass in this patient was considerably increased because of the presence of multiple independent risk factors. Therefore, percutaneous extraction using a locking device was selected and performed without complications: follow-up was uneventful. [ABSTRACT FROM PUBLISHER]

In a patient admitted with symptomatic complete heart block, a DDD pacemaker was implanted. Prior to implantation, echocardiography showed normal left ventricular function. Shortly after implantation, acute congestive heart failure developed with extensive regional hypo- and akinetic segments in the anteroseptal, anterolateral and apical region. Subsequent perfusion imaging with methoxyiso-buticeisonitrite (MIBI) at rest demonstrated hypoperfusion in the same regions while coronary angiography showed normal epicardial coronary vessels. Thus, impaired regional coronary flow can be associated with cardiac stimulation, inducing marked deterioration of left ventricular function. [ABSTRACT FROM PUBLISHER]

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty (PTCA) for first AMI, and intravenous MCE was determined before, and at 1 and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE 1 hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p <0.001) and was in an analysis of variance the best parameter to predict GWMI 4 weeks after AMI. The ST-segment elevation index was close in its predictive value. Considering only invasive parameters of reperfusion myocardial blush grade was the best predictor of GWMI at 4 weeks (R(2) = 0.3107, p <0.001). A MCE perfusion defect size at 24 hours of > or =50% of the MCE perfusion defect size before PTCA was used to define myocardial nonreperfusion. In a multivariate analysis, low myocardial blush grade class was the best predictor of nonreperfusion defined by MCE. Thus, intravenous MCE allows better prediction of left ventricular function 4 weeks after AMI than other evaluated parameters of myocardial reperfusion. Myocardial blush grade is the best predictor of nonreperfusion defined by MCE and is the invasive parameter with the greatest predictive value for left ventricular function after AMI. Coronary flow parameters are less predictive. [ABSTRACT FROM AUTHOR]

Ultra-wideband (UWB) indoor positioning systems have the potential to achieve sub-decimeter-level accuracy. However, the ranging performance degrades significantly under non-line-of-sight (NLoS) conditions. The detection and mitigation of NLoS conditions is a complex problem and has been the subject of many works over the past decades. When localizing pedestrians, human body shadowing (HBS) is a particular and specific cause of NLoS. In this paper, we present an HBS mitigation strategy based on the orientation of the body and tag relative to the UWB anchors. Our HBS mitigation strategy involves a robust range error model that interacts with a tracking algorithm. The model consists of a bank of Gaussian Mixture Models (GMMs), from which an appropriate GMM is selected based on the relative body-tag-anchor orientation. The relative orientation is estimated by means of an inertial measurement unit (IMU) attached to the tag and a candidate position provided by the tracking algorithm. The selected GMM is used as a likelihood function for the tracking algorithm to improve localization accuracy. Our proposed approach was realized for two tracking algorithms. We validated the implemented algorithms on dynamic UWB ranging measurements, which were performed in an industrial lab environment. The proposed algorithms outperform other state-of-the-art algorithms, achieving a 37% reduction of the p75 error.

Continuing medical education (CME) plays a critical role in healthcare, helping to ensure patients receive the best possible care and optimal disease management. Considering the obstacles to engaging in CME activities faced by the clinical community, as well as employing learning theory, Liberum IME developed Classroom to Clinic™ - a bespoke, accredited learning format that can be tailored to individuals' educational needs and time constraints. Through monitoring use, and incorporating qualitative and quantitative feedback, we continuously evaluate the usability, value and accessibility of this programme and adapt subsequent iterations accordingly. An example of this is the way we adapted our engagement of facilitators. Originally this was accomplished by targeting individuals for train-the-trainer events, but it was clear this was more effective in some countries than in others. To address this variability, we piloted launching a new module at a relevant large international congress. This aimed to instigate a cascade in education sharing, from congress attendees to peers at their clinics and across departments and hospitals. So far, the programme has reported encouraging improvements in uptake, as well as knowledge, competence and clinical practice, while qualitative feedback has allowed for the identification of further educational needs and continued evolution of the programme., Competing Interests: No potential conflict of interest was reported by the authors., (© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Mangroves are unique coastal ecosystems, located in tropical and subtropical regions. Yet, the functioning of these essential ecosystems is threatened by the presence of pollutants, including pesticides originating from agricultural activities. We investigated pesticide residues in the Guayas estuarine environment, since agricultural activities rapidly increased in the Guayas river basin over the past decades. A multi-residue analysis involving a selection of 88 pesticides was performed on the white meat and the hepatopancreas of the red mangrove crab (Ucides Occidentalis) at 15 sampling sites within the Guayas estuary along with water, sediment, and leaves samples. We found that 35 active compounds were present in the Guayas estuary, of which pyrimethanil was most commonly detected and had the highest concentrations in almost all compartments. Also, cadusafos was present in all studied compartments of the Guayas mangrove system and several prohibited pesticides (including carbendazim, carbofuran, and parathion) were detected. An ecotoxicological and probabilistic consumer risk assessment pointed out that current butachlor, carbendazim, and fludioxonil concentrations can cause adverse effects in aquatic organisms in the long term. Moreover, high potential acute and chronic risks of cadusafos residues on aquatic invertebrates and of diuron on algae in the Guayas wetlands were observed. Still, the exposure results indicated that the health risk for the consumers of the commercial red mangrove crab is low concerning cadusafos, chlorpyrifos, diuron, linuron, and pyrimethanil residues in crab tissues. The findings presented in this research can provide a useful basis for local water managers and environmental conservation groups to act and reduce the usage of pesticides, to avoid threatening aquatic and human health., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

We present a smartphone-based indoor localisation system, able to track pedestrians over multiple floors. The system uses Pedestrian Dead Reckoning (PDR), which exploits data from the smartphone's inertial measurement unit to estimate the trajectory. The PDR output is matched to a scaled floor plan and fused with model-based WiFi received signal strength fingerprinting by a Backtracking Particle Filter (BPF). We proposed a new Viterbi-based floor detection algorithm, which fuses data from the smartphone's accelerometer, barometer and WiFi RSS measurements to detect stairs and elevator usage and to estimate the correct floor number. We also proposed a clustering algorithm on top of the BPF to solve multimodality, a known problem with particle filters. The proposed system relies on only a few pre-existing access points, whereas most systems assume or require the presence of a dedicated localisation infrastructure. In most public buildings and offices, access points are often available at smaller densities than used for localisation. Our system was extensively tested in a real office environment with seven 41 m × 27 m floors, each of which had two WiFi access points. Our system was evaluated in real-time and batch mode, since the system was able to correct past states. The clustering algorithm reduced the median position error by 17% in real-time and 13% in batch mode, while the floor detection algorithm achieved a 99.1% and 99.7% floor number accuracy in real-time and batch mode, respectively.

Background: The high demand for health care services and the growing capability of artificial intelligence have led to the development of conversational agents designed to support a variety of health-related activities, including behavior change, treatment support, health monitoring, training, triage, and screening support. Automation of these tasks could free clinicians to focus on more complex work and increase the accessibility to health care services for the public. An overarching assessment of the acceptability, usability, and effectiveness of these agents in health care is needed to collate the evidence so that future development can target areas for improvement and potential for sustainable adoption., Objective: This systematic review aims to assess the effectiveness and usability of conversational agents in health care and identify the elements that users like and dislike to inform future research and development of these agents., Methods: PubMed, Medline (Ovid), EMBASE (Excerpta Medica dataBASE), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Web of Science, and the Association for Computing Machinery Digital Library were systematically searched for articles published since 2008 that evaluated unconstrained natural language processing conversational agents used in health care. EndNote (version X9, Clarivate Analytics) reference management software was used for initial screening, and full-text screening was conducted by 1 reviewer. Data were extracted, and the risk of bias was assessed by one reviewer and validated by another., Results: A total of 31 studies were selected and included a variety of conversational agents, including 14 chatbots (2 of which were voice chatbots), 6 embodied conversational agents (3 of which were interactive voice response calls, virtual patients, and speech recognition screening systems), 1 contextual question-answering agent, and 1 voice recognition triage system. Overall, the evidence reported was mostly positive or mixed. Usability and satisfaction performed well (27/30 and 26/31), and positive or mixed effectiveness was found in three-quarters of the studies (23/30). However, there were several limitations of the agents highlighted in specific qualitative feedback., Conclusions: The studies generally reported positive or mixed evidence for the effectiveness, usability, and satisfactoriness of the conversational agents investigated, but qualitative user perceptions were more mixed. The quality of many of the studies was limited, and improved study design and reporting are necessary to more accurately evaluate the usefulness of the agents in health care and identify key areas for improvement. Further research should also analyze the cost-effectiveness, privacy, and security of the agents., International Registered Report Identifier (irrid): RR2-10.2196/16934., (©Madison Milne-Ives, Caroline de Cock, Ernest Lim, Melissa Harper Shehadeh, Nick de Pennington, Guy Mole, Eduardo Normando, Edward Meinert. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 22.10.2020.)

Background: Vaccination is a critical step in reducing child mortality; however, vaccination rates have declined in many countries in recent years. This decrease has been associated with an increase in the outbreak of vaccine-preventable diseases. The potential for leveraging mobile platforms to promote vaccination coverage has been investigated in the development of numerous mobile apps. Although many are available for public use, there is little robust evaluation of these apps., Objective: This systematic review aimed to assess the effectiveness of apps supporting childhood vaccinations in improving vaccination uptake, knowledge, and decision making as well as the usability and user perceptions of these apps., Methods: PubMed, Excerpta Medica Database (EMBASE), Web of Science, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Education Resources Information Center (ERIC) databases were systematically searched for studies published between 2008 and 2019 that evaluated childhood vaccination apps. Two authors screened and selected studies according to the inclusion and exclusion criteria. Data were extracted and analyzed, and the studies were assessed for risk of bias., Results: A total of 28 studies evaluating 25 apps met the inclusion criteria and were included in this analysis. Overall, 9 studies assessed vaccination uptake, of which 4 reported significant benefits (P<.001 or P=.03) of the implementation of the app. Similarly, 4 studies indicated a significant (P≤.054) impact on knowledge and on vaccination decision making. Patient perceptions, usability, and acceptability were generally positive. The quality of the included studies was found to be moderate to poor, with many aspects of the methodology being unclear., Conclusions: There is little evidence to support the use of childhood vaccination apps to improve vaccination uptake, knowledge, or decision making. Further research is required to understand the dichotomous effects of vaccination-related information provision and the evaluation of these apps in larger, more robust studies. The methodology of studies must be reported more comprehensively to accurately assess the effectiveness of childhood vaccination apps and the risk of bias of studies., International Registered Report Identifier (irrid): RR2-10.2196/16929., (©Caroline de Cock, Michelle van Velthoven, Madison Milne-Ives, Mary Mooney, Edward Meinert. Originally published in JMIR mHealth and uHealth (http://mhealth.jmir.org), 18.05.2020.)

Background: With a growing focus on patient interaction with health management, mobile apps are increasingly used to deliver behavioral health interventions. The large variation in these mobile health apps-their target patient group, health behavior, and behavioral change strategies-has resulted in a large but incohesive body of literature., Objective: This systematic review aimed to assess the effectiveness of mobile apps in improving health behaviors and outcomes and to examine the inclusion and effectiveness of behavior change techniques (BCTs) in mobile health apps., Methods: PubMed, EMBASE, CINAHL, and Web of Science were systematically searched for articles published between 2014 and 2019 that evaluated mobile apps for health behavior change. Two authors independently screened and selected studies according to the eligibility criteria. Data were extracted and the risk of bias was assessed by one reviewer and validated by a second reviewer., Results: A total of 52 randomized controlled trials met the inclusion criteria and were included in the analysis-37 studies focused on physical activity, diet, or a combination of both, 11 on drug and alcohol use, and 4 on mental health. Participant perceptions were generally positive-only one app was rated as less helpful and satisfactory than the control-and the studies that measured engagement and usability found relatively high study completion rates (mean 83%; n=18, N=39) and ease-of-use ratings (3 significantly better than control, 9/15 rated >70%). However, there was little evidence of changed behavior or health outcomes., Conclusions: There was no strong evidence in support of the effectiveness of mobile apps in improving health behaviors or outcomes because few studies found significant differences between the app and control groups. Further research is needed to identify the BCTs that are most effective at promoting behavior change. Improved reporting is necessary to accurately evaluate the mobile health app effectiveness and risk of bias., (©Madison Milne-Ives, Ching Lam, Caroline De Cock, Michelle Helena Van Velthoven, Edward Meinert. Originally published in JMIR mHealth and uHealth (http://mhealth.jmir.org), 18.03.2020.)

Background: Conversational agents (also known as chatbots) have evolved in recent decades to become multimodal, multifunctional platforms with potential to automate a diverse range of health-related activities supporting the general public, patients, and physicians. Multiple studies have reported the development of these agents, and recent systematic reviews have described the scope of use of conversational agents in health care. However, there is scarce research on the effectiveness of these systems; thus, their viability and applicability are unclear., Objective: The objective of this systematic review is to assess the effectiveness of conversational agents in health care and to identify limitations, adverse events, and areas for future investigation of these agents., Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols will be used to structure this protocol. The focus of the systematic review is guided by a population, intervention, comparator, and outcome framework. A systematic search of the PubMed (Medline), EMBASE, CINAHL, and Web of Science databases will be conducted. Two authors will independently screen the titles and abstracts of the identified references and select studies according to the eligibility criteria. Any discrepancies will then be discussed and resolved. Two reviewers will independently extract and validate data from the included studies into a standardized form and conduct quality appraisal., Results: As of January 2020, we have begun a preliminary literature search and piloting of the study selection process., Conclusions: This systematic review aims to clarify the effectiveness, limitations, and future applications of conversational agents in health care. Our findings may be useful to inform the future development of conversational agents and promote the personalization of patient care., International Registered Report Identifier (irrid): PRR1-10.2196/16934., (©Caroline de Cock, Madison Milne-Ives, Michelle Helena van Velthoven, Abrar Alturkistani, Ching Lam, Edward Meinert. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 09.03.2020.)

Background: The decline in the uptake of routine childhood vaccinations has resulted in outbreaks of vaccine-preventable diseases. Vaccination apps can be used as a tool to promote immunization through the provision of reminders, dissemination of information, peer support, and feedback., Objective: The aim of this review is to systematically review the evidence on the use of apps to support childhood vaccination uptake, information storage, and record sharing., Methods: We will identify relevant papers by searching the following electronic databases: PubMed, Embase by Ovid, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and Education Resources Information Center (ERIC). We will review the reference lists of those studies that we include to identify relevant additional papers not initially identified using our search strategy. In addition to the use of electronic databases, we will search for grey literature on the topic. The search strategy will include only terms relating to or describing the intervention, which is app use. As almost all titles and abstracts are in English, 100% of these will be reviewed, but retrieval will be confined to papers written in the English language. We will record the search outcome on a specifically designed record sheet. Two reviewers will select observational and intervention studies, appraise the quality of the studies, and extract the relevant data. All studies will involve the use of apps relating to child vaccinations. The primary outcome is the uptake of vaccinations. Secondary outcomes are as follows: (1) use of app for sharing of information and providing vaccination reminders and (2) use of app for storage of vaccination information; knowledge and decision making by parents regarding vaccination (ie, risks and benefits of vaccination); costs and cost-effectiveness of vaccination apps; use of the app and measures of usability (eg, usefulness, acceptability, and experiences of different users: parents and health care professionals); use of technical standards for development of the app; and adverse events (eg, data leaks and misinformation). We will exclude studies that do not study an app. We anticipate a limited scope for meta-analysis and will provide a narrative overview of findings and tabular summaries of extracted data., Results: This project was funded by the Sir David Cooksey Fellowship in Healthcare Translation at the University of Oxford, Oxford, United Kingdom. We will submit the full systematic review for publication in the Journal of Medical Internet Research., Conclusions: This review will follow, where possible, the Cochrane Collaboration and the Centre for Review and Dissemination methodologies for conducting systematic reviews. We will report our findings based on guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The review results will be used to inform the development of a vaccination app., International Registered Report Identifier (irrid): PRR1-10.2196/16929., (©Michelle Helena Van Velthoven, Madison Milne-Ives, Caroline de Cock, Mary Mooney, Edward Meinert. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 05.02.2020.)

Comprehensive pharmacogenomic understanding requires both robust genomic and demographic data. Patient registries present an opportunity to collect large amounts of robust, patient-level data. Pharmacogenomic advancement in the treatment of infectious diseases is yet to be fully realised. Herpes simplex virus (HSV) is one disease for which pharmacogenomic understanding is wanting. This paper aims to understand the key factors that impact data collection quality for medical registries and suggest potential design features of an HSV medical registry to overcome current constraints and allow for this data to be used as a complement to genomic and clinical data to further the treatment of HSV. This paper outlines the discovery phase for the development of an HSV registry with the aim of learning about the users and their contexts, the technological constraints and the potential improvements that can be made. The design requirements and user stories for the HSV registry have been identified for further alpha phase development. The current landscape of HSV research and patient registry development were discussed. Through the analysis of the current state of the art and thematic user analysis, potential design features were elucidated to facilitate the collection of high-quality, robust patient-level data which could contribute to advances in pharmacogenomic understanding and personalised medicine in HSV. The user requirements specification for the development of an HSV registry has been summarised and implementation strategies for the alpha phase discussed.

Background: Haloperidol is the most frequently prescribed antipsychotic for delirium symptoms. The risk of QTc prolongation often raises concerns, although the effect of haloperidol on QTc interval has not yet been investigated in a randomised placebo-controlled fixed-dose study., Methods: A subanalysis of a randomised double-blind placebo-controlled study was conducted to evaluate the effect of prophylactic haloperidol 1 mg or placebo 1 mg orally twice-daily (maximum of 14 doses) on QTc interval in patients aged 70 years and over. Bedside, 12-lead ECGs were recorded before, during and after the one-week intervention period. Automatic QTc measurements were obtained in addition to manual measurements of QT and RR intervals, blinded for treatment status. Manual measurements were corrected (QTc) using Bazett (QTc-B), Framingham (QTc-Fa), Fridericia (QTc-Fi) and Hodges (QTc-H) methods. Mixed model analyses were used to test for differences in longitudinal course of QTc between patients receiving haloperidol and placebo., Results: ECG recordings of 72 patients (haloperidol n = 38) were analysed, 45.8% male. Median (range) haloperidol serum concentration on day 4 was 0.71 (0.32-1.82) µg/L ( n = 23). Longitudinal course of mean QTc did not significantly differ between treatment arms for any of the automatic or manually derived QTc values., Conclusions: Low dose oral haloperidol did not result in QTc prolongation in older acutely hospitalised patients. Results may not be generalizable to patients with existing ECG abnormalities such as atrial fibrillation.

Objective: The objective of the study was to compare estimates of pediatric cumulative exposure and lifetime attributable risk (LAR) of radiation-induced cancer from dental radiology between cleft palate (CP) subjects and age- and gender-matched controls (non-CP), with and without orthodontic treatment., Materials and Methods: The radiation exposure frequency of CP subjects and non-CP controls with and without orthodontic treatment was compared for two-dimensional radiography (intra-oral, panoramic and cephalometric radiography), computed tomography (CT), and cone-beam CT (CBCT) using cumulative radiation dose as an estimate. From this dose estimate, the age- and gender-dependent risk for radiation-induced stochastic effects was calculated for each patient group., Results: CP patients received more radiographic examinations than non-CP controls, with the exception of intra-oral radiographs. The cumulative dose to CP patients was considerably higher (1963 μSv at the age of 20 years) than non-CP patients with (597 μSv) and without (383 μSv) orthodontic treatment, primarily due to the higher frequency of CT scanning. Accordingly, CP patients had a three to five times higher LAR than non-CP patients., Conclusions: This study suggests a significantly higher lifetime radiation exposure to CP patients than non-CP controls from dental radiographic procedures. Diagnostic benefits from the use of CT and CBCT in children must be justified and appropriate dose optimization strategies implemented., Clinical Relevance: The present study indicates the need for proper justification and optimization of pediatric exposures in dentistry, with a special focus on high-risk groups.

Aims: This study evaluates the relative importance of two components of QRS prolongation, myocardial conduction velocity and travel distance of the electrical wave front (i.e. path length), for the prediction of acute response to cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB) patients., Methods and Results: Thirty-two CRT candidates (ejection fraction <35%, LBBB) underwent cardiac magnetic resonance (CMR) imaging to provide detailed information on left ventricular (LV) dimensions. Left ventricular end-diastolic volume (LVEDV) was used as a primary measure for path length, subsequently QRSd was normalized to LV dimension (i.e. QRSd divided by LVEDV) to adjust for conduction path length. Invasive pressure-volume loop analysis at baseline and during CRT was used to assess acute pump function improvement, expressed as LV stroke work (SW) change. During CRT, SW improved by +38 ± 46% (P < 0.001). The baseline LVEDV was positively related to QRSd (R = 0.36, P = 0.044). Despite this association, a paradoxical inverse relation was found between LVEDV and SW improvement during CRT (R = -0.40; P = 0.025). Baseline unadjusted QRSd was found to be unrelated to SW changes during CRT (R = 0.16; P = 0.383), whereas normalized QRSd (QRSd/LVEDV) yielded a strong correlation with CRT response (R = 0.49; P = 0.005). Other measures of LV dimension, including LV length, LV diameter, and LV end-systolic volume, showed similar relations with normalized QRSd and SW improvement., Conclusion: Since normalized QRSd reflects myocardial conduction properties, these findings suggest that myocardial conduction velocity rather than increased path length mainly determines response to CRT. Normalizing QRSd to LV dimension might provide a relatively simple method to improve patient selection for CRT., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Background: The contribution of right ventricular (RV) stimulation to cardiac resynchronisation therapy (CRT) remains controversial. RV stimulation might be associated with adverse haemodynamic effects, dependent on intrinsic right bundle branch conduction, presence of scar, RV function and other factors which may partly explain non-response to CRT. This study investigates to what degree RV stimulation modulates response to biventricular (BiV) stimulation in CRT candidates and which baseline factors, assessed by cardiac magnetic resonance imaging, determine this modulation., Methods and Results: Forty-one patients (24 (59 %) males, 67 ± 10 years, QRS 153 ± 22 ms, 21 (51 %) ischaemic cardiomyopathy, left ventricular (LV) ejection fraction 25 ± 7 %), who successfully underwent temporary stimulation with pacing leads in the RV apex (RVapex) and left ventricular posterolateral (PL) wall were included. Stroke work, assessed by a conductance catheter, was used to assess acute haemodynamic response during baseline conditions and RVapex, PL (LV) and PL+RVapex (BiV) stimulation. Compared with baseline, stroke work improved similarly during LV and BiV stimulation (∆+ 51 ± 42 % and ∆+ 48 ± 47 %, both p < 0.001), but individual response showed substantial differences between LV and BiV stimulation. Multivariate analysis revealed that RV ejection fraction (β = 1.01, p = 0.02) was an independent predictor for stroke work response during LV stimulation, but not for BiV stimulation. Other parameters, including atrioventricular delay and scar presence and localisation, did not predict stroke work response in CRT., Conclusion: The haemodynamic effect of addition of RVapex stimulation to LV stimulation differs widely among patients receiving CRT. Poor RV function is associated with poor response to LV but not BiV stimulation.

Visual quantification of interictal epileptiform activity is time consuming and requires a high level of expert's vigilance. This is especially true for overnight recordings of patient suffering from epileptic encephalopathy with continuous spike and waves during slow-wave sleep (CSWS) as they can show tens of thousands of spikes. Automatic spike detection would be attractive for this condition, but available algorithms have methodological limitations related to variation in spike morphology both between patients and within a single recording. We propose a fully automated method of interictal spike detection that adapts to interpatient and intrapatient variation in spike morphology. The algorithm works in five steps. (1) Spikes are detected using parameters suitable for highly sensitive detection. (2) Detected spikes are separated into clusters. (3) The number of clusters is automatically adjusted. (4) Centroids are used as templates for more specific spike detections, therefore adapting to the types of spike morphology. (5) Detected spikes are summed. The algorithm was evaluated on EEG samples from 20 children suffering from epilepsy with CSWS. When compared to the manual scoring of 3 EEG experts (3 records), the algorithm demonstrated similar performance since sensitivity and selectivity were 0.3% higher and 0.4% lower, respectively. The algorithm showed little difference compared to the manual scoring of another expert for the spike-and-wave index evaluation in 17 additional records (the mean absolute difference was 3.8%). This algorithm is therefore efficient for the count of interictal spikes and determination of a spike-and-wave index., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Cardiac resynchronization therapy (CRT) is characterized by a approximately 30% non-response. Invasive haemodynamic measurements are a traditional method to evaluate response to CRT. This study evaluates the correlation between acute changes in dP/dt(max) and Stroke Work (SW) during CRT., Methods: Thirty-four CRT candidates were haemodynamically evaluated by pressure-volume loop analysis during biventricular pacing., Results: Mean dP/dt(max) and SW at baseline were 854 +/- 198 and 5186 +/- 2349, and displayed an increase during pacing of 106 +/- 117 mmHg/s (13% +/- 14%) and 1303 +/- 3039 mL/mmHg (30% +/- 52%), respectively. No correlation was found between the percentage change in dP/dt(max) and SW (R = 0.06, P = ns). When defining response an augmentation of 10% relative to baseline for both parameters, 16 patients demonstrated an ambiguous response., Conclusion: Although both parameters display an average increase during pacing, the change relative to baseline values of SW and dP/dt(max) is not related.

Objective: The WHO recommends a daily Ca intake for postmenopausal women of 1300 mg. The objective of the present study was to assess the dietary Ca intake in European postmenopausal osteoporotic women., Design, Setting and Subjects: Assessment of dietary Ca intake (food and supplements) was performed with a validated self-questionnaire in 8524 osteoporotic women from nine European countries (Belgium, Denmark, France, Germany, Hungary, Italy, Poland, Spain and the UK)., Results: Mean age of the patients was 74.2 (sd 7.1) years, mean BMI was 25.7 (sd 4.2) kg/m2. Of the study population, 37.2 % of the women took Ca supplements. The mean dietary intake of Ca was 930.7 (sd 422.9) mg/d. The lowest Ca intake was found in Hungary (586.7 (sd 319.1) mg/d) and the highest in Denmark (1145.6 (sd 463.0) mg/d). In the whole study population, only 19.1 % of the women had a dietary Ca intake >1300 mg/d. Only 17.1 % of women aged over 75 years achieved 1300 mg/d compared with 20.5 % of women aged less than 75 years (P = 0.0001 for the difference between the two groups)., Conclusion: Dietary intake of Ca is very low in European postmenopausal women. A greater awareness is needed to resolve this public health problem.

Fifty years after its introduction, cardiac pacing has evolved from an experimental medical treatment to an expanding field in today's cardiology. Only recently there is accumulating evidence that prolonged stimulation of the right ventricular apex is associated with clinically significant adverse effects. In this commentary, the potential adverse effects are summarised and potential modifications in contemporary pacing are discussed. (Neth Heart J 2008;16(Suppl1):S12-S14.).

Objective: Studies have shown that low serum vitamin D levels are associated with secondary hyperparathyroidism, which decreases bone strength and increases fracture risk, most notably after 50 years of age. The objective of this study was to evaluate the vitamin D status of postmenopausal women in France., Methods: We conducted a cross-sectional observational study of 1292 menopausal women with osteoporosis or osteopenia. The age range was 52-94 years. Serum 25-OH-vitamin D was assayed in each patient. Based on data in the literature, we used four 25-OH-D cutoffs to define vitamin D deficiency: 30, 50, 75, and 80 nmol/L (<12, <20, <30, and <32 ng/ml)., Results: Mean serum 25-OH-D was 51.5+/-26.1 nmol/L (about 20.6+/-10.4 ng/ml). In the 343 (26.5%) patients taking supplemental vitamin D with or without supplemental calcium, the mean serum 25-OH-D level was significantly higher than in the other patients (65.0+/-26.0 ng/ml vs. 46.6+/-18.6 ng/ml; P<0.001). In the subgroup not taking vitamin D supplements, the prevalence of vitamin D deficiency was 27.3%, 54.1%, 89.9%, and 93.2% with the 30, 50, 75, and 80 nmol/L cutoffs, respectively. The mean 25-OH-D level varied across seasons (P<0.001), with the highest value being obtained in summer (53.4+/-18.7 nmol/L; about 21.3+/-7.5 ng/ml)., Conclusion: Vitamin D deficiency is common among postmenopausal women with osteoporosis or osteopenia in France.

Seizures starting in patients over 60 years old are frequent. Diagnosis is sometimes difficult and frequently under- or overrated. Cerebrovascular disorders are the main cause of a first seizure. Because of more frequent comorbidities, physiologic changes, and a higher sensitivity to drugs, treatment has some specificity in elderly people. The aim of this paper is to present the result of a consensus meeting held in October 2004 by a Belgian French-speaking group of epileptologists and to propose guidelines for the management and the treatment of epilepsy in elderly people.

Report of two patients with severe loss of visual acuity after surgery in the head and neck area. Ophthalmic examination and imaging studies demonstrate an occlusion of the ophthalmic and central retinal arteries. In both cases, the underlying physiopathology is the embolisation by an intra-operatively injected substance. Embolisation is thought to occur via anastomosing branches between the external and internal carotid arteries. These cases demonstrate that surgery in head and neck area can result in unexpected and devastating ocular complications.

A system for analyzing left ventricular (LV) electromechanical asynchrony based on transesophageal 3-dimensional echocardiography (3-DE) and semi-automatic endocardial contour detection is described. Eighteen consecutive patients underwent 3-DE. Using TomTec 4DLV software, a 3-dimensional endocardial surface was reconstructed throughout the cardiac cycle. Matlab software generated color-coded polar maps, displaying regional LV displacement and its timing. At the segmental level, Bland-Altmann assessment showed intraobserver variability of LV displacement of 0.1 +/- 3.0 mm and timing of -5.6 +/- 160 ms (bias +/- 2 SD) for all segments and -1.6 +/- 94 ms for the nonapical segments. The combination of 3-DE and semi-automatic contour detection is feasible and provides unique information for assessing regional LV endocardial displacement and electromechanical asynchrony.

Dissection of the coronary sinus during lead implantation for biventricular pacemaker implantation in patients with advanced heart failure is a serious complication that has occasionally been reported. We report on the clinical outcome and angiographic follow-up in a series of 7 patients with acute major dissection from 103 consecutive attempts (incidence 6.8%). Serial echocardiography was performed in all patients and all underwent follow-up angiography 2-3 months after the procedure. In 1 patient, pericardial extravasation was seen during retrograde venography. Clinical follow-up was uneventful except for one other patient who complained of prolonged chest discomfort for several hours after the procedure. In none of the patients were there signs of pericardial effusion or tamponade demonstrated on echocardiography. Venograms during the procedure and after follow-up were analysed using a quantitative coronary angiography system (CAAS II). Parameters included minimal luminal diameter, diameter stenosis, minimal cross-sectional area and an estimation of the reference diameter. There were no significant differences in all analysed parameters, although in 1 patient a small partial dissection was present. Thus, although dissection of the coronary sinus following lead implantation for biventricular stimulation is not an uncommon complication, it is usually well tolerated. Long-term angiographic follow-up demonstrated no significant vessel damage or vessel remodeling.

Today, new pacing algorithms and stimulation methods for the prevention and interruption of atrial tachyarrhythmias can be applied on patients who need bradycardia pacing for conventional reasons. In addition, biventricular pacing as additive treatment for patients with severe congestive heart failure due to ventricular systolic dysfunction and prolonged intraventricular conduction has shown to improve symptoms and reduce hospital admissions. These new pacing technologies and the optimising of the pacing programmes are complex, expensive and time-consuming. Based on many clinical studies the indications for these devices are beginning to emerge. To support the cardiologist's decision-making and to prevent waste of effort and resources, the 'ad hoc committee' has provided preliminary recommendations for implantable devices to treat atrial tachyarrhythmias and to extend the treatment of congestive heart failure respectively.

The right ventricular apex has been used for cardiac stimulation because this position is easily accessible and is associated with a stable position of the electrode with a low dislodgement rate. This position, however, is associated with a dyssynchronous left ventricular contraction with subsequent deleterious haemodynamic effects. Alternative stimulation sites have been studied extensively because of a potentially better haemodynamic effect compared with right ventricular apex pacing. Using a Cochrane search strategy, nine studies were selected to analyze the haemodynamic effects of right ventricular outflow-tract pacing. The results of these studies (n=217) were pooled and indicated a significantly better haemodynamic effect (odds ratio 0.34, confidence interval 0.15-0.53) compared with right ventricular apex pacing. Therefore, these data suggest that right ventricular outflow-tract pacing may offer a modest but significant benefit over right ventricular apex pacing in patients selected for pacemaker implantation on the basis of symptomatic bradyarrhythmias.

Transvenous temporary pacing is associated with a substantial dislocation rate reported to range from 10 to 37%. The aim of the study was to assess the safety and utility of a recently introduced 3.5 Fr temporary pacing lead using active fixation in a consecutive series of 36 patients with prolonged (> or = 48 hours) transvenous temporary pacing (validation group). A group of 36 patients with prolonged transvenous pacing managed with a passive-fixation lead just prior to the introduction of the active-fixation lead served as a control group (reference group). Pacing related adverse events included dislocation, inappropriate pacing (i.e., two-fold or greater increase of initial pacing threshold), local infection, and thrombosis. There were no significant differences in patient characteristics or duration of pacing (5.84 +/- 2.4 days in the reference group vs 5.94 +/- 2.6 days in the validation group). Acute pacing threshold was significantly higher in the validation group as compared to the reference group (1.38 +/- 0.67 V vs. 0.7 +/- 0.21 V, P < 0.01). The dislocation rate was significantly lower in the validation group as compared to the reference group (5.5 vs 33.3%, P < 0.001). There were 11 (31%) pacing related adverse events in the validation group versus 21 (58%) in the reference group (P < 0.01). The vast majority of patients in the validation group (75%) had ambulatory temporary pacing. Thus, transvenous temporary pacing using active fixation is safe and is associated with a low dislocation rate and a reduction in pacing related adverse events.

A 74-year-old patient was referred for a rapidly increasing pacing threshold 9 months after DDD pacemaker implantation because of symptomatic total atrioventricular (AV) block. She had a history of hypertension, diabetes with micro-angiopathy and a recent transient ischaemic attack. The paced electrocardiogram on admission had a right bundle branch block pattern and 3-dimensional transoesophageal echocardiography demonstrated passage of the lead through an atrial septal defect with a left ventricular position in addition to moderate atherosclerosis of the ascending aorta. No thrombus could be detected on the lead. Percutaneous extraction is usually not recommended because of the risk of mobilization of thrombus material. However, the risk of stroke during removal using cardiopulmonary bypass in this patient was considerably increased because of the presence of multiple independent risk factors. Therefore, percutaneous extraction using a locking device was selected and performed without complications: follow-up was uneventful., (Copyright 2003 The European Society of Cardiology. Published by Elsevier Science Ltd.)

Background: Little is known about the differences between the corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and the 'frame count velocity' (FCV), an estimate of blood flow velocity derived from the TFC and the length of the related vessel, in each of the three epicardial coronary arteries., Methods: After angioplasty of 119 coronary vessels, 50 left anterior descending (LAD), 27 left circumflex (LCX) and 42 right coronary arteries (RCA), the CTFC was compared with the FCV assessed by measuring the length of the coronary arteries with an intracoronary guidewire., Results: The three vessels show a significant difference in mean length (the LAD was 14.5±1.6 cm, LCX 12.8±1.9 cm and RCA 11.3±1.4 cm, p<0.001 for all comparisons), making it possible to convert the TFC to the FCV with reasonable accuracy without having to use a guidewire. The mean length of the LCX and the RCA was found to be considerably longer than in previous reports on which the CTFC is based. In addition, with this method the estimation of the coronary blood flow velocity in the RCA is significantly higher compared with the LAD and LCX (23.0±7.9 cm/sec versus 17.6±7.4 cm/sec and 16.4±6.3 cm/sec, respectively, p<0.001)., Conclusion: With the TFC and the average length of the related coronary artery presented in this study, the FCV can be calculated for each of the three vessels resulting in a simple and, compared with the CTFC, more accurate angiographic estimation of the coronary blood flow velocity.

During single lead VDD pacing, loss of atrial sensing is reported to be 2%-11% of patients in the literature. The impact on quality-of-life and exercise duration has never been established. This study tried to assess the clinical relevance of loss of atrial sensing in patients with single lead VDD pacemakers. Twenty-one patients with total AV block were studied 3 months after single lead VDD pacemaker implantation. During a 6-minute walk test, atrial undersensing was verified and adjusted to achieve undersensing in < 5% (group 1), 5%-10% (group 2), and > 10% (group 3). Patients were allocated to each group in a randomized double blind crossover design. At the end of each 2-month study period all patients underwent symptom limited treadmill exercise testing. Subjective assessment of exercise difficulty was made using the Borg score, and quality-of-life assessment was performed using the Health Status Questionnaire. Exercise duration significantly decreased in group 3 (228 +/- 50 s) as compared to group 1 (257 +/- 42 s) and group 2 (250 +/- 46 sec) with an increase in the Borg score. Quality-of-life was decreased for three subscales in group 3 as compared to group 1 and group 2. In conclusion, atrial undersensing of > 10% in patients with single lead VDD pacing was associated with a decrease in exercise duration and increase in the subjective severity score, in addition to a decrease in quality-of-life. Atrial undersensing of < 10% did not effect exercise test results or quality-of-life. Since all studies reported intact atrioventricular synchrony in > or = 90% of patients, loss of atrial sensing is of limited clinical importance in these patients.

Single lead physiological pacing with right ventricular apex stimulation is feasible in patients with normal sinus node function and is associated with lower costs and a reduced complication rate. Left ventricular or biventricular pacing using the tributaries of the coronary sinus was reported to improve functional status and quality-of-life in patients with advanced congestive heart failure and intraventricular conduction delays. In addition, the proximal part of the coronary sinus has been successfully used for left atrial stimulation. The feasibility and pacing characteristics of left atrial- and left ventricular-based temporary pacing using a conventional single pass lead were studied. The tip of the lead was advanced in a distal position of the lateral or posterolateral branches of the coronary sinus, providing a stable position of the middle and proximal electrode pair in the first 2-7 cm of the coronary sinus. A successful stable position was achieved in 13 of 21 consecutive attempts. Using overlapping biphasic (OLBI) stimulation, left atrial and left ventricular pacing threshold were 2.3 +/- 0.6 and 2.5 +/- 0.5 V, respectively. Acceptable sensing values were measured for P waves (4.1 +/- 0.7 mV) and R waves (9.7 +/- 3.9 mV). There was a good correlation between the diameter of the coronary sinus as assessed by quantitative coronary angiography at the level of the middle and proximal rings and atrial pacing threshold (r = 0.92, P < 0.0001). Thus, single lead left atrial- and left ventricular-based pacing is feasible although further development is necessary to increase the success rate for stable stimulation at both sites.

Introduction: Atrioventricular sequential pacing involves stimulation from electrodes in the right atrium, generally the atrial appendage (RAA) and the right ventricular apex. The appendage, however, may be unsuitable if a stable position cannot be achieved. The aim of this study was to assess the haemodynamic consequences of different atrial stimulation sites during DDD pacing., Methods: In 12 consecutive patients (mean age 67 +/- 7 years) who underwent DDD pacemaker implantation, an additional temporary bipolar pacing electrode was positioned on the right atrial free wall. Pacing was performed alternating from the two locations at 85, 100 and 120 beats per minute (bpm). Paced atrioventricular delay was set at 180 ms. Cardiac output and mitral inflow measurements were performed using Doppler echocardiography., Results: Pacing at 85 and 100 bpm resulted in a significantly higher A-peak velocity from the RAA compared with the right atrial free wall. Cardiac index was consistently higher from the RAA location (2.4 +/- 1.2 vs 2.1 +/- 0.91. min-1 m-2 at 85 bpm, 2.71 +/- 1.4 vs 2.35 +/- 1.11. min-1 m-2 at 100 bpm and 2.94 +/- 1.5 vs 2.61 +/- 1.41. min-1 m-2 at 120 bpm, P < 0.05)., Conclusion: Stimulation from the RAA was superior to stimulation from the right atrial free wall with respect to left ventricular filling and cardiac output. Compared with stimulation from the right atrial free wall, RAA pacing resulted in an increase of 10-15% in cardiac output.

Electromagnetic interference of pacemaker systems has been well established and can lead to an inappropriate function of these devices. Recently, an implantable loop recorder (ILR) (REVEAL, Medtronic Inc.) has been introduced to evaluate the possible arrhythmic etiology of patients with recurrent syncope. We evaluated the interference of this device in two patients with implantable ILR and in three nonimplanted ILRs with four electromagnetic sources: cellular phones (GSMs), electronic article surveillance systems (EASs), metal detector gates (MDGs), and magnetic resonance imaging (MRI). The GSM did not affect appropriate function of the ILR whereas radiofrequency (RF) EAS could interfere with normal function in implanted and nonimplanted systems. The MDG had no influence on ILR function. The magnetic field induced by the MRI resulted in an irreversible error in one nonimplanted ILR. Therefore, although interference between electromagnetic sources and ILRs appears to be rare in our study, physicians should be aware of possible malfunctioning of these devices.

Background: This study investigated whether the extent of perfusion defect determined by intravenous myocardial contrast echocardiography (MCE) in patients with acute myocardial infarction (AMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) relates to coronary flow reserve (CRF) for assessment of myocardial reperfusion and is predictive for left ventricular recovery., Methods and Results: Twenty-five patients with first AMI underwent intravenous MCE with NC100100 with intermittent harmonic imaging before PTCA and after 24 hours. MCE before PTCA defined the risk region and MCE at 24 hours the "no-reflow" region. The no-reflow region divided by the risk region determined the ratio to the risk region. CFR was assessed immediately after PTCA and 24 hours later. Left ventricular wall motion score indexes were calculated before PTCA and after 4 weeks. CFR at 24 hours defined a recovery (CFR >/=1.6; n=17) and a nonrecovery group (CFR <1.6; n=8). Baseline CFR did not differ between groups. MCE ratio to the risk region was smaller in the recovery group compared with the nonrecovery group (34+/-49% vs 81+/-46%, P=0.009). A ratio to the risk region of

To prospectively assess the incidence and clinical significance of thromboembolic complications in patients with multiple (> or = 3) noninfected transvenous leads; 48 consecutive patients were evaluated. Half of the patients had two ventricular leads and one atrial lead, 15 patients had two atrial leads and one ventricular lead, while 9 patients had two ventricular and two atrial leads. No additional care was provided except for aspirin (80 mg bid) and annually performed echo-Doppler studies. Clinical follow-up included signs and symptoms of subclavian and/or axillary vein thrombosis, the presence of right congestive heart failure, the number of hospital admissions, and death. Echo-Doppler studies assessed the presence of an enlarged right atrium or ventricle, right atrial or ventricular spontaneous contrast, and the presence of tricuspid regurgitation. During a total follow-up of 7.4 +/- 2.2 years there were no differences in the incidence of clinical variables as compared to age-matched controls with DDD pacemakers. The most common complication was transient venous thrombosis (mostly presenting as venous prominence 1-2 weeks after implantation), which was seen in 17% of the study group versus 15% in controls (NS). Cumulative mortality was not different in both groups (13% in the study group vs 15% in controls). No differences were present with respect to hospital admissions (1.1 +/- 0.27/year in the study group vs 1.2 +/- 0.30/year in the controls). In patients with multiple ventricular leads, tricuspid regurgitation on echo-Doppler studies was more frequent (24%) as compared to controls (4%); however, clinical signs of right heart failure were equally distributed. Thus, patients with multiple (> or = 3) noninfected leads have no clinical adverse outcome during long-term follow-up.

Reliable atrial sensing is the prerequisite for restoration of atrioventricular synchrony in patients with single-lead VDD pacing systems. To determine echocardiographic variables associated with inappropriate atrial sensing, 21 consecutive patients with symptomatic second- or third-degree AV block and normal sinus node function were studied. Prior to implantation echocardiographic measurements of end-systolic and end-diastolic dimensions and volumes of the right atrium and right ventricle were performed. All patients underwent implantation of a Medtronic Thera VDD(d) pacemaker with a bipolar Medtronic Capsure electrode. A minimal amplitude of the unfiltered atrial electrocardiogram of > or =0.5 mV was required for permanent lead position and the atrial sensitivity was programmed below the lowest recorded value. Appropriate atrial sensing (atrial triggered ventricular paced complexes/total number of ventricular paced complexes) was assessed during 24-hour Holter monitoring and treadmill exercise testing 3 to 6 weeks after implantation. Inappropriate atrial sensing (<95% correct atrial synchronization during Holter registration and/or <97.5% during exercise testing) was present in nine patients. Right atrial volumes and the right ventricular end-diastolic volume was significantly higher, as compared to patients without inappropriate sensing (12 patients). The right atrial and diastolic volumes had the highest correlation with correct atrial sensing r = 0.83, P<0.0001). Using a postdefined cut-off value of > or =80 mL for the end-diastolic right atrial volume, sensitivity and specificity for inappropriate sensing was 100% and 92%, respectively. These findings show that preimplant echocardiography can identify patients with inappropriate sensing during VDD pacing, in whom DDD pacing should be considered.