[Show abstract][Hide abstract] ABSTRACT: In spite of the rapid development of medicine, cardiovascular diseases are still the number one killer in the world. In France every year more than 50,000 people die suddenly due cardiac arrhythmias. Identification of high risk sudden death patient is still a challenge. To detect the cardiac arrhythmias, currently Holter is generally used to record 1~3 leads ECG (electrocardiogram) signal during 24h to 72h. However the use of Holter is limited among the population due to its form factor (not user-friendly) and cost. In this paper, we propose an integrated single chip wearable Holter named SoC-Holter, which enables to record 1~4 leads ECG. This single chip SoC-Holter is relied on algorithm architecture adequation design methodology. To minimize energy consumption, CMOS technology (0.35Â¿m) is used to prototype the first implementation and test. The SoC-Holter has the following functions: signal conditioner and preamplifier, amplifier and filters, analog to digital converter, and nano-controller. The low pass filter is composed of current division, degeneration and common-mode feedback circuits added to fulfill the required performance. The analog circuits are implemented, tested and validated. The digital bloc is simulated, implemented and tested. It seems that an integrated, low cost, and user-friendly single chip Holter is feasible. Consequently large number of high risk populations such as heavy smoker and obese may be monitored.
[Show abstract][Hide abstract] ABSTRACT: Dilation of end-systolic and end-diastolic volumes (ESV, EDV) has been used to define left ventricular remodelling after acute myocardial infarction (MI), but the prognostic significance of different enlargement patterns has not been evaluated fully.
To analyse the evolution of left ventricular volumes and parameters of global and regional contractility and their correlations with long-term prognosis in patients treated by angioplasty in the acute phase of MI.
Seventy-four patients (mean age 56+/-13 years; 77% men), treated successfully by angioplasty in the acute phase of MI, were included prospectively. Significant enlargement of left ventricular volumes was defined as a greater than 20% increase between acute phase and 6-month control, assessed by contrast ventriculography. Clinical follow-up was obtained for all patients at 82+/-19 months.
Four groups were identified based on volume evolution: Group I (n=29, 39%; no volume enlargement); Group II (n=8, 11%; isolated EDV enlargement); Group III (n=10, 14%; isolated ESV enlargement); Group IV (n=27, 36%; ESV plus EDV enlargement). Global left ventricular ejection fraction increased in Groups I (p=0.001) and II (p=0.037), but decreased in Groups III (p=0.0002) and IV (p=0.019). The 6-year event-free survival rate was significantly (p=0.0039) better in Groups I and II (100%) than in Groups III and IV (80 and 78%, respectively).
ESV enlargement in patients with reperfused acute MI impacts negatively on long-term prognosis, while isolated EDV enlargement does not.
Full-text · Article · Aug 2009 · Archives of Cardiovascular Diseases
[Show abstract][Hide abstract] ABSTRACT: Thrombus aspiration devices have been shown to improve reperfusion criteria and to reduce distal embolization in patients treated by percutaneous coronary interventions (PCI) in the acute phase of ST-elevation myocardial infarction (STEMI). There are, however, little data about their efficacy in the reduction of infarct size.
We sought to assess in a prospective randomized trial the impact of thrombus aspiration on infarct size and severity and on left ventricular function in high-risk patients with a first STEMI. The primary end point was scintigraphic infarct size, and secondary end points were infarct severity and regional and global left ventricular function. Forty-four patients with completely occluded (Thrombolysis in Myocardial Infarction flow 0-1) proximal segments of infarct-related artery were randomly assigned to thrombus aspiration group with the Export catheter (n = 20) (Medtronic, Inc, Minneapolis, MN) or PCI-only group. A rest Tc-99-mibi gated single-photon emission computed tomographic and contrast-enhanced magnetic resonance imaging were performed 6 +/- 2 days later.
Infarct size was comparable in patients in the thrombus aspiration group and PCI-only group (30.6% +/- 15.8% vs 28.5% +/- 17.9% of the left ventricle, P = .7) as was infarct severity in infarct-related artery territory (55% +/- 12% vs 55% +/- 14%, P = .9). Transmurality score as assessed by magnetic resonance imaging was similar in both groups (2.03 +/- 1.05 vs 2.16 +/- 1.21, P = .7). There was no impact of thrombus aspiration on other secondary end points.
In our study, thrombus aspiration with the Export catheter performed as adjunctive therapy in high-risk patients with total occlusion of the proximal part of major coronary arteries does not decrease infarct size or severity and has no effect on left ventricular regional and global function.
No preview · Article · Apr 2009 · American heart journal
[Show abstract][Hide abstract] ABSTRACT: To analyze the reproducibility of LV volumes calculated by cardiac magnetic resonance imaging (CMRI) and to compare them to those obtained by conventional ventriculography.
A total of 30 patients with stable ischemic heart disease were prospectively included. Each underwent CMRI twice and ventriculography. Left ventricular end diastolic volume (EDV), end systolic volume (ESV) and LV ejection fraction (EF) were calculated by two radiologists at different level of experience. Intraobserver, interobserver and interstudy variabilities were assessed.
The cut off values were: intraobserver variability (EDV, ESV, EF): 9.4 ml, 5.3 ml, 3.3% for well-trained radiologist; 13.1 ml, 7.5 ml, 4.1% for less-trained radiologist. interobserver variability: EDV: 11.7 and 10.4 ml; ESV: 7.0 and 6.6 ml; EF: 3.9 and 4.2%. interstudy variability (EDV, ESV, EF): 11.6 and 12.6 ml, 7.1 and 7.4 ml, 3.9 and 3.5%, for experienced and less-trained observers. Statistical differences were found between CMRI and ventriculography: CMRI underestimation of EDV and EF, overestimation of ESV.
CMRI volumetric quantification of LV volumes and function is highly reproducible at different levels of experience, but not interchangeable with those obtained by ventriculography.
No preview · Article · Nov 2008 · Surgical and Radiologic Anatomy
[Show abstract][Hide abstract] ABSTRACT: The EVADEF registry enrolled 2296 patients implanted with a defibrillator between june 2001 and june 2003 and followed up 24 months. Their main characteristics were the following: their mean age was 60±15 years, they were male in 86 %. Their left ventricular ejection fraction was 38.9 ± 15.9 %. They were in NYHA class I or II for 83.8% of them, in class III for 14.7% and in class IV for only 1.5%. Secondary prevention indications concerned 82.1%, primary prevention 18.3%. Underlying cardiopathies were coronary artery disease in 61.3%, dilated cardiomyopathies in 15.9%. In a group of 7.1% there was no underlying heart disease. The implanted devices were VVI in 48.3%, DDD in 42.9%, biventricular pacemaker with defibrillator in 8.3% and dual defibrillator in 0.5%. Periprocedure complications concerned 13.8%. The most frequently reported was the presence of an haematoma. Periprocedure mortality concerned 8 patients, i.e. 0.3% of the total cohort. Mortality was 7.2% at 1 year and 11.3% at 2 years. Among the 274 deaths, a majority was due to heart failure (42%), arrhythmic storms represented only 6.2% of deaths. Hopefully it is likely that in the future association of cardiac resynchronization therapy to defibrillator will be able to decrease this death rate due to heart failure.
[Show abstract][Hide abstract] ABSTRACT: Recently, cell replacement therapy has been investigated as a new tool in patients with ischaemic heart disease (IHD), who are prone to or with already established systolic dysfunction. Different subsets of stem cells have been used for preventive as well as curative purposes. Although cardiac cell transplantation and cytokine mobilization originally began in clinical trials with the explicit goal of myocardial regeneration, more recently, the emphasis has been focused on remodelling attenuation capacities of this approach. Left ventricular (LV) remodelling is a complex process involving changes in size, shape, and function of the LV, which plays an important role in the development of chronic heart failure after acute myocardial infarction (AMI). Recently, several studies have improved our knowledge about prevalence, clinical importance, and methods predicting the occurrence of LV remodelling after AMI. In patients with established LV remodelling, the place of cell replacement therapy is to be assessed in function of recent progresses concerning the selection of patients for revascularization therapy as well as for other surgical and electrical methods. This article deals with the possibilities of screening of patients with IHD for cell replacement therapy.
Full-text · Article · Dec 2006 · European Heart Journal Supplements
[Show abstract][Hide abstract] ABSTRACT: More than 60,000 people die suddenly each year in France due to cardiac arrhythmias. The current techniques used to diagnose cardiac arrhythmias such as HOLTER, R.TEST and telemetry system are partially efficient owing to the limitation of the duration of monitoring. This paper presents a new system dedicated to real-time cardiac arrhythmias tele- assistance and monitoring. This system is generally composed of 4 main configurable elements: wireless ECG sensor, local access unit, remote centre server, and remote surveillance terminal. The main technical challenges of this system include three aspects: a real-time automatic ECG diagnostic algorithm, an embedded real-time multi-task operating system, and a real-time reliable telemedicine communication protocol. This paper gives our solutions to these problems and specifies the technical details. Currently, this system has been evaluated on thirty patients at the CHRU of Gabriel Montpied hospital (Clermont-Ferrand, France) and also been used to test the athletes' cardiac status during the physical exercises. The performance results show that this system meets fully the requirements of real-time cardiac monitoring and diagnosing application and can be used as a long-term cardiac healthcare equipment.
[Show abstract][Hide abstract] ABSTRACT: Recently, Japanese authors have described a new clinical entity associating apical akidyskinesia and basal hyperkinesias without significant coronary artery disease under the name of the tako-tsubo syndrome. This syndrome is usually observed in elderly women and the clinical presentation is usually that of an acute coronary syndrome. The authors report 10 cases of patients investigated between June 2003 and August 2004. All patients were women with an average age of 66 +/- 15 years. Seven patients had chest pain on admission with, in three cases, signs of cardiac failure. In 8 patients, a causal factor was identified: emotional stress in 7 cases and anaphylactic shock in one case. All patients underwent coronary angiography and ventriculography which showed typical changes in left ventricular contractility without significant coronary disease. The peak CPK and troponin values were 222 +/- 115 UI/l and 3.32 +/- 1.50 microg/l, respectively. One patient died in cardiogenic shock. In the other cases, normalisation of wall motion was observed in the month following the onset of symptoms. One patient developed 3rd degree atrioventricular block and required implantation of a pacemaker. This clinical entity must be taken into consideration in elderly women with acute coronary syndromes.
No preview · Article · May 2005 · Archives des maladies du coeur et des vaisseaux
[Show abstract][Hide abstract] ABSTRACT: Cardiac arrhythmia is a class of serious heart diseases that threatens many people. Current arrhythmias diagnostic techniques seem to be partially efficient due to the application limitations either in time or in space. The paper presents a real-time continuous arrhythmias detection system (RECAD) platform based on the wireless sensor network technology. This system provides long-term real-time surveillance thanks to the low-resource and low power consumptions of ambulatory wireless ECG sensor (AWES). Moreover, the AWES is compact and friendly use, so it enables patients to lead a normal life every where (indoors or outdoors). RECAD platform contains four sub-systems: AWES, local access server, remote access server and remote surveillance server. Each subsystem is configurable to run in multiple operation modes according to different application scenarios. A lossless signal compression algorithm is adopted to reduce network traffics and a dedicated application layer protocol is provided to guarantee a real-time reliable on-line ECG analysis. This system is evaluated on about twenty patients at the hospital Gabriel Montpied of Clermont-Ferrand and the real-time results are similar to the HP telemetry system.
No preview · Article · Feb 2005 · Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference
[Show abstract][Hide abstract] ABSTRACT: The Wireless sensor networks (WSN) technology is one of the most powerful technologies that will shape science and engineering in the 21st century. It combines the capabilities of sensing, computation and wireless connection. It is an interesting yet challenging job to apply the WSN technology on the traditional healthcare field. Realizing a WSN system presents very significant challenges, especially at the architectural, the operation system, protocol/software level and the application support. This paper presents a WSN system dedicated to remote continuous real-time cardiac arrhythmias detection and diagnosis. Major steps forward to the WSN telemedicine application are presented in this paper: a low cost, low energy consuming and compact wireless ECG sensor named WES corresponding to the AHA recommendations; a super-small real-time multi-task micro kernel named SDREAM having tiny resource consumption and supporting real-time multi-task operation; a minimal real-time TCP/IP stack named uRET corresponding to the standard RFCs and the modular architecture, having minimal resource consumption and connecting WSN nodes with Internet; a real-time cardiac arrhythmia detection and diagnosis algorithm adopting the geometric modeling method and the expert system method that simplifies the implementation and improves the algorithm performance; a remote telemedicine platform named STAR providing a interface-friendly and visualization interface that supports multi-operation modes in varying application scenarios. Finally, this paper presents the application instance of the STAR platform at the CHRU of Gabriel Montpied hospital of Clermont-Ferrand (France) and gives the performance results.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to assess the value of technetium 99m sestamibi gated single photon emission computed tomography (SPECT) in predicting the evolution of left ventricular volumes in patients treated successfully in the acute phase of a myocardial infarction (MI).
Twenty-nine patients with acute MI and early percutaneous transluminal coronary angioplasty (PTCA) were included in this study. A rest Tc-99m sestamibi electrocardiography (ECG)-gated SPECT study was performed 21 +/- 5 days after PTCA. The myocardial perfusion index was calculated by use of a semiautomatic sectorial analysis. All patients had contrast ventriculography performed during the acute phase and 6 months later. The patients were separated into two groups according to the absence (group I, n = 21) or presence (group II, n = 8) of end-systolic enlargement. The perfusion index in the infarct sectors was -2.29 +/- 2.90 SD in group I and -6.40 +/- 2.85 SD in group II ( P < .01). With a cutoff value of -2.46 SD, the sensitivity and specificity of Tc-99m sestamibi SPECT for the prediction of end-systolic volume enlargement were 100% and 62%, respectively. When the functional data from ECG-gated acquisitions were added, specificity increased to 86%.
Despite successful PTCA in the acute phase of MI, an increase in end-systolic volume was observed at 6 months in 28% of patients. Tc-99m sestamibi ECG-gated SPECT performed 3 weeks after the acute phase could predict this enlargement with a high accuracy.
No preview · Article · Dec 2004 · Journal of Nuclear Cardiology
[Show abstract][Hide abstract] ABSTRACT: To define a subgroup of patients at increased risk of renal artery stenosis (RAS) in a population of patients undergoing cardiac catheterization.
A total of 467 patients (mean age of 64 Years +/-11) underwent cardiac catheterization and aortography Results were evaluated to detect correlations between the presence or absence of RAS and clinical and biological parameters.
A total of 42 (9%) patients had a renal artery stenosis. Univariate analysis defined parameters correlated with the presence of RAS: systolic blood pressure (p=0.03), pulse pressure (p=0.005), age (p<0.0001), creatinine clearance (p<0.0001), 2-vessel (p=0.028) and 3-vessel (p=0.037) coronary artery diseases. Multivariate analysis showed that the presence of RAS correlated to creatinine clearance (p=0.02) and 2-vessel coronary artery disease. A creatinine clearance between 30 and 60 ml/min and multi-vessel coronary artery disease defined a subgroup at increased risk of RAS with sensitivity, specificity, positive and negative predictive values of: 47.6, 90.1, 32.3 and 94.6%. The prevalence of renal artery stenosis was 5.2% when both parameters were absent.
Patients with mild renal insufficiency and multi-vessel coronary artery disease defined a subgroup of patients at increased risk of RAS (32.5%) that may benefit from abdominal aortography performed at the time of cardiac catheterization.
No preview · Article · May 2004 · Journal de Radiologie
[Show abstract][Hide abstract] ABSTRACT: To retrospectively evaluate the contribution of MRI to the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD).
Thirty two men and 18 women (mean age: 48.7 years) were imaged using gated spin echo scans and short axis cine MR. References were McKenna criteria (gold standard), and also what we called "strong presumption" which may correspond to early or localized patterns, but correspond to negative McKenna scores.
One patient was claustrophobic; another one was lost to follow-up. In reference to McKenna score, diagnosis of ARVD was established in 12 patients (2 of whom had familial dilated biventricular cardiomyopathy with rhythmic expression). Sensitivity, specificity, positive predictive value, negative predictive value and prevalence were respectively: 75%, 75%, 50%, 90% and 25%. Using "strong presumption" criteria, we observed 14 true positives (with sensitivity of 82%, specificity of 87%, PPV of 78%, NPV of 90% and prevalence of 35%).
In our group, MRI was always performed before angiography. In our series, right ventricular wall T1W hyperintensity was the most frequent finding.
No preview · Article · Apr 2004 · Journal de Radiologie