after a 12-week swimming training program. In the swimming group (6 male and 6 female rats), swim... more after a 12-week swimming training program. In the swimming group (6 male and 6 female rats), swimming time was increased to 200 minutes per session 5 days per week, while the control group (6 male and 6 female rats) swam 5 minutes a day 5 days a week. After preparation of the arteries, we studied their reactivity to pressure (μm 0-150 mmHg) with a microangiometer in normal Krebs and noradrenalin medium. External and internal diameter and wall thickness were measured on videomicroscope images. Differences were tested with 2-way ANOVA. Significance was set at p<0.05. Results: Male and female trained groups had lower body weight (male: 417.5±27.6g vs. 470.5±21.0g and female: 283.1±13.3g vs. 289.2±14.8g, p<0.001) and higher heart weight (male: 1.64±0.24g vs. 1.59±0.09g and female: 1.27±0.10g vs 1.09±0.05g, p<0.001) compared to controls. In the male control group, the external diameter of gracilis artery was the smallest and significantly smaller compared to the female controls (177.3±21.0μm vs. 245.5±10.7μm, p<0.0001) and the swimming males (177.3±21.0μm vs. 229.2±26.7μm, p<0.001). Male controls have the greatest wall thickness which was significantly greater compared to the female controls (25.9±2.4μm vs. 16.9±1.4μm, p<0.001). There was no difference in wall thickness between male and female swimming groups. In line with our results of the artery morphology, the reactivity to pressure in the noradrenalin medium was the lowest in male controls compared to the other groups. Distensibility was significantly higher in swimming groups compared to controls. Conclusions: As a result of regular exercise, structural and functional remodeling can be observed on gracilis artery, as "athlete's artery". Male trained rats showed more pronounced vascular adaptation to exercise with increased external diameter and decreased wall thickness versus trained females. Differences in proportion of muscle and elastic fibers, and hormonal and autonomic mechanisms may be responsible for these characteristic vascular adaptation changes.
In this study we propose a novel approach, based on multiple correspondences analysis (MCA), to i... more In this study we propose a novel approach, based on multiple correspondences analysis (MCA), to identify the relationships between the spectral variables obtained from HRV signals and those from ventricular repolarization variability (VRV). Parameters were extracted from RR and RT time series from 47 ECG records from aerobic and anaerobic sportsmen and sedentary subject. These numerical variables were transformed in categorical variables using a 7 classes fuzzy coding and several MCA were carried out. Results show that: i) aerobic disciplines present more variability than anaerobic ones, ii) mean RT interval are longer in sportsmen than in control subjects, iii) only the low frequencies of the HRV and VRV series are correlated, evidencing the heart rate modulation on ventricular repolarization, iv) the high frequencies of the RT space seem to be inadequate markers for the characterization of the ANS modulation on ventricular repolarization.
Sports activity may modify cardio-vascular regulation through the Autonomic Nervous System, the r... more Sports activity may modify cardio-vascular regulation through the Autonomic Nervous System, the results of the studies previously performed in athletes depend on the type of HRV analysis is subjected to, the populations studied and the physical training period. The drawback of these studies comes from an analysis parameter by parameter whereas the problem is inherently multifactorial. A method based on multiple factorial analysis is proposed in this study. Multivariate analysis results confirmed the existence of differences in the ANS in athletes depending on the training period and the sport discipline. Multiple Factorial Analysis provides a very powerful tool allowing the confrontation of² whole information, which is more rich than an examination parameter by parameter to assess autonomic nervous system.
2013 1st International Conference on Communications, Signal Processing, and their Applications (ICCSPA), 2013
ABSTRACT The aim of this paper is to improve the physiological understanding in order to differen... more ABSTRACT The aim of this paper is to improve the physiological understanding in order to differentiate between the two types of vasovagal syncope by performing a Head-up Tilt Test. The Head-up Tilt Test is a well known procedure to reproduce vasovagal syncope, patients who had syncope during the test show different orthostatic response depending on they are cardioinhibitory or vasodepressor patients which can be explain by different pathogeneses, although existing knowledge of the autonomic balance in patients with positive response is still not completely clear. The Electrocardiogram signal from 20 patients, 12 cardioinhibitory and 8 vasodepressor were analyzed with the validated software Segmenta (Laboratory of Signal and Image Processing, Rennes) to extract classical heart rate variability parameters then comparison were made within and between group for 5 minutes of resting, the first 5 minutes of the tilt test and the last 5 minutes before syncope. The Results show that Cardioinhibitory patients had higher low frequency parameter in the last 5 minutes before syncope than vasodepressor patients (p
European Heart Journal - Cardiovascular Imaging, 2014
Introduction: The increase of left auricular volume (LAV) is a robust cardiovascular event predic... more Introduction: The increase of left auricular volume (LAV) is a robust cardiovascular event predictor. Despite that echochardiography is more often used, cardiac MRI is considered more accurate. Our objetives are to validate "fast" LAV measures by MRI vs the considered gold standard (GS) and to compare Echo and MRI in a wide spectrum of patients. Methods: In a non-selected popullation with MRI study previously realized, we measured LAV by biplane method (BPMR) and by area-length in 4 chamber view (ALMR) and compared them with biplane (BPe) and discs method (MDDe) in 4 chamber view in echo. To validate MRI measurements, we measured LAV in short axis slices (Simpson Method, SM) in a group of patients and considered it the GS. Results: 186 patients were included (mean age 51 + 17 age; 123 male; 14 in AF) with clinical indication of cardiac MRI (Philips 1,5 T). In 24 patients SM was calculated. 29% of cardiac MRI were considered normal. Mean underlying pathologies were myocardiopathy (27%), Ischemic myocardiopathy (17%), myopericarditis (10%), prior to AF ablation (4%), valvular disease (6%) and miscellaneous (7%). Excellent correlation was obtained between "fast" MRI measurements and SM in MRI (SM vs BPMR interclass correlation coefficient ICC=0.965 and SM vs ALMR, ICC=0.958; P,0.05) with low interobserver variability (ICC=0.983 for SM; ICC=0.949 for BPMR; ICC=0.931 for ALMR). "Fast" measurements by MRI showed stadistical correlation between them (CCI=0.910) (Figure). Correlation between Echo and MRI measures was only moderate. (BPRM vs BPe CCI=0,469 mean difference-30 ml; ALMR vs MDDe ICC=0,456 mean difference-24 mL). Conclusions: 'fast' LAV measures by MRI are comparable with the MRI GS and also between them. Echo values seem to underestimate compared to MRI, so its use may not be suitable.
European Heart Journal - Cardiovascular Imaging, 2014
Clinical PETacquisitions of the heart suffer from artefacts and drops in image quality due to the... more Clinical PETacquisitions of the heart suffer from artefacts and drops in image quality due to the poor spatial resolution of the PET system. Moreover, cardiac PET images are further degraded by the blur caused by the breathing and beating motions, thus hampering diagnosis and evaluation of myocardial pathologies. Anatomy-enhanced PET reconstruction, using a high-resolution CT, has proven useful in brain imaging. In cardiac datasets however, due to the motion artefacts, the application of any restoring technique on datasets affected by motion blur needs to be preceded by the validation of the proposed method on realistic static datasets. In this work, the validation is performed using static cardiac ex vivo datasets obtained from a number of sacrificed sheep, scanned on a clinical PET/CTscanner. The aim of this work is to assess the effectiveness of reconstructions of the acquired datasets with different CTbased anatomical priors, in comparison to reconstructions currently applied in clinical practise. The gold standard to which all reconstructions are compared consists of images of the same hearts scanned on a small-animal PET scanner, whose high spatial resolution allows for almost artefact-free images. Encouraging results were obtained so far, with improvements in volume delineation and uniformity of activity values when anatomical information was used. Fig 1 shows the gold standard image (left) compared to a regular clinical reconstruction (middle) and to a reconstruction using the high-resolution CT as anatomical information (right).
Introduction: Transoesophageal echocardiography (TOE) has become routine during cardiac surgery f... more Introduction: Transoesophageal echocardiography (TOE) has become routine during cardiac surgery for evaluation of cardiac function and valve morphology prior and after repair of cardiac disease. Major complications of TOE are reported to be rare, especially in the hands of experienced investigators. However,a TOE probe might cause minor injuries in the stomach, especially if the procedure takes several hours. We therefore hypothesized that minor injuries are a common sequel of long-time TOE during cardiac surgery. Material and Methods: After induction of anesthesia in patients undergoing elective cardiac interventions, endoscopy of pharynx, esophagus and stomach was performed in order to exclude any previous lesion. A TOE probe was then inserted as part of the routine procedure and left in place until the operation was finished and the patient in stable condition to be transferred to the intensive care unit. The TOE probe was then removedand endoscopy was performed a second time to detect any new lesions in the stomach. All lesions of the mucosa were documented (type, localization, and number) as well the time needed for the TOE examinations before and after the cardiopulmonary bypass (CPB). Data are expressed as mean + standard deviation. Results: After approval of the Ethics committee and obtaining informed consent ten patients were included in our study. Duration of TOE probes in situ was 453 + 20 minutes. Of the ten patients included in the study only 1 patient had no lesion. In two patients only 1 lesion and in the others more than one could be detected. Five patients had 2 lesions and the last 2 patients had 3 and 4 lesions, respectively (1,9 + 1,1 lesions per patient). Most of the lesions were localized in the esophagus (10) and in the stomach (6); 2 lesions were detected in the pharynx and 1 lesion in the gastroesophageal junction. Most of the lesions were petechiae (9) and hematomas (6), while mucosal erosions and erythemas were present only two times. Severe lesions could not be detected. Conclusions: Our results have shown that minor injuries are caused frequently by TOE probes where the oesophageal and gastric mucosa are the most involved areas. A bigger sample size is needed to confirm if a longer duration the TOE probe in situ (more than 7 hours) is associated with more lesions. Furthermore, more lesions could also affect ICU and hospital length of stay.
European Heart Journal - Cardiovascular Imaging, 2013
Is there any association between systemic vascular reactivity and pulmonary artery pressure in pa... more Is there any association between systemic vascular reactivity and pulmonary artery pressure in patients with common forms of pulmonary hypertension?
This study aims to analyze the autonomic nervous system response during head-up tilt test (HUTT),... more This study aims to analyze the autonomic nervous system response during head-up tilt test (HUTT), by exploring the changes in dynamic properties of heart rate variability in subjects with and without syncopes, to predict the outcome of HUTT. Baroreflex response, as well as linear and non-linear parameters of RR-interval time series, have been extracted from the ECG of 66 subjects: 35 with and 31 without syncope during HUTT. The results show that, when considering the first 15 min of tilting position, the total power spectrum, the standard deviation, the long-term fractal scale of RR-interval and ΔRR-interval of time series increase, while the sample entropy decreases in the positive group compared to the negative one. These indices may be good predictors of positive response in patients with reflex syncope. Additionally, an analysis of the first 15 min of tilting position using kernel support vector machines leads to a correct classification of 85% of patients, within negative and p...
Cardiovascular remodelling in the conditioned athlete is frequently associated with physiological... more Cardiovascular remodelling in the conditioned athlete is frequently associated with physiological ECG changes. Abnormalities, however, may be detected which represent expression of an underlying heart disease that puts the athlete at risk of arrhythmic cardiac arrest during sports. It is mandatory that ECG changes resulting from intensive physical training are distinguished from abnormalities which reflect a potential cardiac pathology. The present article represents the consensus statement of an international panel of cardiologists and sports medical physicians with expertise in the fields of electrocardiography, imaging, inherited cardiovascular disease, cardiovascular pathology, and management of young competitive athletes. The document provides cardiologists and sports medical physicians with a modern approach to correct interpretation of 12-lead ECG in the athlete and emerging understanding of incomplete penetrance of inherited cardiovascular disease. When the ECG of an athlete is examined, the main objective is to distinguish between physiological patterns that should cause no alarm and those that require action and/or additional testing to exclude (or confirm) the suspicion of an underlying cardiovascular condition carrying the risk of sudden death during sports. The aim of the present position paper is to provide a framework for this distinction. For every ECG abnormality, the document focuses on the ensuing clinical work-up required for differential diagnosis and clinical assessment. When appropriate the referral options for risk stratification and cardiovascular management of the athlete are briefly addressed.
Niferidile (NF) is new Russian class III antiarrhythmic agent. Electrophysiological studies showe... more Niferidile (NF) is new Russian class III antiarrhythmic agent. Electrophysiological studies showed, that NF increased refractory periods much higher in atria than in ventricles, didn't influence parameters of sinus function, intra-, interatrial and AV-conductance. Aime: to study effects of NF 10, 20 and 30 mg/kg at main ECG characteristics (QT, QTc, QRS, ff and RR intervals) after conversion of persistent atrial fibrillation (AF) and flutter (AFL) to sinus rhythm (SR). Methods: 100 pts (64 male), age 58 + 12 years, with arrhythmia lasting 4,2 + 3,9 months (1 week-24 months) were included. 82 pts had AF and 18 AFL. Holter ECG recorder was activated 1 h before NF infusion. NF was administered as 3 i.v. bolus injections (10 mg/kg each) performed with the 15-min interval. If SR was restored within 15 min after injection, the next injection was cancelled. Successful conversion was defined as restoration of SR within 24 h after beginning of the treatment. Results: Cardioversion success rate of NF in dose of 10 mg/kg was 49%, in dose of 20 mg/kg it was 65%, and in dose of 30 mg/kg reached 88%. In 1 patient after infusion of 10 mg/kg of NF QT interval prolongated up to 700 ms and unsustained runs of polymorphyc ventricular tachycardia of 3-9 complexes were registrated during 15 min. This patient converted to normal SR in 22 h after NF infusion. Mean QT and QTc after NF infusion prolongated in dose-dependent manner. QT returned to normal meanings within 3 h in pts, who received 10 mg/kg and only within 22-23 h in pts, who received 20 or 30 mg/kg of NF. QTc interval in pts, who received 10 mg/kg reached normal value after 21 h and didn't return to normal meanings till the end of observation period in those who received 20 or 30 mg/kg. QT and QTc intervals in pts, who was given 20 or 30 mg/kg of NF, didn't differ significantly among themselves and exceeded appropriate meanings of those pts, who got 10 mg/kg of NF during all period of monitoring. NF caused increase of ff length, frequent transformation of AF to AFL, which typically preceded SR restoration. RR intervals after SR restoration didn't differ significantly between 3 groups of pts within 24 h. No effect was noted on the duration of the QRS interval in pts received different doses of NF. Conclusions: NF causes dose-dependent moderate prolongation of mean QT and QTc, doesn't influence RR and QRS intervals, regulates atrial activity and increases ff duration. I.v. NF in doses up to 30 mg/kg seems to be very effective in conversion of patients with persistent AF and AFL and proarrhythmic events are rare.
Background— Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studi... more Background— Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studies in black male athletes reveal a higher prevalence of electric repolarization and left ventricular hypertrophy than observed in white males; these frequently overlap with those observed in cardiomyopathy and have important implications in the preparticipation cardiac screening era. There are no reports on cardiac adaptation in highly trained black females, who comprise an increasing population of elite competitors. Methods and Results— Between 2004 and 2009, 240 nationally ranked black female athletes (mean age 21±4.6 years old) underwent 12-lead ECG and 2-dimensional echocardiography. The results were compared with 200 white female athletes of similar age and size participating in similar sports. Black athletes demonstrated greater left ventricular wall thickness (9.2±1.2 versus 8.6±1.2 mm, P <0.001) and left ventricular mass (187.2±42 versus 172.3±42 g, P =0.008) than white athlet...
Regular participation in intensive physical exercise is associated with several structural and el... more Regular participation in intensive physical exercise is associated with several structural and electrophysiological cardiac adaptations that enhance diastolic filling and facilitate a sustained increase in the cardiac output that is fundamental to athletic excellence. Such cardiac adaptations are collectively referred to as the ' Athlete's Heart' and are frequently reflected on the 12-lead ECG and imaging studies. Thorough knowledge relating to exercise-associated cardiovascular adaptation is imperative for the purposes of differentiating physiological adaptation from cardiac pathology, since an erroneous diagnosis of cardiac disease has potentially serious consequences for the athlete's physical, psychological, social and financial well-being. The majority of studies investigating the cardiovascular adaptation to exercise are based on cohorts of Caucasian athletes. However, there is mounting evidence that ethnicity is an important determinant of the objective manifestations of cardiovascular adaptation to exercise. The most pronounced paradigm of ethnically distinct cardiovascular adaptation to exercise stems from athletes of African/ Afro-Caribbean descent, who exhibit a significantly higher prevalence of repolarisation anomalies and left ventricular hypertrophy, compared to Caucasian athletes; the differentiation between athlete's heart and hypertrophic cardiomyopathy is particularly challenging in this ethnic group. The extrapolation of ECG and echocardiographic criteria used to diagnose potentially serious cardiac disorders in Caucasian athletes to the African/Afro-Caribbean athlete population would result in an unacceptable number of unnecessary investigations and increased risk of false disqualification from competitive sport. Accurate interpretation of the athlete's ECG and echocardiogram is crucial, particularly when one considers the continuous expansion of preparticipation screening programmes. This review attempts to highlight ethnically determined differences in cardiovascular adaptation to exercise and provides a practical guide for the interpretation of baseline investigations in athletes of diverse ethnic backgrounds.
Background.-Heart failure (HF) with a preserved (P) left ventricular (LV) ejection fraction (EF) ... more Background.-Heart failure (HF) with a preserved (P) left ventricular (LV) ejection fraction (EF) is common, though its diagnosis and physiopathology remain unclear. We sought to compare the myocardial characteristics at rest and during submaximal exercise in patients with HFPEF and in controls. Methods.-Standardized submaximal exercise stress echocardiography was performed in (a) 36 patients from the KaRen HFPEF-registry, whose LV EF was ≥ 45%, and (b) 10 control patients free from manifestations of HF. Results.-During submaximal exercise LV-systolic function measured as global 4-chamber longitudinal strain was −17.2 ± 4.7% in patients with HFPEF versus −23.7 ± 3.1% in controls (P < 0.001), LV longitudinal diastolic function, expressed as e' was 9.9 ± 2.8 cm/s in patients, versus 14.5 ± 3 cm/s in controls (P < 0.001), and RV longitudinal systolic function, expressed as RVs', was 13.3 ± 3.5 cm/s in patients versus 17.7 ± 1.5 cm/s in controls (P < 0.05). LV afterload (arterial elastance was 2.6 ± 1 mmHg/ml in patients versus 0.8 ± 1.4 mmHg/ml in controls; P < 0.001) was significantly higher in the HFPEF than in the control group, and was correlated with a decrease in LV longitudinal strain (R = 0.63, P < 0.001) during exercise. Conclusion.-Significant abnormalities of LV-systolic and diastolic functions were revealed by exercise stress echocardiography in patients recently admitted for heart failure and with a preserved LVEF. These observations help clarifying persisting uncertainties regarding diastolic and systolic function in HFPEF and may help in selecting therapy for such patients.
The two air-stable m 2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluoro... more The two air-stable m 2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate complexes were successfully synthesized. The high catalytic activity and recyclability of these complexes were exemplified for various carbon-carbon bond formation reactions. Compared with our previously reported hafnocene perfluorooctanesulfonate, these complexes show stronger Lewis acidity and better catalytic activity, and should find broad applications in organic synthesis.
≥ 4 segments). Among these patients, 19 (10.7%), had no significant coronary artery stenosis. Thi... more ≥ 4 segments). Among these patients, 19 (10.7%), had no significant coronary artery stenosis. This group included eight men (42%). Stress echo was performed during exercise in 17 patients and using dobutamine in 2. Peak systolic blood pressure was 193 ± 31 mmHg in these patients vs 193 ± 34 mmHg in patients with a large ischemic area (≥ 4 segments) but with significant coronary artery stenosis on angiography (ns). Conclusion.-The item ''false positive'' stress echo must be discussed since nearly 10% of patients with a large ischemic area during the test have non significant coronary artery lesion. In our study, these patients were more often women evaluated during exercise. Systolic blood pressure level does not explain the WMA observed during the test.
2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008
The aim of the present study was to evidence that the heart reinnervation can occur and it is rel... more The aim of the present study was to evidence that the heart reinnervation can occur and it is related with the time after transplantation (evolution with time). Data were evaluated using Multiple Correspondence Analyses (MCA), which is the ideal method to study the relation, probably nonlinear, between the Time After Transplantation (TAT) and the probable restoration of normal heart rate responses of sinus node regulated by the autonomic nervous system. Twenty four nonrejecting transplant recipients (60 +/- 48 months after transplantation) and nine healthy subjects were studied by heart rate variability parameters. Results showed that sympathetic activity is restored some time after transplantation. Until 48 months, the recent HTR are in direct correlation to low values SD and LF and for the oldest transplant recipient, these parameters are similar to that observed in normal subjects.
after a 12-week swimming training program. In the swimming group (6 male and 6 female rats), swim... more after a 12-week swimming training program. In the swimming group (6 male and 6 female rats), swimming time was increased to 200 minutes per session 5 days per week, while the control group (6 male and 6 female rats) swam 5 minutes a day 5 days a week. After preparation of the arteries, we studied their reactivity to pressure (μm 0-150 mmHg) with a microangiometer in normal Krebs and noradrenalin medium. External and internal diameter and wall thickness were measured on videomicroscope images. Differences were tested with 2-way ANOVA. Significance was set at p<0.05. Results: Male and female trained groups had lower body weight (male: 417.5±27.6g vs. 470.5±21.0g and female: 283.1±13.3g vs. 289.2±14.8g, p<0.001) and higher heart weight (male: 1.64±0.24g vs. 1.59±0.09g and female: 1.27±0.10g vs 1.09±0.05g, p<0.001) compared to controls. In the male control group, the external diameter of gracilis artery was the smallest and significantly smaller compared to the female controls (177.3±21.0μm vs. 245.5±10.7μm, p<0.0001) and the swimming males (177.3±21.0μm vs. 229.2±26.7μm, p<0.001). Male controls have the greatest wall thickness which was significantly greater compared to the female controls (25.9±2.4μm vs. 16.9±1.4μm, p<0.001). There was no difference in wall thickness between male and female swimming groups. In line with our results of the artery morphology, the reactivity to pressure in the noradrenalin medium was the lowest in male controls compared to the other groups. Distensibility was significantly higher in swimming groups compared to controls. Conclusions: As a result of regular exercise, structural and functional remodeling can be observed on gracilis artery, as "athlete's artery". Male trained rats showed more pronounced vascular adaptation to exercise with increased external diameter and decreased wall thickness versus trained females. Differences in proportion of muscle and elastic fibers, and hormonal and autonomic mechanisms may be responsible for these characteristic vascular adaptation changes.
In this study we propose a novel approach, based on multiple correspondences analysis (MCA), to i... more In this study we propose a novel approach, based on multiple correspondences analysis (MCA), to identify the relationships between the spectral variables obtained from HRV signals and those from ventricular repolarization variability (VRV). Parameters were extracted from RR and RT time series from 47 ECG records from aerobic and anaerobic sportsmen and sedentary subject. These numerical variables were transformed in categorical variables using a 7 classes fuzzy coding and several MCA were carried out. Results show that: i) aerobic disciplines present more variability than anaerobic ones, ii) mean RT interval are longer in sportsmen than in control subjects, iii) only the low frequencies of the HRV and VRV series are correlated, evidencing the heart rate modulation on ventricular repolarization, iv) the high frequencies of the RT space seem to be inadequate markers for the characterization of the ANS modulation on ventricular repolarization.
Sports activity may modify cardio-vascular regulation through the Autonomic Nervous System, the r... more Sports activity may modify cardio-vascular regulation through the Autonomic Nervous System, the results of the studies previously performed in athletes depend on the type of HRV analysis is subjected to, the populations studied and the physical training period. The drawback of these studies comes from an analysis parameter by parameter whereas the problem is inherently multifactorial. A method based on multiple factorial analysis is proposed in this study. Multivariate analysis results confirmed the existence of differences in the ANS in athletes depending on the training period and the sport discipline. Multiple Factorial Analysis provides a very powerful tool allowing the confrontation of² whole information, which is more rich than an examination parameter by parameter to assess autonomic nervous system.
2013 1st International Conference on Communications, Signal Processing, and their Applications (ICCSPA), 2013
ABSTRACT The aim of this paper is to improve the physiological understanding in order to differen... more ABSTRACT The aim of this paper is to improve the physiological understanding in order to differentiate between the two types of vasovagal syncope by performing a Head-up Tilt Test. The Head-up Tilt Test is a well known procedure to reproduce vasovagal syncope, patients who had syncope during the test show different orthostatic response depending on they are cardioinhibitory or vasodepressor patients which can be explain by different pathogeneses, although existing knowledge of the autonomic balance in patients with positive response is still not completely clear. The Electrocardiogram signal from 20 patients, 12 cardioinhibitory and 8 vasodepressor were analyzed with the validated software Segmenta (Laboratory of Signal and Image Processing, Rennes) to extract classical heart rate variability parameters then comparison were made within and between group for 5 minutes of resting, the first 5 minutes of the tilt test and the last 5 minutes before syncope. The Results show that Cardioinhibitory patients had higher low frequency parameter in the last 5 minutes before syncope than vasodepressor patients (p
European Heart Journal - Cardiovascular Imaging, 2014
Introduction: The increase of left auricular volume (LAV) is a robust cardiovascular event predic... more Introduction: The increase of left auricular volume (LAV) is a robust cardiovascular event predictor. Despite that echochardiography is more often used, cardiac MRI is considered more accurate. Our objetives are to validate "fast" LAV measures by MRI vs the considered gold standard (GS) and to compare Echo and MRI in a wide spectrum of patients. Methods: In a non-selected popullation with MRI study previously realized, we measured LAV by biplane method (BPMR) and by area-length in 4 chamber view (ALMR) and compared them with biplane (BPe) and discs method (MDDe) in 4 chamber view in echo. To validate MRI measurements, we measured LAV in short axis slices (Simpson Method, SM) in a group of patients and considered it the GS. Results: 186 patients were included (mean age 51 + 17 age; 123 male; 14 in AF) with clinical indication of cardiac MRI (Philips 1,5 T). In 24 patients SM was calculated. 29% of cardiac MRI were considered normal. Mean underlying pathologies were myocardiopathy (27%), Ischemic myocardiopathy (17%), myopericarditis (10%), prior to AF ablation (4%), valvular disease (6%) and miscellaneous (7%). Excellent correlation was obtained between "fast" MRI measurements and SM in MRI (SM vs BPMR interclass correlation coefficient ICC=0.965 and SM vs ALMR, ICC=0.958; P,0.05) with low interobserver variability (ICC=0.983 for SM; ICC=0.949 for BPMR; ICC=0.931 for ALMR). "Fast" measurements by MRI showed stadistical correlation between them (CCI=0.910) (Figure). Correlation between Echo and MRI measures was only moderate. (BPRM vs BPe CCI=0,469 mean difference-30 ml; ALMR vs MDDe ICC=0,456 mean difference-24 mL). Conclusions: 'fast' LAV measures by MRI are comparable with the MRI GS and also between them. Echo values seem to underestimate compared to MRI, so its use may not be suitable.
European Heart Journal - Cardiovascular Imaging, 2014
Clinical PETacquisitions of the heart suffer from artefacts and drops in image quality due to the... more Clinical PETacquisitions of the heart suffer from artefacts and drops in image quality due to the poor spatial resolution of the PET system. Moreover, cardiac PET images are further degraded by the blur caused by the breathing and beating motions, thus hampering diagnosis and evaluation of myocardial pathologies. Anatomy-enhanced PET reconstruction, using a high-resolution CT, has proven useful in brain imaging. In cardiac datasets however, due to the motion artefacts, the application of any restoring technique on datasets affected by motion blur needs to be preceded by the validation of the proposed method on realistic static datasets. In this work, the validation is performed using static cardiac ex vivo datasets obtained from a number of sacrificed sheep, scanned on a clinical PET/CTscanner. The aim of this work is to assess the effectiveness of reconstructions of the acquired datasets with different CTbased anatomical priors, in comparison to reconstructions currently applied in clinical practise. The gold standard to which all reconstructions are compared consists of images of the same hearts scanned on a small-animal PET scanner, whose high spatial resolution allows for almost artefact-free images. Encouraging results were obtained so far, with improvements in volume delineation and uniformity of activity values when anatomical information was used. Fig 1 shows the gold standard image (left) compared to a regular clinical reconstruction (middle) and to a reconstruction using the high-resolution CT as anatomical information (right).
Introduction: Transoesophageal echocardiography (TOE) has become routine during cardiac surgery f... more Introduction: Transoesophageal echocardiography (TOE) has become routine during cardiac surgery for evaluation of cardiac function and valve morphology prior and after repair of cardiac disease. Major complications of TOE are reported to be rare, especially in the hands of experienced investigators. However,a TOE probe might cause minor injuries in the stomach, especially if the procedure takes several hours. We therefore hypothesized that minor injuries are a common sequel of long-time TOE during cardiac surgery. Material and Methods: After induction of anesthesia in patients undergoing elective cardiac interventions, endoscopy of pharynx, esophagus and stomach was performed in order to exclude any previous lesion. A TOE probe was then inserted as part of the routine procedure and left in place until the operation was finished and the patient in stable condition to be transferred to the intensive care unit. The TOE probe was then removedand endoscopy was performed a second time to detect any new lesions in the stomach. All lesions of the mucosa were documented (type, localization, and number) as well the time needed for the TOE examinations before and after the cardiopulmonary bypass (CPB). Data are expressed as mean + standard deviation. Results: After approval of the Ethics committee and obtaining informed consent ten patients were included in our study. Duration of TOE probes in situ was 453 + 20 minutes. Of the ten patients included in the study only 1 patient had no lesion. In two patients only 1 lesion and in the others more than one could be detected. Five patients had 2 lesions and the last 2 patients had 3 and 4 lesions, respectively (1,9 + 1,1 lesions per patient). Most of the lesions were localized in the esophagus (10) and in the stomach (6); 2 lesions were detected in the pharynx and 1 lesion in the gastroesophageal junction. Most of the lesions were petechiae (9) and hematomas (6), while mucosal erosions and erythemas were present only two times. Severe lesions could not be detected. Conclusions: Our results have shown that minor injuries are caused frequently by TOE probes where the oesophageal and gastric mucosa are the most involved areas. A bigger sample size is needed to confirm if a longer duration the TOE probe in situ (more than 7 hours) is associated with more lesions. Furthermore, more lesions could also affect ICU and hospital length of stay.
European Heart Journal - Cardiovascular Imaging, 2013
Is there any association between systemic vascular reactivity and pulmonary artery pressure in pa... more Is there any association between systemic vascular reactivity and pulmonary artery pressure in patients with common forms of pulmonary hypertension?
This study aims to analyze the autonomic nervous system response during head-up tilt test (HUTT),... more This study aims to analyze the autonomic nervous system response during head-up tilt test (HUTT), by exploring the changes in dynamic properties of heart rate variability in subjects with and without syncopes, to predict the outcome of HUTT. Baroreflex response, as well as linear and non-linear parameters of RR-interval time series, have been extracted from the ECG of 66 subjects: 35 with and 31 without syncope during HUTT. The results show that, when considering the first 15 min of tilting position, the total power spectrum, the standard deviation, the long-term fractal scale of RR-interval and ΔRR-interval of time series increase, while the sample entropy decreases in the positive group compared to the negative one. These indices may be good predictors of positive response in patients with reflex syncope. Additionally, an analysis of the first 15 min of tilting position using kernel support vector machines leads to a correct classification of 85% of patients, within negative and p...
Cardiovascular remodelling in the conditioned athlete is frequently associated with physiological... more Cardiovascular remodelling in the conditioned athlete is frequently associated with physiological ECG changes. Abnormalities, however, may be detected which represent expression of an underlying heart disease that puts the athlete at risk of arrhythmic cardiac arrest during sports. It is mandatory that ECG changes resulting from intensive physical training are distinguished from abnormalities which reflect a potential cardiac pathology. The present article represents the consensus statement of an international panel of cardiologists and sports medical physicians with expertise in the fields of electrocardiography, imaging, inherited cardiovascular disease, cardiovascular pathology, and management of young competitive athletes. The document provides cardiologists and sports medical physicians with a modern approach to correct interpretation of 12-lead ECG in the athlete and emerging understanding of incomplete penetrance of inherited cardiovascular disease. When the ECG of an athlete is examined, the main objective is to distinguish between physiological patterns that should cause no alarm and those that require action and/or additional testing to exclude (or confirm) the suspicion of an underlying cardiovascular condition carrying the risk of sudden death during sports. The aim of the present position paper is to provide a framework for this distinction. For every ECG abnormality, the document focuses on the ensuing clinical work-up required for differential diagnosis and clinical assessment. When appropriate the referral options for risk stratification and cardiovascular management of the athlete are briefly addressed.
Niferidile (NF) is new Russian class III antiarrhythmic agent. Electrophysiological studies showe... more Niferidile (NF) is new Russian class III antiarrhythmic agent. Electrophysiological studies showed, that NF increased refractory periods much higher in atria than in ventricles, didn't influence parameters of sinus function, intra-, interatrial and AV-conductance. Aime: to study effects of NF 10, 20 and 30 mg/kg at main ECG characteristics (QT, QTc, QRS, ff and RR intervals) after conversion of persistent atrial fibrillation (AF) and flutter (AFL) to sinus rhythm (SR). Methods: 100 pts (64 male), age 58 + 12 years, with arrhythmia lasting 4,2 + 3,9 months (1 week-24 months) were included. 82 pts had AF and 18 AFL. Holter ECG recorder was activated 1 h before NF infusion. NF was administered as 3 i.v. bolus injections (10 mg/kg each) performed with the 15-min interval. If SR was restored within 15 min after injection, the next injection was cancelled. Successful conversion was defined as restoration of SR within 24 h after beginning of the treatment. Results: Cardioversion success rate of NF in dose of 10 mg/kg was 49%, in dose of 20 mg/kg it was 65%, and in dose of 30 mg/kg reached 88%. In 1 patient after infusion of 10 mg/kg of NF QT interval prolongated up to 700 ms and unsustained runs of polymorphyc ventricular tachycardia of 3-9 complexes were registrated during 15 min. This patient converted to normal SR in 22 h after NF infusion. Mean QT and QTc after NF infusion prolongated in dose-dependent manner. QT returned to normal meanings within 3 h in pts, who received 10 mg/kg and only within 22-23 h in pts, who received 20 or 30 mg/kg of NF. QTc interval in pts, who received 10 mg/kg reached normal value after 21 h and didn't return to normal meanings till the end of observation period in those who received 20 or 30 mg/kg. QT and QTc intervals in pts, who was given 20 or 30 mg/kg of NF, didn't differ significantly among themselves and exceeded appropriate meanings of those pts, who got 10 mg/kg of NF during all period of monitoring. NF caused increase of ff length, frequent transformation of AF to AFL, which typically preceded SR restoration. RR intervals after SR restoration didn't differ significantly between 3 groups of pts within 24 h. No effect was noted on the duration of the QRS interval in pts received different doses of NF. Conclusions: NF causes dose-dependent moderate prolongation of mean QT and QTc, doesn't influence RR and QRS intervals, regulates atrial activity and increases ff duration. I.v. NF in doses up to 30 mg/kg seems to be very effective in conversion of patients with persistent AF and AFL and proarrhythmic events are rare.
Background— Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studi... more Background— Ethnicity is an important determinant of cardiovascular adaptation in athletes. Studies in black male athletes reveal a higher prevalence of electric repolarization and left ventricular hypertrophy than observed in white males; these frequently overlap with those observed in cardiomyopathy and have important implications in the preparticipation cardiac screening era. There are no reports on cardiac adaptation in highly trained black females, who comprise an increasing population of elite competitors. Methods and Results— Between 2004 and 2009, 240 nationally ranked black female athletes (mean age 21±4.6 years old) underwent 12-lead ECG and 2-dimensional echocardiography. The results were compared with 200 white female athletes of similar age and size participating in similar sports. Black athletes demonstrated greater left ventricular wall thickness (9.2±1.2 versus 8.6±1.2 mm, P <0.001) and left ventricular mass (187.2±42 versus 172.3±42 g, P =0.008) than white athlet...
Regular participation in intensive physical exercise is associated with several structural and el... more Regular participation in intensive physical exercise is associated with several structural and electrophysiological cardiac adaptations that enhance diastolic filling and facilitate a sustained increase in the cardiac output that is fundamental to athletic excellence. Such cardiac adaptations are collectively referred to as the ' Athlete's Heart' and are frequently reflected on the 12-lead ECG and imaging studies. Thorough knowledge relating to exercise-associated cardiovascular adaptation is imperative for the purposes of differentiating physiological adaptation from cardiac pathology, since an erroneous diagnosis of cardiac disease has potentially serious consequences for the athlete's physical, psychological, social and financial well-being. The majority of studies investigating the cardiovascular adaptation to exercise are based on cohorts of Caucasian athletes. However, there is mounting evidence that ethnicity is an important determinant of the objective manifestations of cardiovascular adaptation to exercise. The most pronounced paradigm of ethnically distinct cardiovascular adaptation to exercise stems from athletes of African/ Afro-Caribbean descent, who exhibit a significantly higher prevalence of repolarisation anomalies and left ventricular hypertrophy, compared to Caucasian athletes; the differentiation between athlete's heart and hypertrophic cardiomyopathy is particularly challenging in this ethnic group. The extrapolation of ECG and echocardiographic criteria used to diagnose potentially serious cardiac disorders in Caucasian athletes to the African/Afro-Caribbean athlete population would result in an unacceptable number of unnecessary investigations and increased risk of false disqualification from competitive sport. Accurate interpretation of the athlete's ECG and echocardiogram is crucial, particularly when one considers the continuous expansion of preparticipation screening programmes. This review attempts to highlight ethnically determined differences in cardiovascular adaptation to exercise and provides a practical guide for the interpretation of baseline investigations in athletes of diverse ethnic backgrounds.
Background.-Heart failure (HF) with a preserved (P) left ventricular (LV) ejection fraction (EF) ... more Background.-Heart failure (HF) with a preserved (P) left ventricular (LV) ejection fraction (EF) is common, though its diagnosis and physiopathology remain unclear. We sought to compare the myocardial characteristics at rest and during submaximal exercise in patients with HFPEF and in controls. Methods.-Standardized submaximal exercise stress echocardiography was performed in (a) 36 patients from the KaRen HFPEF-registry, whose LV EF was ≥ 45%, and (b) 10 control patients free from manifestations of HF. Results.-During submaximal exercise LV-systolic function measured as global 4-chamber longitudinal strain was −17.2 ± 4.7% in patients with HFPEF versus −23.7 ± 3.1% in controls (P < 0.001), LV longitudinal diastolic function, expressed as e' was 9.9 ± 2.8 cm/s in patients, versus 14.5 ± 3 cm/s in controls (P < 0.001), and RV longitudinal systolic function, expressed as RVs', was 13.3 ± 3.5 cm/s in patients versus 17.7 ± 1.5 cm/s in controls (P < 0.05). LV afterload (arterial elastance was 2.6 ± 1 mmHg/ml in patients versus 0.8 ± 1.4 mmHg/ml in controls; P < 0.001) was significantly higher in the HFPEF than in the control group, and was correlated with a decrease in LV longitudinal strain (R = 0.63, P < 0.001) during exercise. Conclusion.-Significant abnormalities of LV-systolic and diastolic functions were revealed by exercise stress echocardiography in patients recently admitted for heart failure and with a preserved LVEF. These observations help clarifying persisting uncertainties regarding diastolic and systolic function in HFPEF and may help in selecting therapy for such patients.
The two air-stable m 2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluoro... more The two air-stable m 2-hydroxy-bridged binuclear hafnocene perfluorobutanesulfonate and perfluorobenzenesulfonate complexes were successfully synthesized. The high catalytic activity and recyclability of these complexes were exemplified for various carbon-carbon bond formation reactions. Compared with our previously reported hafnocene perfluorooctanesulfonate, these complexes show stronger Lewis acidity and better catalytic activity, and should find broad applications in organic synthesis.
≥ 4 segments). Among these patients, 19 (10.7%), had no significant coronary artery stenosis. Thi... more ≥ 4 segments). Among these patients, 19 (10.7%), had no significant coronary artery stenosis. This group included eight men (42%). Stress echo was performed during exercise in 17 patients and using dobutamine in 2. Peak systolic blood pressure was 193 ± 31 mmHg in these patients vs 193 ± 34 mmHg in patients with a large ischemic area (≥ 4 segments) but with significant coronary artery stenosis on angiography (ns). Conclusion.-The item ''false positive'' stress echo must be discussed since nearly 10% of patients with a large ischemic area during the test have non significant coronary artery lesion. In our study, these patients were more often women evaluated during exercise. Systolic blood pressure level does not explain the WMA observed during the test.
2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008
The aim of the present study was to evidence that the heart reinnervation can occur and it is rel... more The aim of the present study was to evidence that the heart reinnervation can occur and it is related with the time after transplantation (evolution with time). Data were evaluated using Multiple Correspondence Analyses (MCA), which is the ideal method to study the relation, probably nonlinear, between the Time After Transplantation (TAT) and the probable restoration of normal heart rate responses of sinus node regulated by the autonomic nervous system. Twenty four nonrejecting transplant recipients (60 +/- 48 months after transplantation) and nine healthy subjects were studied by heart rate variability parameters. Results showed that sympathetic activity is restored some time after transplantation. Until 48 months, the recent HTR are in direct correlation to low values SD and LF and for the oldest transplant recipient, these parameters are similar to that observed in normal subjects.
Sinus bradycardia and prolonged QT interval corrected (QTc) are frequently noted on resting ECG i... more Sinus bradycardia and prolonged QT interval corrected (QTc) are frequently noted on resting ECG in athletes. Possible explanation for longer QT includes inaccuracies in the correction formula. This study aimed to compare six formulas commonly used to correct QT interval duration by heart rate (HR): Bazett, Hodges, Fridericia, Framingham, linear and exponential regression. Population studied was of 1179 Caucasian people. QTc were calculated using the six formulas specified, as well as the correlation coefficients between QTc and HR. Additionally, QTc was determined for several thresholds of bradycardia (63bpm-43bpm). As expected, QTc is longer in women and in athletes (p<;10-4) for all correction formulas. QTc in bradycardia population were different from each formula: with Bazett formula, it is longer in non-bradycardia than in bradycardia group (404.10±24.6 ms vs. 384.70±24.37 ms, p<;10-4), with Fridericia formula, there was no difference between groups (394.12±24.60 ms vs. 394.71±23.89 ms, p N.S.), and with Hodges formula, it is longer in bradycardia group (393.35±22.78 ms vs. 400.35± 27.21 ms, p<;10-5). Finally, from our results, the best-adapted formula to overall thresholds of non-bradycardia is Fridericia one. Most of the correction formulas explored give an acceptable QTc approximation for a first screening in athletes. Further works should be addressed to the study of athlete's ventricular repolarization in a multifactorial way.
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