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1.
Eur Ann Otorhinolaryngol Head Neck Dis ; 138(2): 116-117, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33004306
3.
Eur Ann Otorhinolaryngol Head Neck Dis ; 136(5): 379-383, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31202667

ABSTRACT

The goal is to clarify the epidemiology of hearing loss in patients with osteogenesis imperfecta (OI), so as to improve management. A literature review analyzed data from 15 patient series. Hearing loss prevalence in OI varied widely, from 2% to 94.1%. Typically, hearing loss was conductive in young patients and sensorineural in older patients. Prevalence increased with age, but after 50 years the increase was slight, and seldom became total. Hearing loss was usually bilateral, but not necessarily symmetrical. There were no correlations between type of mutation (COL1A1 or COL1A2), prevalence, type or severity of hearing loss, or age of symptom onset; there was intra-familial variability. There was also no correlation between mutated gene, type of mutation and auditory phenotype. Frequency, type and severity of hearing loss were unrelated to other clinical parameters. Hearing loss prevalence depended on type of OI: higher in type I and lower in type IV. Incidence of otitis media was higher in children with OI, related to the associated craniofacial dysmorphia. Hearing screening before 5 years of age with long-term follow-up are recommended.


Subject(s)
Hearing Loss, Conductive/etiology , Hearing Loss, Sensorineural/etiology , Osteogenesis Imperfecta/complications , Aging , Bone Demineralization, Pathologic/diagnostic imaging , Humans , Osteogenesis Imperfecta/classification , Temporal Bone/diagnostic imaging
4.
Eur Ann Otorhinolaryngol Head Neck Dis ; 136(2): 113-114, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30409749

ABSTRACT

INTRODUCTION: Patients with MERRF syndrome (Myoclonic Epilepsy with Ragged Red Fibres) usually present with encephalomyopathy. However, progressive, recurrent cervicothoracic lipomatosis may be rarely observed. CASE REPORT: The authors report 4 cases of MERRF syndrome associated with lipomatosis. In 3 patients, the diagnosis of MERRF syndrome was established on the basis of the clinical features of the lipomas and clinical interview revealing a personal or family history of lipomas and myopathy. DISCUSSION: In the presence of extensive spinal lipomatosis, the presence of other clinical signs of MERRF syndrome in the patient or the patient's family must be investigated. A diagnosis of MERRF syndrome can guide appropriate genetic counselling.


Subject(s)
Lipomatosis/etiology , MERRF Syndrome/complications , Adult , Female , Humans , Lipomatosis/diagnostic imaging , Lipomatosis/surgery , MERRF Syndrome/genetics , Male , Middle Aged , Neck , Siblings , Spinal Neoplasms/etiology , Spinal Neoplasms/surgery , Thorax
5.
Ann Cardiol Angeiol (Paris) ; 67(5): 352-360, 2018 Nov.
Article in French | MEDLINE | ID: mdl-30314667

ABSTRACT

The behavioral goals of the coronary patient require active management by the cardiologist. Every smoker must be clearly informed about the cardiovascular consequences of smoking and the major benefits of smoking cessation. The only advice to "quit smoking" is not enough. Validated "treatments" (cognitive-behavioral therapy, nicotine replacement therapy, varenicline, bupropion) must be used, with a precise strategy and prolonged follow-up. All drugs assistance can be prescribed in coronary patients and nicotine replacement therapy can even be used just after a myocardial infarction. Nutrition plays a significant role in cardiovascular prevention. Counseling today is based on solid evidence, although evidence is harder to obtain than with drugs. It should no longer be advisable only to "suppress cooked fats and starches" because these recommendations are unclear and/or false. Today we need positive food-based benchmarks and complex dietary patterns in which fruits and vegetables, fish, whole grains, pulses, nuts, olive oil and a diet closed to the Mediterranean diet. Dairy products have their place. Sugary foods should be limited especially in case of overweight and metabolic syndrome. Physical activity is part of good nutrition. Indeed, the fight against a very sedentary lifestyle and physical inactivity in coronary and heart failure patients is part of the lifelong treatment of these patients. The cardiologist and the general practitioner must be much more involved in their prescription and education to hope for good compliance.


Subject(s)
Cardiovascular Diseases/prevention & control , Diet , Exercise , Health Behavior , Smoking Cessation , Humans , Life Style , Secondary Prevention
6.
Scand J Med Sci Sports ; 28(10): 2144-2152, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29858514

ABSTRACT

The American Heart Association (AHA) recommendations for diagnosing peripheral artery disease (PAD) after exercise are a decrease >20% of ankle brachial index (ABI) or >30 mm Hg of ankle systolic blood pressure (ASBP) from resting values. We evaluated ABI and ASBP values during incremental maximal exercise in physically active and asymptomatic patients. Patients (n = 726) underwent incremental bicycle tests with pre- and post-exercise recording of all four limbs arterial pressures simultaneously. Univariate and multivariate analyses were performed to define the correlation between post-exercise ABI with various clinical factors, including age. Thereafter, the population was divided into groups of age: less than 40 (G < 40), from 40 to 44 (G40/44) from 45 to 49 (G45/49), from 50 to 54 (G50/54), from 55 to 59 (G55/59), from 60 to 64 (G60/64), and 65 and above (G ≥ 65) years. Results are mean ± SD. * is two-tailed P < .05 for ANOVA with Dunnett's post-hoc test from G40. Changes from rest in ASBP were -3 ± 22 (G < 40), -2 ± 20 (G40/44), 4 ± 22* (G45/49), 10 ± 25* (G50/54), 18 ± 21* (G55/59), 23 ± 27* (G60/64), and 16 ± 22* (G ≥ 65) mm Hg. Decreases from rest in ABI were 32 ± 9 (G < 40), 33 ± 9 (G40/44), 29 ± 8 (G45/49), 27 ± 10* (G50/54), 24 ± 7* (G55/59), 22 ± 12* (G60/64), and 21 ± 12* (G ≥ 65) % of resting ABI. Maximal incremental exercise results in ABI and ASBP changes are mostly dependent on age. The AHA limits for post-exercise ABI are inadequate following maximal incremental bicycle testing. Future studies detecting PAD in active patients should account for the effect of age.


Subject(s)
Ankle , Bicycling/physiology , Blood Pressure , Adult , Aged , Ankle Brachial Index , Exercise Test , Female , Humans , Male , Middle Aged , Prospective Studies
8.
Int J Sports Med ; 37(10): 792-8, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27286180

ABSTRACT

The aim of this study was to evaluate whether endurance athletes who exhibit deep bradycardia are more prone to arrhythmias and reflex syncope than their non-bradycardic peers. 46 healthy men (ages 19-35) were divided into 3 groups based on whether they were sedentary (SED,<2 h/week) or endurance trained (ET,>6 h/week), and non-bradycardic (NB, resting heart rate (HR)≥60 bpm) or bradycardic (B, resting HR<50 bpm). Resting HR was lower in ETB vs. ETNB and SED (43.8±3.1, 61.3±3.3, 66.1±5.9 bpm, respectively; p<0.001). Thus, 16 SED, 13 ETNB and 17 ETB underwent resting echocardiography, maximal exercise test, tilt test (TT) and 24 h-Holter ECG. Subjects were followed-up during 4.7±1.1 years for training, syncope and cardiac events. Our results showed that incidence of arrhythmias and hypotensive susceptibility did not differ between groups. During follow-up, no episode of syncope or near-syncope was reported. However, cardio-inhibitory syncope occurrence tended to be higher in ETB. Left ventricular end-diastolic diameter index was increased in ETB vs. ETNB and was correlated with resting HR (r=- 0.64; p<0.001). As a result, athletes with deep bradycardia do not present more arrhythmias and more hypotensive susceptibility than their non-bradycardic peers. Cardiac enlargement and autonomic alteration both seem to be involved in an athlete's bradycardia.


Subject(s)
Arrhythmias, Cardiac/epidemiology , Bradycardia/complications , Physical Endurance/physiology , Syncope/epidemiology , Adult , Athletes , Bradycardia/etiology , Electrocardiography, Ambulatory , Exercise Test , Follow-Up Studies , Heart Rate/physiology , Humans , Male , Prospective Studies , Sedentary Behavior , Young Adult
9.
Int J Sports Med ; 37(8): 625-32, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27116349

ABSTRACT

It is unknown whether commencing structured endurance training after 40 years of age is powerful enough to induce beneficial cardiovascular adaptations in later life. 34 men between the ages of 55 and 75 were included: 10 life-long sedentary seniors (SED), 13 endurance master athletes who commenced training≤30 years of age (ET30), and 11 endurance master athletes who commenced training≥40 years of age with no prior physical training (ET40). All performed resting 5-min spectral heart rate (HR) variability analysis, resting and submaximal-exercise echocardiography, and a maximal exercise test. Maximal oxygen uptake was higher and resting HR was lower in both trained groups vs. SED, without difference between ET30 and ET40. Atrial and left ventricle dimensions were greater in ET30 and ET40 vs. SED, without difference between both athletes groups. At rest, total arterial compliance was improved in both ET30 and ET40 compared to SED. During submaximal exercise, improvement in global LV afterload was only observed in ET30 vs. SED. Two powerful markers of health, maximal oxygen uptake and resting HR, did not differ between athletes who commenced training before 30 or after 40 years of age, but were significantly improved compared to their life-long sedentary counterparts.


Subject(s)
Adaptation, Physiological , Aging/physiology , Physical Conditioning, Human , Physical Endurance/physiology , Aged , Athletes , Cardiovascular Physiological Phenomena , Cardiovascular System , Echocardiography , Exercise Test , Heart Rate , Humans , Male , Middle Aged , Oxygen Consumption , Prospective Studies , Rest , Sedentary Behavior
10.
Scand J Med Sci Sports ; 26(4): 362-74, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26432052

ABSTRACT

Regular intensive exercise in athletes increases the relative risk of sudden cardiac death (SCD) compared with the relatively sedentary population. Most cases of SCD are due to silent cardiovascular diseases, and pre-participation screening of athletes at risk of SCD is thus of major importance. However, medical guidelines and recommendations differ widely between countries. In Italy, the National Health System recommends pre-participation screening for all competitive athletes including personal and family history, a physical examination, and a resting 12-lead electrocardiogram (ECG). In the United States, the American College of Cardiology and the American Heart Association recommend a pre-participation screening program limited to the use of specific questionnaires and a clinical examination. The value of a 12-lead ECG is debated based on issues surrounding cost-efficiency and feasibility. The aim of this review was to focus on (i) the incidence rate of cardiac diseases in relation to SCD; (ii) the value of conducting a questionnaire and a physical examination; (iii) the value of a 12-lead resting ECG; (iv) the importance of other cardiac evaluations in the prevention of SCD; and (v) the best practice for pre-participation screening.


Subject(s)
Athletes , Death, Sudden, Cardiac/prevention & control , Physical Examination , Sports Medicine/methods , Adolescent , Adult , Child , Electrocardiography , Exercise , Female , Heart Diseases/diagnosis , Heart Diseases/epidemiology , Humans , Incidence , Italy/epidemiology , Male , Surveys and Questionnaires , United States/epidemiology , Young Adult
11.
Eur J Prev Cardiol ; 23(6): 657-67, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26285770

ABSTRACT

There are large variations in the incidence, registration methods and reported causes of sudden cardiac arrest/sudden cardiac death (SCA/SCD) in competitive and recreational athletes. A crucial question is to which degree these variations are genuine or partly due to methodological incongruities. This paper discusses the uncertainties about available data and provides comprehensive suggestions for standard definitions and a guide for uniform registration parameters of SCA/SCD. The parameters include a definition of what constitutes an 'athlete', incidence calculations, enrolment of cases, the importance of gender, ethnicity and age of the athlete, as well as the type and level of sporting activity. A precise instruction for autopsy practice in the case of a SCD of athletes is given, including the role of molecular samples and evaluation of possible doping. Rational decisions about cardiac preparticipation screening and cardiac safety at sport facilities requires increased data quality concerning incidence, aetiology and management of SCA/SCD in sports. Uniform standard registration of SCA/SCD in athletes and leisure sportsmen would be a first step towards this goal.


Subject(s)
Cardiology/standards , Data Collection/standards , Death, Sudden, Cardiac/epidemiology , Registries/standards , Sports Medicine/standards , Sports/standards , Autopsy/standards , Cause of Death , Consensus , Doping in Sports , Humans , Incidence , Risk Factors , Substance Abuse Detection/standards , Terminology as Topic
12.
Physiol Meas ; 35(10): 2119-34, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25243636

ABSTRACT

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 positive response groups (specificity = 80.6% and sensitivity = 88.5%). In medical applications, it is important to avoid false negative diagnosis of syncopes during HUTT. Taking this into account, an overall accuracy of 72.1% can be obtained in the same window allowing the reduction of the examination time in the clinical domain.


Subject(s)
Support Vector Machine , Syncope/diagnosis , Tilt-Table Test , Adolescent , Adult , Autonomic Nervous System/physiopathology , Data Mining , Early Diagnosis , Electrocardiography , Humans , Male , Syncope/physiopathology , Young Adult
13.
Br J Sports Med ; 46 Suppl 1: i51-8, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23097480

ABSTRACT

Preparticipation screening programmes for underlying cardiac pathologies are now commonplace for many international sporting organisations. However, providing medical clearance for an asymptomatic athlete without a family history of sudden cardiac death (SCD) is especially challenging when the athlete demonstrates particularly abnormal repolarisation patterns, highly suggestive of an inherited cardiomyopathy or channelopathy. Deep T-wave inversions of ≥ 2 contiguous anterior or lateral leads (but not aVR, and III) are of major concern for sports cardiologists who advise referring team physicians, as these ECG alterations are a recognised manifestation of hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC). Subsequently, inverted T-waves may represent the first and only sign of an inherited heart muscle disease, in the absence of any other features and before structural changes in the heart can be detected. However, to date, there remains little evidence that deep T-wave inversions are always pathognomonic of either a cardiomyopathy or an ion channel disorder in an asymptomatic athlete following long-term follow-up. This paper aims to provide a systematic review of the prevalence of T-wave inversion in athletes and examine T-wave inversion and its relationship to structural heart disease, notably HCM and ARVC with a view to identify young athletes at risk of SCD during sport. Finally, the review proposes clinical management pathways (including genetic testing) for asymptomatic athletes demonstrating significant T-wave inversion with structurally normal hearts.


Subject(s)
Arrhythmogenic Right Ventricular Dysplasia/diagnosis , Athletes , Cardiomyopathy, Hypertrophic/diagnosis , Electrocardiography , Sports/physiology , Arrhythmogenic Right Ventricular Dysplasia/therapy , Cardiomyopathy, Hypertrophic/therapy , Critical Pathways , Death, Sudden, Cardiac/prevention & control , Early Diagnosis , Genetic Testing/methods , Humans , Physical Examination/methods , Prognosis , Risk Assessment/methods
14.
Br J Sports Med ; 46(5): 341-7, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21596717

ABSTRACT

OBJECTIVES: To evaluate the electrocardiographic (ECG) characteristics of West-Asian, black and Caucasian male athletes competing in Qatar using the 2010 recommendations for 12-lead ECG interpretation by the European Society of Cardiology (ESC). DESIGN: Cardiovascular screening with resting 12-lead ECG analysis of 1220 national level athletes (800 West-Asian, 300 black and 120 Caucasian) and 135 West-Asian controls was performed. RESULTS: Ten per cent of athletes presented with 'uncommon' ECG findings. Black African descent was an independent predictor of 'uncommon' ECG changes when compared with West-Asian and Caucasian athletes (p<0.001). Black athletes also demonstrated a significantly greater prevalence of lateral T-wave inversions than both West-Asian and Caucasian athletes (6.1% vs 1.6% and 0%, p<0.05). The rate of 'uncommon' ECG changes between West-Asian and Caucasian athletes was comparable (7.9% vs 5.8%, p>0.05). Seven athletes (0.6%) were identified with a disease associated with sudden death; this prevalence was two times higher in black athletes than in West-Asian athletes (1% vs 0.5%), and no cases were reported in Caucasian athletes and West-Asian controls. Eighteen West-Asian and black athletes were identified with repolarisation abnormalities suggestive of a cardiomyopathy, but ultimately, none were diagnosed with a cardiac disease. CONCLUSION: West-Asian and Caucasian athletes demonstrate comparable rates of ECG findings. Black African ethnicity is positively associated with increased frequencies of 'uncommon' ECG traits. Future work should examine the genetic mechanisms behind ECG and myocardial adaptations in athletes of diverse ethnicity, aiding in the clinical differentiation between physiological remodelling and potential cardiomyopathy or ion channel disorders.


Subject(s)
Athletes , Black People/ethnology , Electrocardiography , Heart Diseases/ethnology , White People/ethnology , Adolescent , Adult , Child , Death, Sudden, Cardiac/ethnology , Death, Sudden, Cardiac/prevention & control , Early Diagnosis , Heart Diseases/diagnosis , Humans , Male , Physical Examination , Prevalence , Qatar/epidemiology , Surveys and Questionnaires , Young Adult
15.
Ann Cardiol Angeiol (Paris) ; 59(6): 380-4, 2010 Dec.
Article in French | MEDLINE | ID: mdl-21055724

ABSTRACT

Cardiovascular benefits of regular physical activity are well described and validated. Coronary disease, both in primary and secondary prevention, is markedly concerned. Physical activity corrects most of the cardiovascular risk factors. Moreover, it has also a direct impact on the atherosclerosis progression. It seems that physical activity limits the chronic inflammatory state and oxidative stress level by its modulation on the PGC-1 alpha regulation. Unfortunately, despite this high level of proof, the physical activity prescription level is actually low.


Subject(s)
Coronary Artery Disease/prevention & control , Motor Activity , Humans
16.
J Cardiovasc Surg (Torino) ; 51(5): 669-81, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20924328

ABSTRACT

Understanding the relationship between acute type A aortic dissection and sport is crucial to prevent sudden cardiac death in seemingly healthy young individuals. Aerobic exercise produces only a modest rise in arterial blood pressure (140-160 mmHg) except at the highest levels of exertion, at which pressures between 180-220 mmHg are reached. Weight training, on the other hand, routinely produces acute rises in blood pressure to over 300 mmHg. This presents a danger for individuals with an unknown aortic aneurysm; the deteriorated mechanical properties of the aortic wall resulting from aneurysmal enlargement increase the susceptibility to aortic rupture when the high wall coincident with exertion exceeds the tensile strength of the aortic wall. Investigations by our group into the inciting events leading up to dissection have demonstrated a causal link between extreme exertion, severe emotional stress, and acute type A aortic dissection. Since aortic enlargement is often unknown to persons participating in weight training, especially in the youth population, a ìSnapShot Echocardiogramî screening program is been proposed; such a pilot program will raise awareness of the importance of pre-participation cardiac screening and allow for early detection of aneurysms as a means of preventing this ìsilent killerî from striking. As strong supporters of the numerous benefits of weight training, we encourage this activity in individuals without aneurysm; without aneurysm, wall tension does not reach dangerous levels, even at extremes of exertion. For individuals with known aortic dilatation, we recommend a program that limits their lifting to 50% of body weight in the bench press or equivalent level of perceived exertion for other specific strength exercises.


Subject(s)
Aortic Aneurysm/etiology , Aortic Dissection/etiology , Hemodynamics , Physical Exertion , Resistance Training/adverse effects , Weight Lifting/injuries , Acute Disease , Aortic Dissection/diagnosis , Aortic Dissection/physiopathology , Aortic Dissection/therapy , Aortic Aneurysm/diagnosis , Aortic Aneurysm/physiopathology , Aortic Aneurysm/therapy , Blood Pressure , Diagnostic Techniques, Cardiovascular , Early Diagnosis , Female , Heart Rate , Humans , Male , Predictive Value of Tests , Prognosis , Risk Assessment , Risk Factors , Young Adult
17.
Circulation ; 121(9): 1078-85, 2010 Mar 09.
Article in English | MEDLINE | ID: mdl-20176985

ABSTRACT

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 athletes. Eight black athletes (3%) exhibited a left ventricular wall thickness >11 mm (12 to 13 mm) compared with none of the white athletes. All athletes revealed normal indices of systolic and diastolic function. Black athletes exhibited a higher prevalence of T-wave inversions (14% versus 2%, P<0.001) and ST-segment elevation (11% versus 1%, P<0.001) than white athletes. Deep T-wave inversions (-0.2 mV) were observed only in black athletes and were confined to the anterior leads (V(1) through V(3)). CONCLUSIONS: Systematic physical exercise in black female athletes is associated with greater left ventricular hypertrophy and higher prevalence of repolarization changes than in white female athletes of similar age and size participating in identical sporting disciplines. However, a maximal left ventricular wall thickness >13 mm or deep T-wave inversions in the inferior and lateral leads are rare and warrant further investigation.


Subject(s)
Adaptation, Physiological , Athletes , Black People/statistics & numerical data , Electrocardiography , Exercise/physiology , Hypertrophy, Left Ventricular/ethnology , White People/statistics & numerical data , Adult , Africa/ethnology , Body Surface Area , Caribbean Region/ethnology , Exercise Test , Female , France/epidemiology , Heart Ventricles/diagnostic imaging , Humans , Hypertrophy, Left Ventricular/diagnostic imaging , Hypertrophy, Left Ventricular/physiopathology , Magnetic Resonance Imaging , Male , Mass Screening , Sex Factors , Ultrasonography , United Kingdom/epidemiology , Ventricular Function, Left
18.
Article in English | MEDLINE | ID: mdl-19163690

ABSTRACT

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.


Subject(s)
Biomedical Engineering/methods , Heart Transplantation/methods , Aged , Algorithms , Case-Control Studies , Cluster Analysis , Data Interpretation, Statistical , Heart Conduction System/physiopathology , Heart Rate/physiology , Humans , Male , Middle Aged , Models, Theoretical , Sympathetic Nervous System , Time Factors
19.
Br J Sports Med ; 42(3): 212-6; discussion 216, 2008 Mar.
Article in English | MEDLINE | ID: mdl-17768160

ABSTRACT

Data on tolerance of cardiac pacemakers during diving are very scarce. The aim of this study was to test electronic and mechanical tolerances of pacemakers exposed to experimental reproductions of pressures encountered during diving. Two samples each of 20 different models of cardiac pacemakers were exposed to compression during continuous telemetric monitoring. The first sample of each model was exposed to a pressure of 60 metres of sea water (msw). Each second sample was first exposed to a pressure of 30 msw then to 60 msw hyperbaric testing, with a period of 1 month between the two tests. Electronic function and structural integrity of the cans were evaluated. No electronic dysfunction was noted. We merely observed in some devices a transient increase of the pacing rate during pressurisation. No significant deformation of the can (< or =0.2 mm) was observed after the 30 msw hyperbaric test. However, after the 60 msw test, more than half of the devices tested were significantly and definitively deformed. These results show that tested pacemakers preserved a normal electronic function up to 60 msw but most of the tested devices demonstrated significant deformations of the pacemaker can for the hyperbaric exposure observed deeper than 30 msw. Without prejudging diving aptitude for implanted pacemaker patients, it therefore seems prudent to advise them against diving beyond 30 msw because of the potential for electronic dysfunction beyond that depth.


Subject(s)
Atmospheric Pressure , Diving/adverse effects , Pacemaker, Artificial/standards , Equipment Design , Equipment Failure , Humans
20.
Clin Exp Pharmacol Physiol ; 34(8): 796-8, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17600560

ABSTRACT

1. beta(3)-Adrenoceptors (AR) have been reported to be present in numerous species, where they mediate multiple responses. 2. The aim of the present study was to determine whether beta(3)-AR are present in intact rat heart and the functional implications of beta(3)-AR stimulation. The response to the cardiac beta(3)-AR-selective agonist BRL37344 was expressed as the percentage of values measured at baseline. 3. BRL37344 induced dose-dependent negative inotropic effects at concentrations ranging from 10(-11) to 10(-7) mol/L. BRL37344 (10(-8) mol/L) induced a decrease of left ventricular developed pressure (LVDP) from 127 +/- 5 to 89 +/- 16 mmHg (69 +/- 15%; P < 0.01) and +dP/dt from 2594 +/- 59 to 1885 +/- 50 mmHg/s (72 +/- 8%; P < 0.01). Moreover, a significant reduction of -dP/dt from 2176 +/- 42 to 1458 +/- 43 mmHg/s (67 +/- 8%; P < 0.01) was observed. The BRL37344 dose-response curves were not altered by nadolol (10(-5) mol/L), a potent beta(1)- and beta(2)-AR antagonist, but were completely suppressed by the addition of SR59230A (10(-5) mol/L), a potent beta(3)-AR antagonist. 4. The present study provides functional evidence for the presence of beta(3)-AR in rat hearts and shows, for the first time, that a highly specific beta(3)-AR antagonist can block the attenuation of LVDP caused by the specific beta(3)-AR agonist BRL37344 in rat beating hearts.


Subject(s)
Heart/physiology , Myocardium/metabolism , Receptors, Adrenergic, beta-3/drug effects , Receptors, Adrenergic, beta-3/metabolism , Ventricular Function, Left , Adrenergic beta-Agonists/pharmacology , Adrenergic beta-Antagonists/pharmacology , Animals , Dose-Response Relationship, Drug , Ethanolamines/pharmacology , Heart/drug effects , In Vitro Techniques , Male , Myocardial Contraction , Propanolamines/pharmacology , Rats , Rats, Wistar , Ventricular Function, Left/drug effects , Ventricular Pressure
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