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Biomedical subjects

M M Massin

Publications and source records attributed to M M Massin.

At least 19 recordsLinked to original sources
PubMed2005

Patterns of physical activity determined by heart rate monitoring among diabetic children.

BACKGROUND: Children with type 1 diabetes should be encouraged to participate in physical activity because exercise can benefit insulin sensitivity and improve known risk factors for atherosclerosis. METHODS: Physical activity patterns of 127 children and adolescents with stable type 1 diabetes were investigated by 24 hour continuous heart rate monitoring. The percentage of heart rate reserve was used to measure the amounts of physical activity at different intensities. The results were compared with normative data. RESULTS: Diabetic preschoolchildren accumulated 192.7 (78.1), 39.1 (24.3), and 21.3 (9.4) minutes/day (mean (SD)) of light, moderate, and vigorous physical activity, respectively. At the same activity levels, diabetic schoolchildren accumulated 168.9 (76.7), 37.9 (15.9), and 19.0 (14.8) minutes/day, and diabetic teenagers accumulated 166.3 (67.5), 45.6 (26.9), and 25.2 (15.3) minutes/day. Diabetic schoolchildren were significantly more active than healthy peers when considering moderate activity; diabetic teenagers were significantly more active when considering moderate and vigorous activity. There was a negative correlation between the most recent glycated haemoglobin and the time spent in light activities in schoolchildren, and a negative correlation between mean glycated haemoglobin for one year and time spent in light and moderate activities in schoolchildren. CONCLUSION: The majority of our diabetic patients meet the classical paediatric guidelines for physical activity and compare favourably with their healthy peers.

Adolescent↗
PubMed2005

Recurrent syncope.

Explore the source record for details and available documents.

Adrenergic beta-Antagonists↗
PubMed2001

Normal ranges for the variability in heart rate in young infants while sleeping.

OBJECTIVE: Measurements of the variability in heart rate are increasingly used as markers of cardiac autonomic activity. We sought to establish the development this variability in healthy young infants while sleeping. PATIENTS: We carried out polygraphic studies with electrocardiographic recording in 587 healthy infants aged from 5 to 26 weeks. METHODS: We determined several variables over a period of 400 minutes sleeping: mean RR interval, 5 time-domain (SDNN, SDNNi, SDANNi, RMSSD, and pNN50) and 5 frequency-domain indexes (spectral power over 3 regions of interest, total power and low-to-high frequency ratio). Frequency-domain indexes were also assessed separately for the periods of quiet sleep and those of rapid eye movement sleep. RESULTS: Our data showed a significant correlation between the indexes of heart rate variability and the mean RR interval, the breathing rate, and the corrected age of the infants. We also demonstrated the importance of the maturation of the sleeping patterns. CONCLUSION: These data in a large cohort of healthy infants confirm a progressive maturation of the autonomic nervous system during sleep, and may be used to examine the influence of physiological and pathophysiological factors on autonomic control during polygraphic studies.

Age Factors↗
PubMed2001

The influence of fetal and postnatal growth on heart rate variability in young infants.

Heart rate variability (HRV), a measure of cardiac autonomic control, was analyzed in infants to assess the hypothesis that early undernutrition may induce autonomic dysfunction that could play a role in the programming of later cardiovascular disease. HRV data were collected during a night session in 546 healthy infants at 5-12 weeks of adjusted age, and statistical associations with fetal and postnatal growth indices were established. A significant positive correlation between birth weight, the ratio of neonatal weight to head circumference and postnatal weight gain, and HRV indices mostly influenced by sympathetic activity was demonstrated in 11- and 12-week-old infants. A slight correlation (p > 0.05) was also found in younger infants. These data suggest the influence of fetal and postnatal growth on the programming of the autonomic nervous system beyond the neonatal period. This influence may be one of the important mechanisms that link impaired growth in fetal and infant life to high blood pressure and other cardiovascular disease during childhood and adulthood (the Barker hypothesis).

Cardiovascular Diseases↗
PubMed2000

Circadian rhythm of heart rate and heart rate variability.

BACKGROUND: Measurements of heart rate variability (HRV) are increasingly used as markers of cardiac autonomic activity. AIM: To examine circadian variation in heart rate and HRV in children. SUBJECTS: A total of 57 healthy infants and children, aged 2 months to 15 years, underwent ambulatory 24 hour Holter recording. Monitoring was also performed on five teenagers with diabetes mellitus and subclinical vagal neuropathy in order to identify the origin of the circadian variation in HRV. METHODS: The following variables were determined hourly: mean RR interval, four time domain (SDNN, SDNNi, rMSSD, and pNN50) and four frequency domain indices (very low, low and high frequency indices, low to high frequency ratio). A chronobiological analysis was made by cosinor method for each variable. RESULTS: A significant circadian variation in heart rate and HRV was present from late infancy or early childhood, characterised by a rise during sleep, except for the low to high frequency ratio that increased during daytime. The appearance of these circadian rhythms was associated with sleep maturation. Time of peak variability did not depend on age. Circadian variation was normal in patients with diabetes mellitus. CONCLUSION: We have identified a circadian rhythm of heart rate and HRV in infants and children. Our data confirm a progressive maturation of the autonomic nervous system and support the hypothesis that the organisation of sleep, associated with sympathetic withdrawal, is responsible for these rhythms.

Adolescent↗
PubMed2000

Dependency of premature ventricular contractions on heart rate and circadian rhythms during childhood.

The aim of the present study was to identify and quantify the rate dependence of premature ventricular contractions (PVC) during childhood. A 24-hour Holter recording was performed in 16 consecutive children, aged 22 days to 11 years (mean age 5.6 years), with frequent (>5,000/day), isolated monomorphic PVC. Those PVC were identified and the length of the preceding sinus cycle was measured. The values were ordered into 50-ms class intervals, and the percentage of PVC for each class was calculated and then analyzed by linear regression analysis. On the basis of the significance of the p value, and the positive or negative value of the slope, we identified a tachycardia-enhanced, a bradycardia-enhanced, and an indifferent pattern. Chronobiologic analysis was made by the cosinor method. All the patients had upper and lower limits of cycle length beyond which PVC disappeared. A tachycardia-enhanced pattern was present in 7 patients and an indifferent one in 9 patients. In the latter a second-degree polynomial correlation was systematically found. Children but not infants had a significant circadian variation in the frequency of PVC with a very variable time of highest incidence. In conclusion, it is possible to identify a circadian rhythm of PVC and a spontaneous trend between their incidence and the length of the preceding cardiac cycle in children.

Child↗
PubMed2000

Heart rate variability and the outcome of head-up tilt in syncopal children.

OBJECTIVE: This study evaluated autonomic nervous system function in 5 young (6-10 years old) and 5 older (10-15 years) children with recurrent episodes of neurally mediated syncope and a positive tilt-test result, 10 with syncope but a negative test result and 30 age-matched healthy volunteers. METHODS: Time- (SDNN, SDNNi, SDANNi, rMSSD, pNN50) and frequency-domain indices (LF, HF, LF/HF) of heart rate variability (HRV) were measured during a 24-hour Holter recording and for 5 min. segments before and during 90 degrees head-up tilt (tests lasted 30 min. or until syncope occurred). RESULTS: 24-hour HRV-indices were within the normal range for all syncopal patients. Mean RR interval and HRV-indices, except LF/HF, were higher in the older children with a positive test result before they were tilted and during the first 5 min. of head-up tilt. HRV-indices tended to be lower after tilt in the younger children with a positive test result. SDNN and LF in older children with a positive test result and LF/HF in the younger ones increased during the 5 min preceding the syncope. No difference was observed between syncopal children with a negative test result and controls. CONCLUSION: This study confirms that patients with vasovagal syncope have no chronic differences from normal subjects in autonomic nervous system activity. The modulation of the autonomic tone during head-up tilt is abnormal in children who faint during the test, but younger and older patients respond differently to the orthostatic stimulus.

Adolescent↗
PubMed1999

Coarctation of the left pulmonary artery associated with congenitally corrected transposition.

We describe an infant with congenitally corrected transposition, ventricular septal defect and severe pulmonary stenosis. The heart occupied a midline position. Extension of ductal tissue had resulted in occlusion of the left pulmonary artery. As far as we are aware, this is the first report of an association of coarctation of the left pulmonary artery with corrected transposition.

Angiography↗
PubMed1999

Cardiac involvement in Coffin-Lowry syndrome.

Coffin-Lowry syndrome is an X-linked recessive syndrome of mental retardation, characteristic facies and skeletal anomalies. In one patient with the syndrome, we observed early recurrent episodes of congestive heart failure with intercurrent normalization and the late development of mitral insufficiency due to annular dilation and congenital abnormalities of the valve apparatus. This unusual course of cardiac involvement, the non-adaptation of the left ventricular contractility to the aggravation of the mitral insufficiency and the postoperative persistence of the ventricular dysfunction, underline the possible role of an associated primary myocardial disease. This clinical observation demonstrates clearly that a mitral valve malformation can occur in patients with the syndrome, but also the role of a dilated cardiomyopathy, which can be secondary to the mitral regurgitation, but is more likely a myocardial disorder occurring as part of the syndrome.

Abnormalities, Multiple↗
PubMed1999

Correlations between indices of heart rate variability in healthy children and children with congenital heart disease.

Heart rate variability, as determined from 24-hour Holter recordings, represents a noninvasive parameter for studying the autonomic control of the heart. It decreases with certain disease states characterized by autonomic dysfunction such as congestive heart failure. No study in healthy or cardiac children has been performed to determine the correlations between and within time and frequency domain indices of heart rate variability. We examined five time domain (SDNN, SDNNi, SDANNi, rMSSD and pNN50) and five frequency domain measures (ULF, VLF, LF, HF and balance LF/HF) in 200 healthy children and 200 children with congenital heart disease, aged 3 days to 14 years. All measures were significantly correlated with each other. However, the strength of correlation varied greatly. Our data show that variables strongly dependent on vagal tone (rMSSD, pNN50 and HF) were highly correlated (r value > 0.90), as well as SDNN and SDANNi. We conclude that certain time and frequency domain indices correlate so strongly with each other that they can act as surrogates for each other.

Adolescent↗
PubMed1999

Cardiac autonomic dysfunction in diabetic children.

OBJECTIVE: Adults with type 1 diabetes may have abnormal alterations in heart rate variability (HRV) due to cardiac autonomic neuropathy. This prospective study was performed to determine whether HRV can be used to detect subclinical autonomic neuropathy in diabetic children. RESEARCH DESIGN AND METHODS: We examined five time domain and three frequency domain HRV indices determined from 24-h Holter recordings in 73 diabetic children and adolescents aged 3-18 years (mean 12.1 years) with a mean duration of diabetes of 55 months. The measures were compared with normal ranges. Z scores were established for each parameter and were compared with classic risk factors of other diabetic complications. RESULTS: Most HRV indices were significantly depressed in children aged > or = 11 years, and the levels of HRV abnormalities were significantly correlated with long-term metabolic control (mean GHb for 4 years) in that age-group. In younger patients, HRV indices were within the normal range and were not correlated with the level of metabolic control. Illness duration and microalbuminuria but not short-term metabolic control (most recent GHb) were also independently predictive of HRV abnormalities. CONCLUSIONS: These results suggest that early puberty is a critical period for the development of diabetic cardiac autonomic dysfunction. Therefore, all type 1 diabetic patients should be screened for this complication by HRV analysis beginning at the first stage of puberty regardless of illness duration, microalbuminuria, and level of metabolic control.

Adolescent↗