Search PubMed⌕ Search

Biomedical subjects

D Pellerin

Publications and source records attributed to D Pellerin.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Heart failure and respiratory sleep disorders].

Chronic cardiac failure is often associated with sleep respiratory disorders. These abnormalities are often unrecognised and represent a marker of the severity of cardiac failure and carry a poor prognosis. The mechanism of apnoea is either central, resulting in periodic nocturnal Cheyne-Stokes respiration, or peripheral by obstruction of the upper respiratory tract. Both mechanisms may be observed in the same patient. Oxygen desaturation, fragmentation of sleep and inspiratory depression lead to sympathetic activation and an increase in let ventricular afterload which can aggravate the cardiac failure. Treatment by continuous positive pressure with a nasal mask can help some patients. It is therefore important to diagnoses these nocturnal disorders using simplified polysomnographic recordings.

Cheyne-Stokes Respiration↗
PubMed2001

[Ambulatory surgery].

Explore the source record for details and available documents.

Ambulatory Surgical Procedures↗
PubMed2001

Autonomic influences on ventricular repolarization in congestive heart failure.

We studied the QT interval rate-dependence in patients with congestive heart failure (CHF). The long-term autonomic nervous function was investigated by separate analysis of diurnal and nocturnal periods. For this purpose, QTm rate-dependence was determined from Holter recordings. Twelve patients with stable CHF (mean age 63 +/- 2 years) and 15 healthy subjects (mean age 59 +/- 4 years) were included in the study. CHF patients showed an increased nocturnal QTm rate-dependence when compared to normal subjects (0.150 [95% confidence interval (CI) 0.114 to 0.186] versus 0.106 [95% CI 0.080 to 0.133], P < .05). In contrast, QTm rate-dependence was not significantly different between the 2 groups during the day (0.177 [95% CI 0.149 to 0.210] in the CHF group versus 0.194 [95% CI 0.158 to 0.231] in the control group). It was also not significantly different between day and night for the CHF group, thus showing a loss of the circadian modulation in these patients. Thus, ventricular myocardial properties are altered by changes in the autonomic nervous system in CHF, as observed at the atrial level. These modifications may be related to the increased susceptibility to ventricular arrhythmias.

Aged↗
PubMed2000

[Heart failure and sleep respiratory disorders. Prevalence, physiopathology and treatment].

Cheyne-Stokes respiration occurs during sleep in 40-45% of patients with NYHA class III and IV heart failure. Such patients experience repeated episodes of progressively diminishing ventilation associated with desaturation followed by periods of increasing-amplitude ventilation. The mechanism appears to be related to hyperventilation leading to hypocapnia which occurs near a critical threshold of apnea during sleep stages I and stage II and interrupts central ventilatory control. The total duration of the periodic respiration cycle would depend on the increased circulation time subsequent to lowered cardiac output. Brief periods of waking provoked by Cheyne-Stokes respiration, accentuating sympathetic nervous system activity, are an unfavorable prognostic factor in heart failure. Activation of the sympathetic system may be corrected by CPAP although the long-term effect on heart failure remains controversial. Other treatments, such as oxygen therapy or theophylline, combined with optimized treatment of heart failure, have been proposed.

Cardiac Output↗
PubMed2000

[Aged parents and aging handicapped persons: a new situation, an attempt to respond].

The longevity increase which characterises the society evolution at the end of the 20th century, also concerns the handicapped people. The fact is particularly outstanding for mentally handicapped people such as the Down's Syndrome population. We are nowadays discovering the first generation of the "over 40 year-old people". Among the eldest, many of them have never left home as specialised structures were non existent when they were young. Even those, not many of them in that age group, who have been able to have access to a CAT and to profit by a specialised centre, cannot carry on working after their 35th birthday, because of their early ageing, and because of their tiredness. Therefore, they are early excluded from the CAT, they lose their advantage of being in a specialised centre and they finely have to go back home. Many parents of mentally handicapped people who live at home, even though they are not yet too old, seem to get more and more tired with their ageing advance, which, day after day, makes their unremitting action harder and harder towards their child who is also getting older. The makers relate the innovating and experimental initiative of a "Hameau Services", nowadays located at Sommières-du-Clain, a rural parish in the south of Vienne country, which offers to welcome still valid ageing parents and their mentally handicapped ageing child who lives in their own house. The collective services which are assured by the managing association, tend to relieve them in their daily material tasks in the aim of contributing to the prejudice of the unexpected arrival of the manifestations of the subordination through a proposition of a better life quality of the handicapped adult and his parents.

Aged↗
PubMed1999

Comparison of 2 myocardial velocity gradient assessment methods during dobutamine infusion with Doppler myocardial imaging.

Myocardial velocity gradient (MVG) has been shown to be the best quantitative parameter for the detection of ischemic myocardium during dobutamine infusion with the use of Doppler myocardial imaging. MVG has been previously assessed by velocity measurements across the thickness of the myocardium at the time of visually selected maximal color brightness (thickness-velocity plot method). We hypothesized that MVG could be assessed by velocity measurements throughout the cardiac cycle in the subendocardium parallel to the endocardial boundary to the left ventricular cavity and in the subepicardium parallel to the epicardial boundary (time-velocity plot method). This study was designed to compare MVG obtained from the thickness-velocity plot method and from the time-velocity plot method in quantifying dobutamine-induced changes in myocardial wall motion in 8 phases of the cardiac cycle on color M-mode Doppler myocardial imaging recordings of the left ventricular posterior wall performed in 8 conscious dogs at baseline and at steady state during dobutamine infusion (10 microg/kg per minute). For both methods, MVG was considered present if its mean value was significantly different from zero and if endocardial and epicardial velocities were significantly different. There was close agreement between the 2 methods. MVG was present during the preejection period, systole, rapid ventricular filling, and atrial contraction. Dobutamine induced a significant increase in MVG during the preejection period (from 2.64 +/- 0.83 to 4.05 +/- 0.81 seconds-1 ), systole (from 2.14 +/- 0.59 to 6.08 +/- 2.20 seconds-1 in early systole, from 1.90 +/- 1.06 to 5.31 +/- 2.95 seconds-1 in mid systole, from 1.37 +/- 0.57 to 2.44 +/- 0.53 seconds-1 in end systole), and rapid ventricular filling (from 3.06 +/- 1.12 to 7.82 +/- 2.58 seconds-1 ), related to a greater rise in endocardial than in epicardial velocities. The time-velocity plot method showed that ejection and diastole were 11% and 28% decreased during dobutamine infusion, respectively, as heart rate was 31% increased. Thus according to our quantitative criteria, both MVG assessment procedures enabled objective interpretation of dobutamine effects on left ventricular wall motion. In addition, the time-velocity plot method provided automatic detection of peak velocity, timing, and duration of wall velocity changes over time.

Animals↗
PubMed1999

Concordance between dobutamine Doppler tissue imaging echocardiography and rest reinjection thallium-201 tomography in dysfunctional hypoperfused myocardium.

OBJECTIVE: To evaluate the efficiency of the new technique colour Doppler tissue imaging (DTI) by studying the concordance between dobutamine DTI, standard grey scale echocardiography (SE), and rest-reinjection TI-201 tomography (TI) in dysfunctional myocardium. PATIENTS: 23 patients with chronic wall motion abnormalities and proven coronary artery disease (> 70% diameter stenosis of at least one major coronary artery at angiogram). METHODS: The contractile reserve and the resting perfusion characteristics of dysfunctional myocardial segments were assessed with low dose dobutamine SE and/or DTI (2.5 up to 20 gamma/kg/min) and TI on a semiquantitative basis. The DTI or SE data were separately compared with TI, on the basis of a 13 segment ventricular model. The resulting score of combined DTI and SE was also compared with TI. Finally the results obtained from DTI were compared with SE. RESULTS: A total of 142 severely hypokinetic or akinetic segments were visualised. The viability study was feasible in 127 (89%) and 121 (85%) segments with DTI and SE, respectively. TI detected viability more frequently than DTI (84 v 61, p < 0.001) and SE (80 v 50, p < 0.001). However, as many viable segments were detected with combined DTI and SE as with TI (78 v 84, NS). The kappa values between TI and SE, DTI or combined SE and DTI were 0.38, 0.45, and 0.57, respectively, and increased to 0.52 and 0.76, respectively, for SE and DTI versus TI when mid-anterior and mid-inferior segments only were considered. The kappa value between SE and DTI was 0.34. CONCLUSIONS: DTI is a helpful adjunct to SE, when using low dose dobutamine. This combination revealed as many viable segments as TI and showed a better agreement than DTI or SE alone for the assessment of myocardial viable segments evidenced by TI.

Adrenergic beta-Agonists↗
PubMed1999

[Sleep-related cardiac insufficiency and respiratory disorders. Prevalence, physiopathology, and treatment].

Cheyne-Stokes respiration occurs during sleep in 40-45% of patients with NYHA class III and IV heart failure. Such patients experience repeated episodes of progressively diminishing ventilation associated with desaturation followed by periods of increasing-amplitude ventilation. The mechanism appears to be related to hyperventilation leading to hypocapnia which occurs near a critical threshold of apnea during sleep stages I and stage II and interrupts central ventilatory control. The total duration of the periodic respiration cycle would depend on the increased circulation time subsequent to lowered cardiac output. Brief periods of waking provoked by Cheyne-Stokes respiration, accentuating sympathetic nervous system activity, are an unfavorable prognostic factor in heart failure. Activation of the sympathetic system may be corrected by CPAP although the long-term effect on heart failure remains controversial. Other treatments, such as oxygen therapy or theophylline, combined with optimized treatment of heart failure, have been proposed.

Adolescent↗
PubMed1998

[Patient education by the surgeon. Judicial aspects, ethical aspects, deontologic aspects].

AIM OF THE STUDY: The surgeon must inform his patient about eventual risks before any investigation with diagnosis purpose and before any therapeutic intervention. According to the decree of the first Civil chamber of the "Court of Cassation", the surgeon must be able to prove that this information has been given as required by the article 1315 of the civil code. This decree has created in France an important change in the relationship between surgeon and patient. The French Academy of Surgery has organized a special session to study this problem in terms of legal, ethical and deontological aspects. CONCLUSIONS OF THE ACADEMY: The Academy confirms the necessity to give information to the patients and suggests that the modalities of the information be prepared by the medical societies, the "Conseil National de l'Ordre des Médecins", eventually by ethical committees and legal organizations concerned with medical questions, in view of a common use in all French juridictions. According to the Academy, it is necessary to determine the limits of the information to be given to the patient concerning the most common risks and those with the most serious consequences, in order not to disturb him psychologically. The Academy wishes that necessary and sufficient means be indicated in order for the surgeon to be able to prove that the information has really been given.

Ethics, Medical↗
PubMed1998

Pre-ejectional left ventricular wall motions studied on conscious dogs using Doppler myocardial imaging: relationships with indices of left ventricular function.

Duration of the pre-ejection period is a sensitive index of myocardial function. Our purpose was to document normal pre-ejectional left ventricular (LV) wall motions at rest and under dobutamine using Doppler myocardial imaging (DMI), and to correlate posterior wall velocities with indices of LV systolic function. M-mode recordings of both walls were imaged on eight conscious dogs chronically instrumented. Subendocardial pre-ejectional velocities were digitized and measured every 3.8 ms. DMI analysis consisted of sign recognition, velocity measurement, duration and timing from the Q wave of the electrocardiogram. Isovolumic contraction time (Ict) was represented by the time interval from onset to peak of the first derivative of LV pressure. Conventional Doppler labelling of velocity signs, positive toward and negative away from the transducer, was applied to the direction of encoded wall motions. For physiological understanding, wall motions of both walls were also labelled inward and outward with respect to the left ventricular cavity center. In each wall, PEP was shown as several colored strips, each strip representing the period of time that the wall was moving in one direction. Changes in velocity sign corresponding to changes in direction of motion were opposed in each wall (p < 0.001), featuring successive inward and outward wall motions. There was a markedly sustained inward motion during Ict. Its velocity amplitude increased with dobutamine. There was a positive correlation between velocities of the inward motion contemporaneous of Ict and ejection fraction (r = 0.72, p < 0.003). Values of Ict respectively drawn from DMI and from hemodynamics were also significantly correlated (r = 0.85, p < 0.007). Thus, the inward motion evidenced by DMI during Ict appears promising to assess myocardial function and effect of drugs.

Animals↗
PubMed1998

Effects of a selective A1-adenosine receptor agonist on heart rate and heart rate variability during permanent atrial fibrillation.

BACKGROUND: Mean heart rate and irregularity of the rate, i.e., heart rate variability (HRV), are two aspects of heart rate during atrial fibrillation (AF). An important goal of AF therapy is to control mean heart rate during exercise; the determinants of HRV during AF remain poorly known although its prognostic value has been established. OBJECTIVES: To investigate the effects of a stable, long-acting, selective A1-adenosine receptor agonist, SDZ WAG994, on heart rate during exercise and on HRV. METHODS: In a multicenter, double-blind, randomized, placebo-controlled, parallel group study, patients with permanent AF performed a symptom-limited exercise test and underwent 24-hour ECG monitoring on day 1 during treatment with placebo, and on day 2 during treatment with either placebo or 2 mg SDZWAG994 orally. Changes in mean heart rate during exercise and changes in HRV indices between day 1 and day 2 were compared between the two groups. RESULTS: Thirty-two patients (64 +/- 8 years; 81% male; 25% in NYHA Class II; 38% with no structural heart disease) were included in the study. During active treatments, heart rate remained unchanged at rest and increased significantly during exercise. A significant daytime increase in short-term HRV indices (DpNN50 = 4.5% P = 0.01; DrMSSD = 6% P = 0.03; DSDNN Index = 6% P = 0.02) occurred during active treatment. CONCLUSIONS: Selective A1-adenosine receptor agonism with SDZ/WAG994 limits the increase in mean heart rate during exercise in patients with AF. In addition, this agonist selectively increases short-term HRV indices, suggesting that pNN50, rMSSD, and SDNN reflect vagal influences during AF.

Adenosine↗
PubMed1998

[Doppler tissue imaging of pre-ejection left ventricular wall dynamics in normal subjects].

Pre-ejectional left ventricular wall motion has been demonstrated clinically by angiography. Intramyocardial wall velocities generated by cardiac contraction may be measured by Doppler tissue imaging. The aim of this study was to detect pre-ejectional wall motion and to analyse its sequencer. A long axis M Mode with simultaneous septal and posterior wall imaging was performed in 11 normal subjects (age 37 +/- 15 years) with velocity analysis between the electrocardiographic Q wave and the onset of ejection by digitised analysis between the electrocardiographic Q wave and the onset of ejection by digitised images with automatic velocity extraction (3.8 ms) along a horizontal subendocardial line. The total duration of the pre-ejectional periods in conventional and Doppler tissue imaging are compared. Oscillatory velocimetric appearances with alternate colours of adjacent bands in each wall and a mirror image between walls was observed. The mean and peak velocities of the first four bands were significantly different between the walls (p < 0.001) as were the absolute values between bands 2 (p < 0.02) and 3 (p < 0.006). The duration of band 2, related to motion mainly towards the center of the ventricular chamber exceeded that of the adjacent bands (septum p < 0.02, posterior wall p < 0.001). The correlation coefficient for total duration of the pre-ejectional period between Doppler tissue imaging and conventional Doppler was 0.83, p < 0.05 for the interventricular septum and 0.76, p < 0.04 for the posterior was. The authors conclude that regional pre-ejectional wall motion can be recorded. During isovolumic contraction, there is motion predominantly towards the center of the left ventricular chamber of the two walls, confirming previous angiographic findings. Its timing suggests that wall motion proceeds the increase in ventricular pressure.

Adult↗
PubMed1998

[The echocardiographic examination in adult cardiomyopathy].

Echocardiography allows distinction between the diastolic dysfunction of hypertrophic or restrictive cardiomyopathies and the systolic dysfunction of dilated cardiomyopathy. The diagnosis and prognosis may be deduced from echocardiographic parameters. In hypertrophic cardiomyopathy systolic function is normal and there is asymmetric left ventricular hypertrophy (> 13 mm) associated with a reduced diastolic dimension and atrial dilatation resulting from diastolic dysfunction. The prognosis could be related to the severity of left ventricular hypertrophy; right ventricular hypertrophy is uncommon and its severity seems to be related to that of left ventricular hypertrophy. Restrictive cardiomyopathies are less common and amyloidosis is the commonest cause. Symmetric hypertrophy with reduced diastolic dimensions is observed; right ventricular involvement occurs in about 30% of cases. The prognosis seems to be related to the degree of parietal infiltration and, at advanced stages, systolic function is abnormal (fractional shortening < 20% with a left ventricular diastolic dimension > or = 55 mm) and rapidly fatal. Dilated cardiomyopathy is diagnosed when wall thickness is normal but left ventricular diastolic dimensions > 27 mm/m2 and ejection fraction < 45%. Right and left ventricular dimensions of the same size, left ventricular diastolic dimensions > 70 mm and left ventricular ejection fractions < 20% are poor prognostic indicators.

Adult↗
PubMed1998

[Contribution of doppler echocardiography in the evaluation of ventricular filling in cardiac insufficiency and estimation of filling pressures].

The study of diastolic function is an essential step in Doppler echocardiographic investigation of cardiac failure. Although the recording of transmitral flow remains the basis of analysis of diastolic function, it should be completed by other Doppler parameters. In fact, the simple analysis of transmitral flow is not sufficient because of the interplay of other factors, especially the preload. The authors describe the complementary ultrasonographic approaches for analysis of diastolic function, especially the ventricular filling pressures, by recording of pulmonary venous flow, the kinetics of the mitral annulus and the propagation of intra-ventricular flow.

Cardiac Output, Low↗