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Biomedical subjects

A Davignon

Publications and source records attributed to A Davignon.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Treatment of congenital pulmonary valve stenosis by percutaneous valvuloplasty].

The purpose of this study was to evaluate the efficacy technique and follow-up results of balloon valvuloplasty for congenital valvular pulmonary stenosis. Percutaneous dilatation was performed in 48 patients aged 0.5 to 21 years (m = 7.5 yrs) from two pediatric cardiology centers (Lyon and Montreal). The right ventricular peak systolic pressure ranged from 42 to 180 mmHg (m = 93) before dilatation and fell from 24 to 105 mmHg (m = 48) immediately after dilatation. The pulmonary valvular peak systolic pressure gradient ranged from 22 to 156 mmHg (m = 73) and fell to 4 to 70 mmHg (m = 27) after the procedure (P less than 0.001). Follow-up continuous doppler data was available from 33 patients at 1 to 37 months (m = 9.2 months) after dilatation. The maximal instantaneous gradient from right ventricle pulmonary artery ranged from 0 to 74 mmHg (m = 27).

Adolescent↗
PubMed1991

[Results of the surgical treatment of critical aortic valve stenosis in the newborn infant].

Retrospective studies have been conducted in Lyon (33 patients) and Montreal (24 patients) in order to compare the results of transventricular valvotomy (TVV, 20 cases) and aortic valvotomy with cardiopulmonary bypass (CPB, 37 cases) in neonatal critical aortic stenosis. Clinical, echocardiographic, catheterization and operative data were analyzed in order to determine prognostic factors. Mortality rate was 59%: 30/34 perioperative deaths in the first month, and 4 late deaths after a reintervention for severe residual obstruction. Long term follow up was available for 23 patients (41%) for a 2 to 16 year period (mean 7.5). Five patients (7%) required a reintervention six years after the initial operation. Two of them required valve replacement. Eighteen patients (31%) surviving the initial operation, displayed a satisfactory result, being free of symptoms, endocarditis, reoperation and sudden death. Factors that influenced the outcome included severe heart failure, a left ventricular end-diastolic diameter below 14 mm, an aortic valve annulus below 8 mm, and a poor shortening fraction. Factors that did not influence the prognosis were age, pulmonary hypertension, and the anatomic type of the valve. Trans-aortic valvotomy with CPB was associated with a smaller operative mortality and a better long term result than TVV.

Aortic Valve↗
PubMed1990

Frequency and prognosis of arrhythmias after operative "correction" of tetralogy of Fallot.

Two hundred twenty-four consecutive patients operated on for tetralogy of Fallot were followed from 1 to 28 years (mean 11). Mean age at surgery was 5.3 years (range 1 to 14). Postoperative right ventricular systolic pressure was 60 mm Hg in 19 of 213 patients (9%). Fourteen patients (6%) had ventricular premature complexes on surface electrocardiograms. Seventy-nine patients underwent treadmill exercise tests, and ventricular premature complexes were induced in 17 (22%). Twenty-four-hour ambulatory monitoring in 92 patients demonstrated significant ventricular arrhythmias (greater than or equal to grade 2 of the Lown classification) in 41 (45%). The frequency of ventricular arrhythmias correlated with length of follow-up and duration of cardiopulmonary bypass. No correlation was found with age at surgery, postoperative right ventricular systolic pressure and importance of conduction defects on electrocardiogram. There were no sudden or unexpected deaths during follow-up.

Adolescent↗
PubMed1990

Successful treatment of chaotic atrial tachycardia with oral flecainide.

Two infants with chaotic atrial tachycardia diagnosed at birth and at 11 weeks of life, were treated successfully with oral flecainide. Both patients were in heart failure at initiation of therapy. Six months and 17 months later, respectively, they have had no recurrence of chaotic atrial tachycardia, left ventricular function returned to normal and therapy was stopped in both.

Administration, Oral↗
PubMed1990

Ventricular arrhythmias after correction of ventricular septal defects: importance of surgical approach.

To compare the prevalence of conduction disturbances and ventricular arrhythmias in cases of postoperative ventricular septal defect, 100 patients (50 with repair by right atriotomy, group 1; and 50 with repair by right ventriculotomy, group 2) underwent complete evaluation including an electrocardiogram (ECG) and 24 h ambulatory ECG monitoring. The two groups were comparable except for a shorter follow-up duration (7 +/- 3 versus 12.4 +/- 7 years) and a younger age at evaluation (12.4 +/- 5 versus 16.9 +/- 7 years) in group 1. Complete right bundle branch block was less frequent in group 1 than in group 2 (20% versus 50%, p less than 0.05) but three of the four patients with complete atrioventricular (AV) block detected on ambulatory monitoring were in group 1. Six patients had significant supraventricular arrhythmias, all well tolerated. Ambulatory monitoring revealed significant ventricular arrhythmias (modified Lown grade 2 or higher) in 39 patients, with a lower prevalence in group 1 (30% versus 48%, p = 0.05). No correlation was found between prevalence of ventricular arrhythmias and right ventricular systolic pressure, cardiopulmonary bypass duration, presence of a synthetic patch, previous pulmonary artery banding, presence of complete right bundle branch block and cardiomegaly on chest X-ray film. Prevalence of ventricular arrhythmias increased with follow-up duration, age at evaluation and age at surgery. These were always well tolerated and did not warrant treatment. Thus, right atriotomy reduces the prevalence of right bundle branch block but does not prevent late AV block. Ventricular arrhythmias are frequent after surgical closure of ventricular septal defect whatever the surgical approach and their prevalence is not statistically different from that in postoperative tetralogy of Fallot.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Longitudinal study of various transport abnormalities as an index of severity in children and adolescents suffering from essential hypertension.

Erythrocyte cation fluxes were measured in fresh cells, on two different occasions, in 90 children and adolescents suffering from essential hypertension who were followed for a prolonged period. The purpose of the present study was to track the stability of erythrocyte cation fluxes with time, and to determine whether a known sodium transport abnormality can predict the severity of essential hypertension. The patients with an increased Na-Li countertransport were the most severely hypertensive in three different ways. Clinically, they presented a stable rather than a labile form of hypertension. Hemodynamically, the mean arterial pressure was higher than that of the other subgroups. Finally, in those children followed for more than 2 years, this subgroup remained hypertensive with time. The patients with a decreased Na,K cotransport activity were second in severity; however, blood pressure was often labile, mean arterial pressure was slightly lower than that of the previous subgroup and all patients remained hypertensive with time but in four out of six patients the hypertension was labile. The patients with increased passive sodium permeability presented a mild form of hypertension. The patients with normal erythrocyte cation fluxes seemed to form a heterogeneous group. A few were severely hypertensive, but in most the hypertension was borderline and transient. We conclude that determination of erythrocyte cation fluxes may be reproducible, and may be a useful index of the severity of essential hypertension in children and adolescents.

Adolescent↗
PubMed1990

[Characteristics of paroxysmal atrial tachycardia in infants according to the age of onset].

Seventy consecutive patients hospitalized before 1 year of age for reentrant paroxysmal atrial tachycardia (PAT) were studied according to the age of onset of arrhythmia making 3 distinctive groups: group I: 10 patients in whom onset of the arrhythmia occurred during foetal life; group II: 39 infants whose arrhythmia appeared during the first month of life and group III consisting of 21 patients in whom tachycardia began between 1 and 12 months of age. The characteristics and the consequences of the arrhythmia as well as the patients' course and the different treatments used were analysed. Foetal tachycardias were characterized by a slower heart rate. Episodes were most often short and repetitive as opposed to post-natal tachycardias which were often prolonged but somewhat unfrequent. Before the age of 3 months the occurrence of heart failure was more frequent. Independently of the age of onset, 43% of patients presented Wolff-Parkinson-White syndrome (WPW), which disappeared spontaneously in 1 out of 3 cases. The existence of WPW syndrome was correlated with late relapses.

Age Factors↗
PubMed1990

The evolving pattern of pediatric endocarditis from 1960 to 1985.

A diagnosis of endocarditis was made in 37 patients (three days to 21 years old) on the basis of the following: histology in 11; at least two positive blood cultures in patients with underlying cardiac disease in 22; less than two positive blood cultures, vegetations seen at echocardiography and a suggestive clinical syndrome in four. Twenty-six patients had primary endocarditis (17 with pre-existing cardiopathy, nine with normal hearts). The 11 others developed secondary endocarditis following heart surgery (early onset in six, late onset in five). The mean delay before diagnosis was prolonged 35.8 days. The clinical and laboratory findings included weakness in 36 patients, fever in 35, new or modified heart murmur in 14, positive blood cultures in 30, anemia in 12, high white blood cell count in 15, increased sedimentation rate in 14, and positive echocardiogram in 11. Etiologic agents isolated were: streptococci in 17, staphylococci in seven, miscellaneous germs in eight, and aspergillus in two. Mortality was greater in patients less than one year old, infected with aspergillus or without underlying heart disease. The present study suggests that childhood endocarditis remains uncommon but presents a poor prognosis with a mortality of 27% and a morbidity of 85.7%.

Adolescent↗
PubMed1990

Postoperative evaluation after end-to-end subclavian-left coronary artery anastomosis in anomalous left coronary artery.

In most instances of anomalous left coronary artery originating from the pulmonary artery, surgical treatment is recommended. Because establishment of a direct systemic to coronary blood flow is expected to provide the best recovery of left ventricular function, various corrective procedures have been proposed. Subclavian-left coronary artery anastomosis appears to be a logical approach. Four patients operated on at Sainte-Justine Hospital, at an average age of 33 months (27 to 44), with an end-to-end subclavian-left coronary artery anastomosis were evaluated 6 to 46 months postoperatively. The anastomosis was patent in all cases. End-diastolic volume index (74.6 +/- 24.7 versus 122.7 +/- 15.3 ml/m2) and ejection fraction (0.58 +/- 0.07 versus 0.33 +/- 0.06) were improved significantly. Subclavian-left coronary artery anastomosis appears to meet the main criteria for an optimal physiologic correction of anomalous left coronary artery: restoration of a two-coronary artery system, improvement of left ventricular function, and likelihood of long-term patency.

Anastomosis, Surgical↗
PubMed1989

Comparison of cardiovascular adjustments to exercise in adolescents 8 to 15 years of age after correction of tetralogy of fallot, ventricular septal defect or atrial septal defect.

Surgical correction of tetralogy of Fallot (TF) has generally been associated with a reduced maximal exercise tolerance, possibly related to the ventriculotomy inherent to the intracardiac repair procedure. This study documents the exercise hemodynamics of a group of patients operated on for TF who showed similar clinical and functional characteristics, and compares these responses to those of age-matched patients operated on for an isolated ventricular septal defect (VSD) or atrial septal defect (ASD) in an attempt to better understand the role of the ventriculotomy in the exercise limitation. Thirty patients, ages 12 to 19 years, operated on before 5 years of age for complete repair of TF (n = 13), VSD (n = 7) or ASD (n = 10) and 10 age-matched control subjects underwent a progressive maximal cycling test to determine the maximal oxygen uptake (VO2 max), and completed submaximal cycling at intensities of 33 and 66% VO2 max, respectively, to determine the cardiac output (CO2-rebreathing). No significant differences in VO2 max were observed (TF = 37.6 +/- 10; VDS = 34.0 +/- 9.2; ASD = 36.5 +/- 7; controls = 41.3 +/- 6.0 ml/kg/min). The maximal heart rate, however, remained lower in all patient groups in comparison with control subjects (p less than or equal to 0.05) (TF = 178 +/- 14; VSD = 172 +/- 17; ASD = 179 +/- 16; controls = 191 +/- 12 beats/min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1989

Echocardiographic and angiographic findings in superior-inferior cardiac ventricles.

The anatomy of superior-inferior ventricles was studied in 17 patients, aged 1 day to 22 years, using echocardiography and angiography. In all patients, the right ventricle was located superiorly and the left ventricle inferiorly. The right ventricular sinus was underdeveloped in 14 of the 17 patients. Conversely, the right ventricular outflow tract was normally developed in all 17 patients. The visceroatrial situs was solitus in all patients, and it was associated with a concordant D-loop in 9 patients and with a discordant L-loop in 8. There was a high incidence of associated transposition of the great arteries (9 patients) or double-outlet right ventricle (5). Segmental combination was unpredictable, D-loop being associated with L-position of the great arteries in 4 of 8 patients and L-loop being associated with D-position of the great arteries in 4 of 9. There were only 3 concordant ventriculoarterial connections. Frequently associated anomalies included ventricular septal defect (17 patients), atrioventricular valve malformations (17) subaortic conus (14) and pulmonary outflow tract stenosis or atresia (11). Criss-cross hearts were present in only 7 patients.

Adult↗
PubMed1989

[Arrhythmia disorders after repair of ventricular septal defects. Comparison of atrial and ventricular approaches].

Post-operative disorders of conduction and of ventricular and supraventricular excitability were studied in 50 patients operated upon for ventricular septal defect (VSD). The VSD was approached by right ventriculotomy in 29 patients aged 4.4 +/- 3.1 years at surgery and 15.1 +/- 6.5 years at evaluation. The VSD was closed by the atrial route in 21 patients aged 6.6 +/- 3.9 years at surgery and 12.1 +/- 6.8 years at evaluation. Complete right bundle branch block (CRBB) was significantly more frequent in patients who underwent ventriculotomy (62 p. 100 vs 33 p. 100, p less than 0.05), but 2 late complete atrioventricular blocks were observed in patients in whom the atrial route was used. 34 p. 100 of the patients with ventriculotomy and 26.5 p. 100 of those without ventriculotomy had significant ventricular arrhythmias on Holter recordings (greater than or equal to Lown's grade 2, p = NS). The occurrence of ventricular arrhythmias in the patient population as a whole increased significantly with age at surgery and age at evaluation (p less than 0.05); this increase was also noted in each group (p = 0.06). Pre-operative right ventricular systolic pressure, severity of intraventricular disorders of conduction or duration of extracorporeal circulation and aortic clamping had no influence on the occurrence of ventricular arrhythmias. Disorders of supraventricular excitability were found in 1 patient who had ventriculotomy and in 2 patients whose VSD was corrected by the atrial route. No sinus dysfunction was observed. It is concluded that the ventricular approach of VSD significantly increases the occurrence of post-operative CRBB.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1988

Left ventricular diastolic function during the first month of life.

UNLABELLED: In order to assess possible changes in myocardial relaxation occurring during the neonatal period, M-mode echocardiograms were recorded serially in 9 normal term infants and in another group of 10 one-month-old infants. The tracings were studied with an M-mode calculator. Although individual variations were greater in the data collected during the first 24 h, no significant difference was found in the indices of diastolic function of the left ventricle during the first 4 days of age. The following changes were observed between data recorded at 4 days and 1 month, respectively: normalized peak rate of left ventricle filling, 4.03 vs. 4.71 cm/s; diastolic peak velocity of early posterior motion of aortic root, 1.89 vs. 5.15 cm/s; peak velocity of left ventricle posterior wall motion in diastole, 3.31 vs. 3.50 cm/s; mitral valve EF slope, 59.05 vs. 84.92 mm/s; left ventricle isometric relaxation time, 43.88 vs. 28.50 ms. IN CONCLUSION: (1) greater individual variations are observed in indices of left ventricle diastolic function during the first day of life, and (2) significant increase in left ventricle compliance occurs during the first month of life. These changes should play a critical role in the clinical course of newborn with cardiopulmonary disease.

Diastole↗
PubMed1988

[Cardiac pacemakers in children. 15 years' experience].

Between 1971 and 1986, 85 pacemakers were implanted at the St Justine Hospital, Montreal, in 57 young patients (25 girls, 32 boys) then aged from one day to 23 years (mean 10.3 years). The patients were followed up for periods ranging from 15 days to 13.5 years (mean 4.5 years); 119 epicardial electrodes were positioned by thoracotomy in 52 patients and by sternotomy in 5 patients; the 85 pacemaker cases were placed in the left retroperitoneal cavity. The pacemakers were programmed in modes VVI (28), AAI (1) and DDD (28). The indications for pacemaker implantation were: complete atrioventricular block in 39 cases (postoperative 16, congenital 22, acquired 1), sinus node disease in 17 cases (postoperative 13, cardiomyopathy 3, normal heart 1) and Romano-Ward syndrome in 1 case. Operated heart diseases which required pacemaker implantation were: D-transposition of the great arteries in 17 cases (complete atrioventricular block 7, sinus node disease 10), tricuspid valve atresia in 3 cases (sinus node disease 3) and tetralogy of Fallot in 3 cases (complete atrioventricular block 3). Twenty-four patients underwent a total of 33 reoperations: 21 changes of battery, 12 changes of electrodes (6 for fibrosis, 6 for breakage). Only one patient developed infection of the pacemaker case. Altogether, the incidence of complications (infection and/or breakage) was low in this series, regardless of the pacing mode. Pacing in children is now an acceptable treatment with low risk provided the indications are well selected.

Adolescent↗
PubMed1986

Value of respiratory variations of right ventricular dimension in the identification of small atrial septal defects (secundum type) not requiring surgery: an echocardiographic study.

In search of reliable criteria that could help differentiate insignificant atrial septal defects (ASDs) from those with a large shunt, M-mode echocardiograms of three groups of patients were studied retrospectively: group I = 10 normal children (mean age 5.7 years); group II = 10 patients (mean age 7 years) with small ASD in whom the decision was taken not to proceed to surgical closure, based on hemodynamic and angiographic criteria; and group III = 15 patients (mean age 7 years) with an "operable" shunt, who underwent corrective surgery. The results showed that right ventricular end-diastolic dimensions during expiration (RVDDE) were increased in all patients in group III but were normal in only 3 of the 10 patients in group II. A normal septal movement was found in all patients in groups I and II but also in five patients in group III. The variation in right ventricular diastolic dimension with respiration (RVDVR) was always normal in group II. However, in group III all patients but one had a small RVDVR (less than 6%). It was concluded that a normal RVDDE is very specific (100%) but not sensitive (30%), a normal septal movement is very sensitive (100%) and moderately specific (70.6%), and a normal RVDVR is both very sensitive (100%) and specific (94.4%) as a criterion for identification of small ASDs not requiring surgery.

Adolescent↗