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Biomedical subjects

J C Fouron

Publications and source records attributed to J C Fouron.

135 records · Page 8Linked to original sources
PubMed1967

[Congenital peripheral pulmonary stenosis. Presentation of 16 cases and review of the literature].

Sixteen cases of peripheral pulmonary stenosis have been studied clinically and by cardiac catheterization. Diagnosis has been proved in all cases by manometric measurements and/or cineangiocardiography. All patients except two were below 2 years of age. Ten cases were of type I, i.e. the stenosis was localized to the pulmonary trunk or its main branches. Six patients were of type III, i.e. they had diffuse stenosis of the pulmonary arterial tree. The physical findings, which in many cases are typical and include the presence of a systolic murmur over both lung fields, should alert the physician to the diagnosis at the bedside. At cardiac catheterization the configuration of the pressure tracing in the main pulmonary artery is typical, showing an abrupt rise and fall of the systolic wave followed by a low situated dicrotic notch. There is no doubt that in the past many cases of peripheral pulmonary stenosis have been wrongly diagnosed as "essential pulmonary hypertension".

Child, Preschool↗
PubMedDate not supplied

Cerebral arteriovenous malformation: prenatal and postnatal central blood flow dynamics.

Using the Doppler technique, this study compared the prenatal and postnatal flow patterns of an infant with cerebral arteriovenous (AV) malformation. Fetal right ventricular end-diastolic dimension was 1.7 cm with right ventricular ejection equaling 66% of the combined cardiac output. Diastolic flow was reversed in the fetal aortic isthmus but forward-moving in the descending aorta, resulting in a watershed phenomenon. In the carotid arteries an increased forward diastolic flow was noted while the internal jugular vein exhibited a pulsatile arterial type of flow. The pulsatility index of the umbilical artery was normal. After birth and closure of the ductus arteriosus, the output from both ventricles was equally increased, and retrograde diastolic flow was then observed in the descending aorta. In conclusion, specific fetal features of cerebral AV malformation are increased right ventricular output probably related to the increased superior vena cava return, watershed phenomenon in the descending aorta causing the right ventricle to perfuse both the lower and upper body, and preserved umbilical circulation.

Adult↗
PubMedDate not supplied

Generation of reactive O2 species in the myocardium of newborn lambs following intrauterine increase in right ventricular pressure.

Fetuses with pulmonary stenosis and constriction of the ductus arteriosus or the recipient twin in the context of a twin-to-twin transfusion syndrome may present with severe right ventricular myocardial dysfunction. Free O2 radicals are known to be increased in hypertrophied adult myocardium secondary to an increase in endocavitary pressure. This study investigates whether products of reactive O2 species generation are abnormally elevated in the myocardium of fetuses with increased right ventricular pressure. Banding of the main pulmonary artery was performed in five fetal lambs at 90 to 100 days of gestation. Three other animals had a sham intervention and were used as controls. Postoperative observation lasted on average 42 days (range 33-49 days). The levels of hydroperoxides were found to be significantly higher in the right ventricle of the stenosed lambs (6.6 +/- 3.5 nmol/mg protein) compared to the left ventricle of the same lambs (0.7 +/- 0.7 nmol/mg protein), and compared to the right (0.12 +/- 0.1 nmol/mg protein) and the left (0.5 +/- 0.8 nmol/mg protein) ventricles of the controls. It is concluded that during fetal life, an increase in right ventricular pressure is associated with a marked accumulation of products of reactive O2 species generation in the right ventricular myocardium.

Animals↗
PubMedDate not supplied

Prenatal diagnosis of junctional ectopic tachycardia.

The congenital form of junctional ectopic tachycardia has never been reported during the prenatal period. We describe a case in which the diagnosis could be ascertained in utero with the superior vena cava/ascending aorta Doppler approach. The diagnosis was based on the evidence of ventricular tachycardia with atrioventricular (AV) dissociation and the simultaneous occurrence of atrial and ventricular contractions during an episode of tachycardia with 1:1 AV relationship.

Adult↗
PubMedDate not supplied

Computerized measurement of Doppler flow velocity waveforms: validation of a new system.

Manual measurement of Doppler flow velocity waveforms is time-consuming and carries unavoidable and significant intraobserver and interobserver variability. Those drawbacks limit the routine use of Doppler-derived indexes of systolic and diastolic function. This report describes a system that performs automatically all relevant measurements currently obtained from mitral, tricuspid, aortic, and pulmonary waveforms. One hundred and sixty waveforms, obtained from patients whose ages ranged from a 19-week fetus to a 21-year-old adult, were measured both manually and automatically. High correlations were found for all types of measurement: r = 0.993 for velocity measurements, r = 0.995 for time interval measurements, r = 0.881 for acceleration measurements, r = 0.867 for pressure half-time measurements, and r = 0.993 for flow integral measurements. When compared with manual measurements, automatized measurements displayed significantly lower intraobserver and interobserver variabilities for all types of measurements. Finally, the automatized measurement system cuts the time spent by a factor of more than five. Such a system of computerized measurements of Doppler flow velocity waveforms should become increasingly valuable as both a clinical and a research tool.

Adult↗
PubMedDate not supplied

Assessment of fetal pulmonic stenosis by ultrasonography.

This study was designed to determine (1) the value of Doppler echocardiography in depicting the presence of a fetal pulmonary stenosis, (2) its reliability in the assessment of the severity of the lesion, and (3) the usefulness of additional markers from the left side of the heart as criteria of severity. Fourteen pregnant ewes were included in this study (gestational age, 90 to 120 days). Banding of the fetal main pulmonary artery created mild (n = 3), moderate (n = 3), and severe (n = 5) stenosis. Three lambs were sham operated. Intrauterine fetal Doppler echocardiographic data obtained 15 days after surgery were compared with preoperative values. Peak velocities recorded through the band increased linearly from baseline in the groups with mild and moderate stenosis but did not show any further increase in the group with severe stenosis. Compared with the sham-operated group, right ventricular output in the group with stenosis was either similar or reduced significantly. The increase in right ventricular free wall thickness was significantly greater in the groups with stenosis compared with that of the sham-operated group; the correlation with the degree of severity was r = 0.65 and p < 0.05. A A stronger positive correlation was found between the severity of stenosis and aortic valve diameters: r = 0.82 and p < 0.01. The strongest correlation was found for right ventricular/left ventricular outputs (r = 0.92; p < 0.001). Thus Doppler peak velocities through the obstruction can help detect pulmonic stenosis but are not reliable for the assessment of its severity during fetal life. Other ultrasound measurements such as the size of the aortic anulus and especially the ratio of right ventricular/left ventricular output could be used as sensitive markers of the severity of stenosis.

Animals↗