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Biomedical subjects

C Dumont

Publications and source records attributed to C Dumont.

17 recordsLinked to original sources
PubMed1979

Mechanism of rapid, shallow breathing after ozone exposure in conscious dogs.

In 10 experiments on 3 conscious dogs exercising on a treadmill, we studied the effect of ozone on base-line ventilation and on ventilatory responses to inhaled bronchoconstrictor drugs. Prior to ozone exposure, inhalation of histamine diphosphate aerosol (1%; 5 breaths) increased respiratory frequency (f) by 86 +/- 11% (mean +/- SE), and inhalation of prostaglandin F2 alpha (PGF2 alpha) aerosol (0.1%; 5 breaths) increased f by 74 +/- 16%. Immediately after ozone exposure %0.65 ppm; 2 h), steady-state base line f was increased by 120 +/- 18% and tidal volume (VT) was decreased by 43 +/- 5%. When conduction in the cervical vagus nerves (that were exteriorized permanently in skin loops) was blocked by cooling, these changes caused by ozone were abolished (P greater than 0.05). The increased responses to both histamine and PGF2 alpha aerosols after ozone were unaffected by pretreatment of isoproterenol aerosol (0.5%; 15 breaths), but were completely abolished by vagal cooling. Our studies indicate that ozone-induced rapid, shallow breathing and the increased ventilatory responses to inhaled histamine and PGF2 alpha aerosols are mediated through vagal afferent pathways.

Aerosols↗
PubMed1975

A radiologic index of pulmonary arterial hypertension.

A new radiologic index indicative of pulmonary artery hypertension is presented. It was obtained by measuring the horizontal distances from the midline to the first divisions of the right and left pulmonary arteris, and dividing the sum of these distances by the maximum transverse diameter of the thorax. The index was significantly different in groups with and without pulmonary hypertension and was abnormal (above 38 percent in 111 of 150 patients with cardiovascular disease and pulmonary arterial hypertension (PAH). None of the cases with increased pulmonary flow from cardiac shunts but normal PAP had an anbormal index. Thus, an abnormal index suggested PAH but correlated poorly with the extent of hypertension.

Adolescent↗
PubMedDate not supplied

[Indications and radiological measurements in the evaluation of pulmonary artery hypertension].

Different radiologic indexes and measurements proposed in the evaluation of pulmonary artery hypertensión (PAH) were reviewed. The postero-anterior chest roentgenograms of 250 subjects were studied. In all cases the pulmonary artery pressure was known from cardiac catheterization. The diameter of the right pulmonary artery was larger than 1.7 mm. in 45% of cases with PAH. The pulmonary-lobar-transverse-thoracic index (PL/T) was abnormal (+38%) in 74% of cases with PAH, and normal in cases with increased pulmonary flow. The index of Ozawa, distance between the midline and the more prominent portion of the pulmonary arch, related to the transverse diameter of the left hemithorax overestimated the mean pulmonary pressure when normal and underestimated the same with PAH. A new index is described. The relation of the right pulmonary artery with the transverse diameter of the hemithorax on the same side (r/h index). It was abnormal in 24% of the cases with PAH and it was always normal in cases with increased pulmonary flow. The more sensitive and specific measurement seems to be the PL/T index.

Adolescent↗
PubMedDate not supplied

[Stable fibrous subaortic stenosis].

The authors studied 37 patients belonging to the Pediatric Cardiology Service of the Institute National of Cardiology who were carriers of fixed fibrinous subaortic stenosis. The diagnosis was established by surgery or autopsy. Isolated subvalvular obstruction was found in 24 patients (63%), which represents the most important number of cases in the literature. The analysis of the 24 cases permitted important conclusions: 1. All the patients had systolic thrills in the suprasternal hollow and carotidinous pathways. 2. No case had protosystolic click. In all, the murmur's epicenter was in the 3rd and 4th IIS in the parasternal line, a fact which can lead to a mistaken diagnosis of interventricular septal defect. 66.6% of the patients had a diastolic murmur heard in the aortic focus, a secondary accompaniement to secondary valvular aortic insufficiency. The intensity of the second aortic sound held an inverse relationship to the magnitude of the gradient. The presence of paradoxic splitting of the second heart sound as well as prolongation of the expulsion period in the carotidogram are indexes for the severity of the obstruction. 3. A relationship between the severity of the lesion and the dilatation of the left atrium was found. The cardiomegaly had no relationship to the severity of the obstruction with the increase in ventricular telediastolic pressure or to the evolution time. 4. An adequate hemodynamic study permits evaluating and locating the site of the obstruction. Likewise, precise ventriculography appraises the nature of the narrowing. 5. Aortic regurgitation is located at the valvular level. Aortography permits its affirmation. Probably the stream coming from subvalvular stenosis produces fibrosis or asynchronism in the closing of the aortic valves. 6. Surgical treatment offers excelent perspectives in mortality as well as reducing the gradient. None of our patients operated on had hospital or later death. 7. Postoperatory evaluation was performed on six patients, and by means of measuring the gradient between the left ventricle and the aorta, the good surgical results could be demonstrated. 8. The natural evolution of patients with fixed fibrous subaortic stenosis is similar to that of other forms of congenital aortic stenosis. Taking into consideration this concept, and before the low risk (0%) in this type of surgery, this is the treatment of choice.

Adolescent↗
PubMedDate not supplied

[Familial occurrence of Wolff-Parkinson-White syndrome. Report of a family group and review of the literature].

A family group of nine members was studied, two of which had W-P-W syndrome; the father type A; and the son type B. These two patients were studied from the clinical electrocardiographic and vectocardiographic point of view; and they were subject to hisian electrogram recordings. The atrial-ventricular conduction under basal conditions and during atrial stimulation is analyzed. In the first case, potential H is registered after the beginning of delta wave of the ventricular complexes in lead II. In th second case, atrial-ventricular conduction can only occur through the abnormal via (no H potential and register of delta wave in the periferial simultaneous lead), or only through the normal via (evidence of potential H with a normal H-V interval and no delta wave in the periferial line of control). The bibliography of the observation that in most family groups described up until now, there is a good correlation concerning sex. This gives the impression to be a genetic disorder linked to sex.

Adult↗
PubMedDate not supplied

[Fixed fibrous subaortic stenosis. Postoperative evaluation].

Fibrous sub-aortic stenosis in 19 patients surgically treated is discussed. The clinical, radiologic, EKG and cardiac catheterization data in the pre and post-operative evaluations are reviewed. There were no surgical deaths in this series. In 14 cases post-operative cardiac catheterization was carried out, in 11 patients a significant decrease in the gradient was found. In 4 cases pharmacological testing was done during catheterization before and after surgery, without significant change in gradients.

Adolescent↗
PubMedDate not supplied

[Aneurysm of the membranous portion of the interventricular septum].

The membranous portion of the interventricular septum represents the final phase of the ventricular growth. It is situated between the orifice of the coronary sinus and the supraventricular crest; immediately below the right aortic semilunar valves and not the coronary. Four cases of aneurism of the membranous portion of the interventricular septum are presented; in two, the diagnosis was made by angiocardiography study and in the rest it was made with the findings of an autopsy. All were of the female sex. Two patients presented a systolic murmur in the low mesocardia; three had heart failure, two of which were secondary to an arteriovenous short circuit through an interventricular communication, and the other due to alternations in the automatism and in the atrioventricular circulation. One case had W-P-W, type A and during its evolution presented paroxysms of atrial fibrillation and flutter, variable degrees of atrioventricular block with Stokes-Adams syndrome and ventricular fibrillation. In one case an obstruction at the level of the outflow tract of the right ventricle was suspected through phonocardiographic studies, and was confirmed subsequently with hemodynamic study. This same case presented a protosystolic aortic snap, at 0.13-0.14 sec. of the q wave of the electrocardiogram, described as of value for the diagnosis of this malformation. In two cases the angiocardiographic study showed the presence of the aneurism in the membranous portion of the interventricular septum, in one, it was visualized in the posterioanterior projection and in another in the lateral. One of the specimens had the aneurism adhered to the tricuspid septal valve, and also a fissure which communicated the left ventricle with the right atrium. In the other, the aneurismal sac was located below the septal valve of the tricuspid, producing a distortion in the anatomical architecture of the atrioventricular orifice.

Autopsy↗