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M Gueron

Publications and source records attributed to M Gueron.

At least 73 records · Page 4Linked to original sources

Isotonic (dynamic) and isometric (static) effort in the assessment and evaluation of diastolic hypertension: correlation and clinical use.

We compared the effect of two exercise stress tests on blood pressure in normal and borderline populations. The aim of the trial was to determine if isometric exercise testing by handgrip can replace the isotonic exercise test in population screening for the detection of mild and latent hypertension. The study involved 150 subjects; 62 were normotensive and 88 were borderline hypertensive. No significant statistical difference was found in diastolic pressure between the tests. In normotensive subjects, the diastolic response after isotonic effort was 79.3 +/- 9.6 mm Hg and 89.0 +/- 9.7 mm Hg after the isometric test (p less than 0.05). However, both results did not pass 100 mm Hg. In borderline hypertensive patients the diastolic response to the isotonic test was 105.6 +/- 8.8 mm Hg and after the isometric test 107.7 +/- 10.6 mm Hg (NS). The results show that the handgrip isometric test can replace the complicated isotonic test for the screening detection and evaluation of hypertensives in the population.

Adult↗

Malignant course of a benign anomaly: myocardial bridging.

A 35-year-old man, with recent onset angina, developed recurrent episodes of syncope due to ventricular tachycardia. His coronary angiogram showed normal coronary arteries and myocardial bridging of the left anterior descending causing severe systolic milking effect. Extensive invasive and noninvasive investigations did not reveal cardiac pathology other than the myocardial bridging. Electrophysiologic studies, not previously reported in myocardial bridging, demonstrated inducible sustained ventricular tachycardia at a rate of 280 beats/min. The possible relationship between the arrhythmia and the myocardial bridge is suggested. Combined medical treatment with amiodarone and diltiazem proved to be an effective alternative to surgical myotomy of the bridge.

Adult↗

Viral myocarditis simulating dilated cardiomyopathy in early childhood: evaluation by serial echocardiography.

Left ventricular dimensions and function were assessed by serial M mode and cross sectional echocardiography in ten infants and young children with heart muscle disease characterised by left ventricular dilatation and impaired systolic function presenting in congestive heart failure, severe respiratory distress, or both. The patients were followed for 8-60 months after their initial admission. The aetiology was probably viral in all cases. One patient died three weeks after diagnosis. Left ventricular size and function returned to normal in only one child; however, various degrees of improvement were found in seven others who were symptom free at follow up. This study demonstrates that serial echocardiography adequately defines this disease in infants and young children and that invasive evaluation is seldom required. Furthermore, it emphasises the fact that even in symptom free children an echocardiographic picture that is indistinguishable from dilated cardiomyopathy may persist; such patients required continued follow up.

Cardiomyopathy, Dilated↗

Salivary gland enlargement following cardiac catheterization.

Salivary gland enlargement following heart angiography is described. Previously documented salivary gland swelling was related to excretory urography or administration of iodinated tablets. We could not find any previous description of salivary gland swelling following heart angiography.

Coronary Angiography↗

Intermittent poppet dislodgment in a Braunwald-Cutter prosthesis: noninvasive diagnosis and successful surgical treatment.

A 65 year old patient had his mitral and aortic valves replaced with two Braunwald-Cutter prostheses in 1973. Seven years later, he presented with intermittent aortic insufficiency demonstrated by echocardiography, fluoroscopy and angiography. At emergency surgery, the occluders (poppets) of both prostheses were found within the left ventricular cavity. The valves were excised and replaced with Björk-Shiley prostheses and the patient recovered. Aortic occluder escape is rare and usually fatal. Mitral occluder escape of the Braunwald-Cutter prosthesis has not been described previously.

Aged↗

Systemic-pulmonary arteriovenous fistula of traumatic origin: a case report.

Arteriovenous fistulas between the systemic circulation and the pulmonary artery are extremely rare. Continuous precordial murmur is the usual clinical sign while unilateral rib notching may be the only radiologic manifestation of this condition. Selective angiographic investigation is necessary to localize the site of such an arteriovenous (AV) fistula before surgery is performed. In a review of the literature of 15 published cases, the majority were of congenital origin, with four of these systemic-pulmonary AV fistulas of traumatic origin, of which one occurred after insertion of an intercostal catheter. We describe one case of traumatic origin 9 years after percutaneous thoracic drainage for spontaneous pneumothorax, in which transcatheter embolic occlusion of the feeding arteries of an AV fistula was attempted. The advantages and the disadvantages of the nonsurgical and surgical therapeutic approaches are discussed.

Adult↗

NMR study of slowly exchanging imino protons in yeast tRNAasp.

We have monitored the exchange of imino and amino protons by NMR after quick transfer of yeast tRNAAsp in 2H2O solvent. When the concentration of exchange-catalyzing buffer is not too high, one imino proton exchanges considerably more slowly than any other (e.g., 100 hr versus 4 hr for the second-slowest imino proton at 18 degrees C in 15 mM Mg). This provides excellent conditions for identification, by the nuclear Overhauser effect, of the slowest exchanging proton, which we show to be the imino proton of the U-8 . A-14 reverse Hoogsteen tertiary-structure base pair; other slowly exchanging protons are identified as imino protons from A . U-11 and G . psi-13. In preliminary experiments, we find that the exchange of these protons is catalyzed by cacodylate or Tris buffer. The lifetimes of two other imino protons, ca. 10 min at 28 degrees C, are buffer independent. Slowly exchanging amino protons have also been observed. Correlation with the exchange of the uracil-8 imino proton suggests that they may be from adenine-14.

Base Sequence↗

Severe rheumatic mitral valve disease in children. Evaluation by echocardiography.

Severe rheumatic mitral stenosis with or without mitral insufficiency is virtually unseen in children in the affluent countries of the western world, but is not uncommon in developing countries. Fifteen cases of rapidly progressive rheumatic mitral valve disease in children are presented to illustrate the value of echocardiography in the diagnosis and evaluation of this lesion. Cardiac catheterization was performed in nine and simply confirmed the diagnosis made noninvasively. Our experience demonstrates that thorough echocardiographic examination in these cases frequently enables the examiner to assess the need for surgical intervention without cardiac catheterization.

Adolescent↗

Systolic time intervals in adolescents. Normal standards for clinical use and comparison with children and adults.

Systolic time intervals were measured in 147 healthy 13-19-year-old adolescents to derive regression equations for clinical use in this age group and to determine to what extent they differ from those of children and adults. Stepwise regression analysis showed that heart rate was the only variable consistently and significantly related to electromechanical systole (QS2), left ventricular ejection time (LVET) and preejection period (PEP). None of the other variables tested (age, height, weight, body surface area, blood pressure, hemoglobin, hematocrit and serum electrolytes), when used alone, were relevant variables in relation to QS2, LVET or PEP. The PEP/LVET ratio in adolescents was essentially independent of heart rate, as in children and adults. The regression lines for QS2, LVET and PEP in adolescents fall between those for children and adults, indicating that there is a distinct tendency toward lengthening of all the systolic time intervals with age, independent of changes in heart rate. The PEP lengthens proportionately more than the LVET, resulting in a progressive increase in the mean PEP/LVET ratio from childhood (0.30) to adolescence (0.32) and to adulthood (0.345). The precise hemodynamic factors underlying these changes with increasing age remain to be determined.

Adolescent↗