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Biomedical subjects

E Grenadier

Publications and source records attributed to E Grenadier.

At least 55 records · Page 3Linked to original sources

Sinus node dysfunction in a healthy pediatric population.

ECG recordings of 624 healthy children (age range 6 to 12 years) from a rural population were analyzed for evidence of sinus node dysfunction. Twelve children were found to have the disorder and they underwent further assessment in order to establish any etiological factors or anatomical abnormalities. All the children were asymptomatic and physical examination was completely normal. Standard ECG taken during 24-h monitoring demonstrated that the most common finding, seen in 10 of 12 patients, was that of sinus arrest. Second-degree sinoatrial exit block, Mobitz type I, occurred in four children and Mobitz type II was seen in three. Two of the children were found to have holosystolic mitral valve prolapse, which was in the normal frequency range for a population of healthy children. After a 2-year follow-up and reassessment, there was no change in the symptomatology, the ECG tracings or the physical findings of any of the children.

Arrhythmia, Sinus↗

M-mode and two-dimensional contrast echocardiography in adult patients with atrial septal defects.

M-mode and two-dimensional echocardiographic studies, with and without contrast injection, were performed in 14 adult patients with clinical and radiological signs of atrial septal defects. Two-dimensional contrast echocardiography was found to be the most sensitive technique, allowing a definitive diagnosis to be made noninvasively in 12 patients (86%) of those patients studied. M-mode contrast echocardiography demonstrated an atrial shunt in 6 patients (43%). Regular two-dimensional echocardiography produced a high proportion of false-positive and false-negative results, while the findings on M-mode echocardiography are sensitive but nonspecific. All 14 patients described had the diagnosis confirmed on cardiac catheterization. Performance of the Valsalva maneuver during contrast echocardiography was found to be diagnostically unhelpful. The findings suggest that contrast echocardiography, particularly two-dimensional, is an effective, noninvasive diagnostic technique to be applied on clinical suspicion of atrial septal defects.

Adult↗

The roles of serum myoglobin, total CPK, and CK-MB isoenzyme in the acute phase of myocardial infarction.

Frequent blood samples were drawn for determination of serum myoglobin, creatine phosphokinase (CPK), and the MB isoenzyme of CPK (CPK-MB) in patients with acute myocardial infarction (AMI). Significantly elevated levels of myoglobin were present 1.5 hours following onset of chest pain and predated elevations of CPK and CPK-MB by 3 hours. No evidence of the previously described "staccato" phenomenon was found. Due to very frequent blood sampling, a detailed picture of the evolution over time of the above indices was obtained. Significant differences were found in the biochemical profile of anterior wall infarction and diaphragmatic wall MI. A time-sensitivity curve (showing sensitivity of the assay at each time following onset of symptoms) was obtained for myoglobin, CPK, and CPK-MB. It appears that myoglobin is the most sensitive biochemical indicator of AMI in its early phase and since it decreases rapidly back to normal values, it can serve as an invaluable aid in the diagnosis of reinfarction and infarct extension. CPK-MB is a less sensitive indicator of MI but has the advantage of greater specificity.

Acute Disease↗

The prevalence of ruptured chordae tendineae in the mitral valve prolapse syndrome.

Echocardiographic studies were performed on 134 consecutive patients with idiopathic mitral valve prolapse syndrome. Fifteen patients (11.2%) were noted to have ruptured chordae tendineae on M-mode examination and in 12 of them the diagnosis was confirmed by bidimensional studies. Only four patients were referred for surgery as a result of severe mitral regurgitation. At operation one patient was found to have rupture of the anterior mitral chorda and the other three had posterior mitral chordal rupture. Eleven patients with chordal rupture had either mild symptoms or were completely asymptomatic. It is concluded that chordal rupture in patients with the mitral valve prolapse syndrome does not always result in severe hemodynamic deterioration and may go undetected unless a high index of suspicion is maintained. Serial echocardiographic studies may reveal the natural history of this condition in asymptomatic patients.

Adolescent↗

Two-dimensional echocardiographic study of right ventricular outflow and great artery anatomy in pulmonary atresia with ventricular septal defects and in truncus arteriosus.

In this study, we reviewed M-mode and two-dimensional (2DE) echocardiographic observations in 13 patients with pulmonary atresia with ventricular septal defect and in six patients with truncus arteriosus in order to attempt to identify echocardiographic features distinguishing these two abnormalities in which no anatomic connection exists between the right ventricle and the pulmonary artery. M-Mode features compatible with the diagnosis of pulmonary atresia with a ventricular septal defect (VSD) were a small but identifiable space anterior to the aorta and/or immobile pulmonic valve echoes appearing to open during diastole rather than systole. By 2DE, the proximal and distal segments of the right ventricular outflow tract could be imaged and the length of the atretic segment estimated. In truncus arteriosus, no outflow tract of the right ventricle could be identified by 2DE or M-mode echocardiography, and the origin of the pulmonary artery from the truncus could be imaged directly in four patients with type I and in one patient with type II truncus. Abnormalities of the truncal valve were also present and were imaged by 2DE in three of our five patients. Our study identified specific echocardiographic criteria for diagnosing truncus arteriosus and pulmonary atresia with VSD and for differentiation between them.

Child↗

Detection of deterioration or infection of homograft and porcine xenograft bioprosthetic valves in mitral and aortic positions by two-dimensional echocardiographic examination.

Results of two-dimensional echocardiographic examinations were compared with angiographic, hemodynamic and surgical results in 44 patients with bioprosthetic valves in mitral and aortic positions who were undergoing elective or urgent reinvestigation 24 to 87 months (mean 34) after implantation. In these patients, there were 18 homograft aortic valves in the aortic position, 9 stent-mounted homograft aortic valves in the mitral position, 13 porcine xenograft valves in the mitral position and 12 in the aortic position. Poor cusp support, gross fluttering and prolapse of cusps behind or below the anulus identified aortic insufficiency by two-dimensional echocardiography in six patients with an aortic homograft and four patients were identified with insufficiency of a stent-mounted aortic homograft in the mitral position. Two-dimensional echocardiographic examination revealed mitral stenosis in three patients with a porcine xenograft valve in the mitral position and suggested mitral insufficiency in two others. Bacterial endocarditis on homograft or porcine xenograft valves was associated with easily imaged vegetations by two-dimensional echocardiography in 10 patients. Despite difficulties in imaging valve cusps, and the skill required to obtain good echocardiographic images of bioprosthetic valves, significant valve deterioration or infected prostheses were quite effectively imaged by two-dimensional echocardiography in this study.

Adolescent↗

Noninvasive prediction of transvalvular pressure gradient in patients with pulmonary stenosis by quantitative two-dimensional echocardiographic Doppler studies.

Recent studies suggest that maximal Doppler velocities measured within the jets that form downstream from stenotic valves can be used to predict aortic valve gradients. To test whether the Doppler method would be useful for evaluation and management of pediatric patients with right ventricular outflow obstruction, we evaluated pulmonary artery flow before catheterization in 16 children with pulmonary valve stenosis. We used a 3.5-MHz, quantitative, range-gated, two-dimensional, pulsed, echocardiographic Doppler scanner with fast Fourier transform spectral output and a 2.5-MHz phased array with pulsed or continuous-mode Doppler. Peak systolic pulmonary artery flow velocities in the jet were recorded distal to the domed pulmonary valve leaflets in short-axis parasternal echocardiographic views. The pulsed Doppler scanner, because of its limitations for resolving high velocities, could quantify only the mildest stenoses; but, especially with the continuous Doppler technique, a close correlation was found between maximal velocity recorded in the jet and transpulmonary gradients between 11 and 180 mm Hg. A simplified Bernoulli equation (transvalvular gradient = 4 x [maximal velocity]2) proposed by Hatle and Angelsen could be used to predict the gradients found at catheterization with a high degree of accuracy (r = 0.98, SEE = +/- 7 mm Hg). Our study shows that recording of maximal Doppler jet velocities appears to provide a reliable measure of the severity of valvular pulmonic stenosis.

Adolescent↗

Prediction of the severity of left ventricular outflow tract obstruction by quantitative two-dimensional echocardiographic Doppler studies.

In this study we explored the use of continuous wave Doppler echocardiography guided by simultaneous two-dimensional echocardiographic imaging as a method for noninvasively estimating pressure gradients in patients with discrete forms of left ventricular outflow tract obstruction. We studied 16 children, ages 6 months to 17 years, with valvular aortic stenosis (n = 12) or with discrete subaortic stenosis (n = 4) and compared maximal Doppler velocities in the aorta with pressure gradients obtained at cardiac catheterization. Examinations could be performed from the suprasternal notch view or from the apical left ventricular outflow tract view with equal accuracy for the study of flow in the left ventricular outflow tract, and results were comparable in both views. With a simplified Bernoulli relationship (gradient = 4 X [maximal velocity]2), results suggested that Doppler echocardiography could be used to predict the severity of obstruction in our patients with a correlation coefficient of r = .94 (SEE +/- 7.5 mm Hg) between Doppler-estimated gradients and gradients obtained at catheterization. The method appears promising for initial evaluation and for serial management of patients with discrete forms of left ventricular outflow tract obstruction.

Adolescent↗

The efficacy of Ajmaline in ventricular arrhythmias after failure of lidocaine therapy in the acute phase of myocardial infarction.

Forty-three patients in the acute phase of myocardial infarction who were resistant to conventional doses of lidocaine received Ajmaline intravenously (50 mg bolus followed by constant infusion rate of 1-1.5 mg/min). Dangerous ventricular arrhythmias were abolished in 72% of this group of patients (group A). In the remaining patients (28%), Ajmaline was found to be ineffective (group B). There was no reduction of systolic or diastolic blood pressure and there was an insignificant increase in heart rate. Atrio-ventricular or intraventricular conduction defects appeared in 46% of the patients described. There was a statistically significant increase in occurrence of heart blocks in group B patients and among these complete left bundle branch block (CLBBB) was the most prevalent. Atrio-ventricular or intraventricular conduction defects were transient, appearing between 8-36 h (mean 23 h), and were not accompanied by reduction of ventricular rate. Conduction defects disappeared within several hours (up to 24 hours) after Ajmaline was discontinued. It is concluded that Ajmaline administered by this regimen is an effective alternative agent for patients with ventricular arrhythmia not controlled by lidocaine in the acute phase of myocardial infarction.

Ajmaline↗

Mitral valve echocardiographic pattern within the left atrium.

In a patient with a left atrial myxoma, the tumor adhered to the anterior leaflet of the mitral valve. This caused movement of the tumor's stalk in the left atrium in a pattern similar to that of a mitral valve in M-mode echocardiography. An accurate diagnosis was made by cross-sectional echocardiography and confirmed at surgery.

Echocardiography↗