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Biomedical subjects

A J Rein

Publications and source records attributed to A J Rein.

At least 55 records · Page 3Linked to original sources
PubMed1987

Left ventricular mechanics in the normal newborn.

The transition from fetal to neonatal circulatory status is accompanied by marked alteration in relative right and left ventricular systolic and diastolic pressure. These alterations would be expected to influence both global and regional performance of the left ventricle. To address this issue, sequential two-dimensional echocardiographic studies were performed in normal newborns during the first days of life. Global and regional left ventricular wall motion were quantified by computer digitization with the use of an automated edge detection algorithm and a floating-center-of-mass model. Comparison was made with a control group of normal infants and young children and the sequential change over the first 5 days of life was assessed. Newborns were found to have a circular left ventricular configuration at end-diastole beginning on day 1. At end-systole, however, there was significant left ventricular distortion due to septal flattening, which persisted until day 3 and resolved entirely by day 5 of life. Regional wall motion analysis demonstrated a corresponding augmentation of septal and contralateral left ventricular free wall systolic movement during the first days of life, with a normal pattern attained by day 4. Due to the nonhomogeneity of the left ventricular wall motion in the first few days of life, standard single-dimension shortening fraction provided an unreliable measure of global left ventricular performance before day 4. Thus, systolic right ventricular hypertension at a level sufficient to distort the left ventricular configuration is present until day 4 or 5 of life, resulting in altered left ventricular regional wall motion. As a result, usual M mode echocardiographic assessment of left ventricular function is unreliable in this age group.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1987

Anomalous origin of left coronary artery from pulmonary artery. Ligation versus establishment of a two coronary artery system.

Between 1959 and 1985, 24 patients (mean age 38 months, range 15 days to 13 years) with anomalous origin of the left coronary artery from the pulmonary artery as an isolated lesion were treated surgically at Children's Hospital, Boston. In 11 cases a left coronary-to-aortic tunnel was created with a pulmonary artery baffle (Takeuchi) with no deaths either early or late over a mean follow-up period of 18 1/2 months. Late complications of this procedure include moderate aortic regurgitation (one), supravalvular pulmonary stenosis (two-one required a second operation), obstructed baffle (one-asymptomatic). In 11 cases of coronary ligation or ostial closure there was a 27% early mortality and a 25% late mortality over a mean follow-up period of 10 1/2 years. Late complications include residual shunt (three-two required a second operation), severe mitral regurgitation (one), and recurrence of angina (one). Two patients had other procedures. Both early and late deaths occurred in the group who had congestive heart failure and who had simple ligation. Five infants who had profoundly depressed ventricular function and moderate to severe mitral regurgitation, together with widespread Q waves on electrocardiogram, showed a dramatic improvement in ventricular function after the Takeuchi procedure. The Takeuchi procedure is a simple and effective means of establishing a two coronary artery system in the child with anomalous origin of the left coronary artery from the pulmonary artery. This procedure is particularly recommended over coronary ligation in patients in congestive heart failure.

Adolescent↗
PubMed1986

Severe hydrops fetalis due to congenital supraventricular tachycardia.

Intrauterine supraventricular tachycardia is one of the main causes of non-immunological intrauterine hydrops fetalis. Without early diagnosis and treatment it may terminate in fetal death or delivery of a baby with severe hydrops and extreme heart failure. With the improvement in non-invasive imaging techniques in prenatal medicine, this condition can be diagnosed early and treated successfully. A case is described of such a newborn diagnosed in utero and treated before and after delivery, and the different therapeutic approaches to congenital supraventricular tachycardia are discussed.

Adult↗
PubMed1986

Cardiac output estimates in the pediatric intensive care unit using a continuous-wave Doppler computer: validation and limitations of the technique.

We compared the cardiac index obtained by means of a continuous-wave Doppler computer with simultaneous thermodilution measurements in 25 children in the pediatric intensive care unit (40 observations). The aortic diameter was measured at various levels to determine which provided the best measure of cardiac index. The Doppler measurements were performed independently by a physician trained in Doppler cardiography and by a nurse with no experience in echocardiography. Both the nurse and physician obtained high-quality flow velocity recordings in all patients in a mean time of 5 minutes or less. Cardiac index and total systemic vascular resistance measured by means of Doppler and thermodilution techniques were highly correlated (r = 0.86 and r = 0.93, respectively). The highest correlation was obtained when Doppler cardiac index was computed by means of the internal diameter measured at the aortic anulus. There was no significant difference between the nurse's and physician's measurements. We conclude that cardiac index can be accurately determined in the pediatric intensive care unit by means of continuous-wave Doppler computer, even when operated by personnel not trained in Doppler cardiography.

Cardiac Output↗
PubMed1985

Symptomatic sinus bradycardia in infants with structurally normal hearts.

Sixteen infants, ages 6 weeks to 23 months, were evaluated because of syncopal attacks (n = 6), apneic episodes (n = 3), or a combination of syncope, apnea, or "convulsions" (n = 7). Comprehensive metabolic and neurologic investigations yielded negative results in 15 infants; in one, an abnormal EEG was recorded. Severe sinus bradycardia, complete sinus arrest, junctional escape rhythm, or ventricular escape rhythm was found in four patients, and permanent multiprogrammable pacemakers were implanted. Follow-up for 6 to 24 months with ventricular demand pacing showed complete cessation of attacks in two infants and marked improvement in two.

Apnea↗
PubMed1984

Incidence of aspiration in endotracheally intubated infants and children.

A prospective study is reported to examine the incidence of aspiration in 50 infants and children intubated with a noncuffed endotracheal tube in a multidisciplinary PICU. Aspiration was assessed by applying Evans blue dye on the tongue and searching for the dye during suctioning, in the endotracheal aspirate. Twenty-nine (58%) were medical patients and 21 (42%) surgical; ages ranged between 25 h and 4 yr (mean 18.5 months). Respiratory failure was the major indication for endotracheal intubation and mechanical ventilation in 26 (52%) of the patients, hyperventilation for increased intracranial pressure in 12 (24%), congestive heart failure in 8 (16%), and protection of airway in deeply comatose patients in 4 (8%). The patients remained intubated from 18 h to 12 days (mean 70.4 h). Evidence of aspiration was found in 8 (16%) of the patients, accompanied by changes in chest x-ray in 5 (63%) patients and a significant fall in PO2 in 3 (37%). Aspiration was not significantly affected by the presence of a nasogastric tube, level of consciousness or ventilator setting. We conclude that noncuffed endotracheal tubes of proper size that adequately seal the trachea and effectively prevent clinically significant aspiration in endotracheally intubated infants and children.

Animals↗
PubMed1984

Left ventricular function during asynchronous ventricular pacing: a radionuclide study.

This study was undertaken to assess ventricular volumes and function by radionuclide angiography during asynchronous ventricular pacing in a group of 22 patients who needed an artificial pacemaker. 14 had ischaemic heart disease and 8 had primary disturbances of conduction of the impulse-forming system. The transition from sinus to a paced rhythm or increasing the pacing rate had little effect on patients with primary conduction disturbances. In contrast, in patients with ischaemic heart disease, the transition to a paced rhythm decreased significantly left ventricular end-diastolic (15.3 +/- 4.7%) and stroke (26.3 +/- 4%) volumes, ejection fraction (9.0 +/- 4.4%), and cardiac output (21.0 +/- 3.9%). Pacing at a progressively increasing heart rate showed that each patient had an optimal rate of pacing.

Aged↗
PubMed1983

Subcostal M-mode computerised echocardiography. An alternative or complementary approach to parasternal echocardiography?

Subcostal M-mode echocardiography has been suggested as a method for assessment of left ventricular size and function. Parasternal and subcostal measurements (direct and derived) of left ventricular function were compared in 30 healthy young subjects. We calculated instantaneous left ventricular diameter and wall thickness every 10 ms for both the subcostal and parasternal approaches using a computer program for echocardiographic digitisation and compensation. All variables were filtered to calculate instantaneous first derivative (velocity) and logarithmic derivative (normalised velocity). The program provided normal values for computerised variables of left ventricular function from the subcostal approach. It was found that there was no identity and no correlation or a poor one between subcostal and parasternal left ventricular internal diameters and volumes. The parietal wall thickness was significantly greater using the subcostal approach, and the comparative velocities study showed striking variations between the two approaches, especially in diastole, where the peak lateral wall thinning rate was 20% lower than the posterior thinning rate. We conclude that for a normal and young population, the subcostal and standard parasternal data cannot be used interchangeably for precise studies of left ventricular function. The subcostal approach, however, provides useful complementary information about lateral wall motion.

Adult↗
PubMed1982

Regional left ventricular ejection fraction from real-time two-dimensional echocardiography.

We studied regional left ventricular contraction patterns and ejection fraction from real-time two-dimensional echocardiograms in 8 normal subjects, 11 patients with coronary artery disease and 2 with congestive cardiomyopathy. The ventricle was divided into 12 regions and for each region, we calculated ejection fraction using a method which integrated the incremental volumes of a series of hemicylinders constructed within that region. The data obtained were displayed graphically to provide a detailed picture of regional ventricular function. Normal subjects had a uniform regional ventricular pattern (regional ejection fraction 54-74%). In patients with coronary disease, we found varying degrees of regional ventricular contraction abnormalities. In congestive cardiomyopathy global hypokinesis was present, and regional ejection fraction was reduced in all areas (11-39%). The study showed that two-dimensional echocardiography is a useful non-invasive bedside technique which may provide detailed quantitative information relating to regional left ventricular contraction abnormalities.

Adolescent↗
PubMed1982

Quantitation of regional ventricular asynergy using real-time two-dimensional echocardiography.

Real-time two-dimensional echocardiography was used to identify and quantitate regional left ventricular dysfunction in 12 patients with coronary artery disease. THe extent of regional ventricular asynergy was expressed as the percentage of the left ventricular circumference contracting abnormally. The findings were compared with those obtained from cardiac catheterization and left ventriculography. The severity and extent of echocardiographic asynergy correlated closely with that observed on the angiocardiogram (r = 0.96, P less than 0.001). There was also a significant relationship between echocardiographic and angiocardiographic ventricular volume (r = 0.81, P less than 0.001) and ejection fraction (r = 0.79, P less than 0.01). Real-time two-dimensional echocardiography provided a useful noninvasive technique for the identification and quantitation of the extent of regional ventricular dysfunction.

Aged↗
PubMed1982

Echocardiography of the inferior vena cava in healthy subjects and in patients with cardiac disease.

Echocardiograms were recorded from the inferior vena cava (IVC) in 45 subjects: 10 normal subjects, 8 patients with cardiac volume overload due to anemia, 4 with severe right heart failure, 6 with significant tricuspid incompetence (TI), 7 with pericardial effusion (PE) and 10 with left-sided cardiac disease. The IVC was readily identified on the echo recordings made 1 to 2 cm below the junction of the hepatic veins. In normal subjects a double wave form was present on the IVC echogram for each beat: the waves corresponded to the "a' and "v' waves of the IVC pressure pulse tracing. The IVC diameter decreased on inspiration (P less than 0.01), particularly of the "x' descent (P less than 0.001). In patients with severe right heart dysfuction, the IVC was dilated (TI: P less than 0.02; PE: P less thaN 0.003; CMO: P less than 0.001), having lost its waveform and with diminished respiratory variation. There was, however, considerable overlap between the normal subjects and the different patient groups. In two of the patients with tamponade, the IVC did not empty upon inspiration, and pericardiocentesis was followed by a return of the waveform and normal respiratory changes. IVC dimensions were normal in patients with anemia and in those with left heart disease. The results of the study showed that the echogram may provide simple and useful measurements of IVC size and function.

Adolescent↗