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Biomedical subjects

A B Houston

Publications and source records attributed to A B Houston.

50 records · Page 3Linked to original sources
PubMed1985

Clinical value of Doppler echocardiography in the assessment of adults with aortic stenosis.

Continuous wave Doppler echocardiography was used to study 41 adults with clinically suspected aortic stenosis undergoing cardiac catheterisation. Non-invasive assessment of the severity of stenosis was made before catheterisation using electrocardiograms, chest radiographs, and cross sectional echocardiography in addition to clinical examination and assessment modified, where appropriate, by the result of the Doppler examination. Catheterisation gradients were obtained in 33 patients and correlated well with those obtained by Doppler examination particularly when simultaneous recordings were obtained. All patients with surgically significant stenoses were identified by non-invasive assessment including Doppler examination and overestimation was not found in any patient with a less than significant stenosis. Thus surgery can be recommended in patients with aortic stenosis without the need for previous cardiac catheterisation.

Adolescent↗
PubMed1983

Positioning of umbilical arterial catheters with ultrasound.

Fifty six infants were studied by ultrasound, 22 during the placement of the umbilical artery catheter. The descending aorta, bifurcation, common iliac arteries, and the intra-arterial catheter could be clearly seen. We recommend that the catheter tip be placed 5-10 mm above the aortic bifurcation thus avoiding the major branches of descending aorta.

Aorta, Abdominal↗
PubMed1981

Two-dimensional echocardiography in infants with persistent truncus arteriosus.

Two-dimensional echocardiography was used to study a consecutive series of 13 infants with persistent truncus arteriosus. In all a single great artery with the long upward course characteristic of the aorta was shown. This great artery could be identified as a persistent truncus arteriosus by the recognition of a branch arising from its ascending part (10 out of 13) or of more than three semilunar valve cusps (5/13). These criteria allowed the correct diagnosis to be reached in 12 of the 13 infants.

Diagnosis, Differential↗
PubMed1978

Echocardiographic identification of aorta and main pulmonary artery in complete transposition.

No completely reliable echocardiographic technique has been described for the separate identification of the aorta and main pulmonary artery in complete transposition of the great arteries. A mechanical wide-angle (60 degrees) sector scanner has been applied to this problem in 17 infants and young children, including 8 newborns before angiocardiography. In all patients a longitudinal scan (saggital section) identified the main pulmonary artery by its directly posterior course immediately beyond the pulmonary valve, and the aorta by its retrosternal course upwards before turning posteriorly above the main pulmonary artery. In addition, a high transverse scan showed the precise spatial relation of the great arteries, and, in 11 of the 17, tilting the scanning plane upwards showed branching of the main pulmonary artery. In 8 infants examined with M-mode echocardiography, an upward sweep from the pulmonary valve showed abrupt termination of the echo from the posterior wall coinciding with the posterior arching of the main pulmonary artery.

Aorta, Thoracic↗
PubMed1977

Hereditary coproporphyria and epilepsy.

A 9-year-old boy with mental deterioration and epilepsy suffered an acute attack of hereditary coproporphyria associated with worsening of seizure control. Leucocyte coproporphyrinogen oxidase activity was undetectable in the patient during this attack, and was reduced in his mother, a latent case. The complex relationship between porphyria, epilepsy, and anticonvulsant drugs is discussed.

Aminolevulinic Acid↗
PubMed1977

Two-dimensional echocardiography with a wide angle (60 degrees) sector scanner.

A wide angle (60 degrees) sector scanner producing a real-time two-dimensional echocardiogram has been used to examine healthy infants, children, and adults. Its method of use is described and findings from longitudinal and transverse scans are presented. The points of difference between the various types of electronic and mechanical two-dimensional scanning systems are discussed. This equipment minimises problems of chest contact and rib and lung interference and, by providing echocardiograms of high line density from a wide angle, is a suitable real-time two-dimensional scanning system for examining patients of all ages.

Adult↗
PubMed1976

Failure of phenobarbitone to prevent febrile convulsions.

One-hundred-sixty-five children without known neurological disorder who presented with their first febrile convulsion between the ages of six months and three years were assigned to daily phenobarbitone treatment or to a control group and followed up at a special clinic for six months. One-hundred-and-sixty-one-one children completed the trial, and of the 88 children assigned to phenobarbitone treatment 10 had further convulsions during this period compared with 14 of the 73 control children. Only 49 of those assigned to phenobarbitone took the drug regularly throughout the trial, and four of these had further febrile convulsions, a proportion not significantly different from that in the controls. All four had mean plasma phenobarbitone concentrations over 69 mumol/l (16 mug/ml) during the trial and in three the plasma concentration was at or over this figure within eight hours over 69 mumol/l (16 mug/ml) during the trial and in three the plasma concentration was at or over this figure within eight hours of the repeat convulsion. Regular phenobarbitone does not seem to prevent febrile convulsions. Attention should instead be directed to organising emergency services to allow early termination of fevrile convulsions, whether first or subsequent, to prevent irreversible brain damage.

Child, Preschool↗
PubMedDate not supplied

Evaluation of pediatric electrocardiogram diagnosis of ventricular hypertrophy by computer program compared with cardiologists.

This study aimed to evaluate the diagnosis of pediatric left ventricular hypertrophy (LVH) and right ventricular hypertrophy (RVH) by the Glasgow electrocardiogram (ECG) interpretation program compared to interpretations provided by two pediatric cardiologists. ECGs had all identifying information removed and were sent to the cardiologists independently with the patient's age and sex and the clinical indication for the ECG, if known. A total of 984 ECGs were included in the study, of which 664 were reported "with clinical indication" and 320 were reported "blind." With respect to an averaged diagnosis of the two cardiologists, the sensitivity of the program for RVH was better when the cardiologists reported blind (73.3%) than with the clinical indication (53.5%), with the same trend for the program compared with individual cardiologists. The specificity of the program was at least 94.4% in all cases. For LVH, the program had high specificity (=95.8%) for "reported blind" and "with clinical indication" cases but low sensitivities throughout (the highest was 44.4% with respect to an averaged diagnosis of the two cardiologists reporting with the clinical indication). Subsequent discussion revealed that if the cardiologists had disagreed with one another initially, their consensus opinion was twice as likely to be in agreement with the program.

Adolescent↗