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Biomedical subjects

G R Sutherland

Publications and source records attributed to G R Sutherland.

At least 397 records · Page 22Linked to original sources
PubMed1990

The assessment of juxtaposed atrial appendages by transoesophageal echocardiography.

As part of a prospective study into the diagnostic role of transoesophageal echocardiography in children with complex congenital heart disease, the atrial morphology was assessed in 62 children. Using the direct visualization of atrial appendage morphology, 58 were shown to have usual atrial arrangement, two were documented to have isomerism of the right and two isomerism of the left appendages. Of those with usual arrangement, four children were demonstrated to have left juxtaposition of the atrial appendages. Only two of these patients were identified during praecordial echocardiographic re-evaluation, and three on angiocardiographic examination. Surgical confirmation was obtained in three, and juxtaposition was excluded in the remaining cases. The transoesophageal cross-sectional imaging features of left juxtaposition of the atrial appendages are unique and readily diagnostic of this entity. They include, first, a lateral deviation of the acid-portion of the atrial septum and, second, a frontal orientation of the antero-superior portion forming the floor and the posterior wall of the junction of the right-sided atrial appendage with the venous component of the atrial cavity. The knowledge of these morphologic characteristics is important, as, otherwise, this malformation may be misinterpreted as representing an atrial septal defect. The results suggest that transoesophageal echocardiography will be the most sensitive preoperative diagnostic technique in detecting or excluding juxtaposed atrial appendages.

Adolescent↗
PubMed1990

The potential value of transoesophageal evaluation of individual pulmonary venous flow after an atrial baffle procedure.

Following a Mustard's procedure, transoesophageal echocardiography allowed the visualization of all 4 pulmonary veins in 7/12 patients (mean age 14.8 years) and of three veins in a further 2 patients. Both upper pulmonary veins could be visualized consistently. No patient had an isolated pulmonary venous stenosis. In 9 patients in sinus rhythm, computer analysis of Doppler tracings from the left upper pulmonary vein showed significantly lower systolic peak velocities (mean 0.39 +/- 0.10 m/s) and time velocity integrals (mean 6.9 +/- 1.66 cm) than in normal subjects (mean 0.6 +/- 0.09 m/s and 14.4 +/- 2.97 cm respectively; P less than 0.001). We postulate that this is due to compromised atrial relaxation and compliance. In contrast, patients in junctional rhythm (mean 10.7 vs. 7.7 cm in normal subjects). Flow reversal during early ventricular systole (due to tricuspid regurgitation or atrial contraction after retrograde conduction during junctional rhythm) was detected in 6/12 patients. These results confirm that the transoesophageal approach should allow the identification of isolated pulmonary venous obstruction after a Mustard procedure. In addition. detailed analysis of tracings of flow in the pulmonary veins can document the presence of compromised atrial relaxation and help to evaluate the severity of tricuspid regurgitation. It may provide a new index with which to assess impaired systemic ventricular function.

Adolescent↗
PubMed1990

Assessment of ventricular septal defect closure by intraoperative epicardial ultrasound.

Intraoperative epicardial two-dimensional echocardiographic imaging, color flow mapping and contrast echocardiography were used in 31 patients after patch closure of a ventricular septal defect to determine their respective values in the assessment of residual shunting after cardiopulmonary bypass and for the prediction of long-term results. Epicardial imaging showed no incidence of patch dehiscence. Residual shunting detected by color flow mapping or contrast echocardiography was graded into one of four categories (0 to III). Real time analysis of color flow mapping studies suggested no shunting (grade 0) in 2 patients, grade I shunting in 20, grade II in 8 and grade III in 1; contrast studies suggested grade 0 in 15, grade I in 6, grade II in 8 and grade III in 2. Interobserver variation in real time encoding of grade I or II shunting was 25% by color flow mapping and 6% by contrast echocardiography. Subsequent frame by frame analysis revealed that both diastolic and early systolic right ventricular turbulence gave rise to false positive results during real time analysis of color flow mapping studies. Color flow mapping allowed exact localization of residual shunting, whereas contrast echocardiography allowed better semiquantification. Postbypass results were correlated in 30 patients with late postoperative precordial studies (mean interval 7.5 months). Persistent shunts were found in 6 (20%) of 30 patients. No patient required reoperation for residual shunting. The predictive value of immediate grade I or II shunting as a marker for persistent long-term shunting was poor, whereas both patients with immediate grade III shunting had shunt persistence, indicating that immediate revision should be considered in such patients. Intraoperative epicardial ultrasound is valuable for the immediate exclusion of important residual shunting after ventricular septal defect closure. Maximal information is obtained when color flow mapping and contrast echocardiography are used in combination.

Cardiopulmonary Bypass↗
PubMed1990

Comparative values of the precordial and transesophageal approaches in the echocardiographic evaluation of atrial baffle function after an atrial correction procedure.

Previous methods used to assess atrial baffle function after correction of transposition of the great arteries have included precordial echocardiography and cardiac catheterization. To evaluate whether single plane transesophageal echocardiography might provide additional information, its findings were correlated with information derived from both precordial echocardiography and cardiac catheterization in 15 patients (14 Mustard procedures, 1 Senning procedure) aged 4.2 to 33 years (mean 16.3). Precordial ultrasound with combined imaging, color flow mapping and pulsed Doppler ultrasound visualized the supramitral portion of the common systemic venous atrium in every case but could identify only superior limb obstruction in three of six patients, mid-baffle obstruction in zero of two and inferior limb obstruction in zero of two patients. Transesophageal studies with use of the same range of ultrasound methods demonstrated superior limb obstruction (severe in four, mild in two) in six of six patients, mid-baffle obstruction in two of two and inferior limb obstruction in two of two patients. The entire pulmonary venous atrium was equally well interrogated by either ultrasound approach, with both identifying three cases (two mild, one moderate) of mid-pulmonary venous atrium obstruction. However, individual pulmonary vein velocity profiles could only be recorded by transesophageal pulsed Doppler ultrasound. Precordial studies identified baffle leaks (1 large, 2 small) in only three patients, whereas transesophageal studies identified 11 such baffle leaks (1 large, 10 small), which were multiple in two patients. It is concluded that transesophageal echocardiography provides a more detailed and accurate assessment of atrial baffle morphology and function than is provided by either precordial ultrasound or cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Comparative value of transthoracic and transesophageal echocardiography in the assessment of congenital abnormalities of the atrioventricular junction.

Information obtained from transthoracic and transesophageal echocardiography (two-dimensional echocardiography with spectral Doppler and color flow imaging) was compared in 17 patients with major congenital abnormalities of the atrioventricular (AV) junction (10 discordant AV connections, 1 criss-cross connection, 5 absent right connections and 1 absent left connection). The findings by either technique were correlated with findings at cardiac catheterization (12 patients) and at surgery (5 patients). In two of six patients with an absent AV connection as defined by transthoracic echocardiography, transesophageal imaging demonstrated an imperforate AV valve. In 11 of 11 patients with a discordant or criss-cross connection, assessment of AV valve and ventricular morphology (by defining the chordal attachments of both AV valves) was possible with transesophageal echocardiography (3 of 11 patients by transthoracic echocardiography); chordal straddling was detected in 1 patient and excluded in 3 others with an associated inlet ventricular septal defect. Anomalous pulmonary venous connection (one patient), atrial septal defect (three patients) and subpulmonary stenosis (five patients) were better assessed by transesophageal imaging, and atrial appendage morphology could be demonstrated in all. The transesophageal technique was less useful in demonstrating the anterior subaortic infundibulum or aortopulmonary shunt (two patients). Although systemic ventricular function could be assessed by either method with use of short-axis M-mode scans, transesophageal pulsed Doppler interrogation of AV valve and pulmonary venous flow patterns provided clues to diastolic dysfunction of the systemic ventricle.

Adolescent↗
PubMed1990

Transesophageal echocardiography in children with congenital heart disease: an initial experience.

Transesophageal echocardiography with a single plane (transverse axis), dedicated pediatric probe was performed prospectively in 25 anesthetized children undergoing routine cardiac catheterization or intracardiac surgery, to assess the potential role of this technique in the initial diagnosis, perioperative management and postoperative follow-up of children with congenital heart disease. The group ranged in age from 1 year to 14.8 years (mean 6.1) and weight from 6.5 to 52 kg (mean 22.4). Studies were successful in all patients and no complications were encountered. The results of the transesophageal studies (combined imaging, color flow mapping and pulsed wave Doppler sampling) were correlated both with the results of prior precordial studies and the information obtained at cardiac catheterization. Transesophageal echocardiography provided a more detailed evaluation of the morphology and function of systemic and pulmonary venous return, the atria, interatrial baffles, atrioventricular valves and the left ventricular outflow tract. Additional information was obtained in 15 patients (60%). Problem areas for single plane transesophageal imaging were the apical interventricular septum, the right ventricular outflow tract and the left pulmonary artery. The intraoperative use of transesophageal echocardiography allowed assessment of the surgical repair and monitoring of ventricular function and volume status while the patient was weaned from cardiopulmonary bypass. Transesophageal echocardiography in pediatric patients is of additional value in three main areas: 1) the precise morphologic diagnosis of congenital heart disease, 2) perioperative monitoring, and 3) postsurgical follow-up.

Cardiac Catheterization↗
PubMed1990

Diagnosis of atrial situs by transesophageal echocardiography.

In a prospective investigation, direct visualization of both atrial appendages was attempted during transesophageal echocardiographic studies in 132 patients with congenital heart disease. High quality cross-sectional images delineating the unique morphologic details of both atrial appendages were obtained in every patient. Abnormal cardiac position such as dextrocardia (four patients) or mesocardia (two patients) did not pose any problems for transesophageal assessment of both atrial appendages. Thus, direct diagnosis of atrial situs was possible in every patient. Atrial situs solitus was present in 127 patients studied. Three patients were found to have situs inversus, one had left atrial isomerism and one had right atrial isomerism. No patient with juxtaposed atrial appendages was encountered. All patients had prior subcostal ultrasound scans for assessment of the morphology and relation of the suprarenal abdominal great vessels and the related patterns of hepatic venous drainage. Patients with abnormal atrial situs had correlative high kilovoltage filter beam radiography for assessment of bronchus morphology. The results of situs determination obtained by either method were in agreement. In this series, transesophageal echocardiography allowed the direct and accurate visualization of both atrial appendages and the determination of atrial situs in all patients studied. Transesophageal echocardiography may prove to be the most reliable in vivo technique for determination of atrial situs.

Abnormalities, Multiple↗
PubMed1990

The human metallothionein gene cluster is not disrupted in myelomonocytic leukemia.

The human metallothionein gene complex on chromosome 16 has been remapped to 16q13 using high-resolution in situ hybridization. The complex is not disrupted by the rearrangement breakpoint on the long arm of chromosome 16 in patients with myelomonocytic leukemia with abnormal eosinophils, as had been previously reported. The locus order on 16q is cen-MT-FRA16B-D16S4-inversion breakpoint-HP-tel.

Blotting, Southern↗
PubMed1990

The value of immediate ultrasound in acute abdominal conditions: a critical appraisal.

A randomized prospective controlled trial was carried out comparing the value of immediate ultrasound examination with conventional management (selective ultrasound examination) in patients with acute abdominal symptoms. Immediate ultrasound led to earlier establishment of a final diagnosis but did not shorten the duration of in-patient care. Selective ultrasound improved diagnostic yield compared to immediate ultrasound and is believed to be the better option. It implies that a prompt but selective ultrasound service should be available for in-patients in the acute specialties.

Abdomen, Acute↗
PubMed1990

Doppler color flow mapping in the diagnosis of ventricular septal rupture and acute mitral regurgitation after myocardial infarction.

Fifty consecutive patients with a newly acquired systolic murmur and severe cardiac decompensation following a recent myocardial infarction (27 with an anterior and 23 with an inferior infarct) were studied by a combination of two-dimensional echocardiography, spectral Doppler and Doppler color flow mapping. The initial ultrasound study defined a ventricular septal rupture in 43 patients and severe isolated mitral regurgitation in 7 patients (5 with papillary muscle rupture and 2 with severe papillary muscle dysfunction). All 50 patients had subsequent confirmation of the diagnosis by either cardiac catheterization or surgical inspection, or both. Two-dimensional echocardiography alone directly visualized a septal defect in only 17 (40%) of the 43 patients with ventricular septal rupture. In all 43 patients the mitral valve appeared normal on imaging. In six of the seven patients with isolated mitral regurgitation, two-dimensional echocardiography correctly demonstrated the structural abnormality of the mitral valve (five with flail anterior leaflet and one with posterior leaflet prolapse). The addition of Doppler color flow mapping greatly improved the diagnostic information in both patient groups. In all 43 patients with ventricular septal rupture, Doppler color flow mapping demonstrated both an area of turbulent transseptal flow and a diagnostic systolic flow disturbance within the right ventricle. In the seven patients with isolated papillary muscle rupture or dysfunction, Doppler color flow mapping not only demonstrated the presence of mitral regurgitation in all cases, but also identified the specific mitral leaflet abnormality by defining the direction of the regurgitant jet.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Comparative roles of intraoperative epicardial and early postoperative transthoracic echocardiography in the assessment of surgical repair of congenital heart defects.

In 94 consecutive patients undergoing surgical repair of congenital heart defects the results of intraoperative (after cardiopulmonary bypass) epicardial two-dimensional and Doppler color flow imaging were compared with those of sequential transthoracic echocardiography performed within 24 h of surgery and again before hospital discharge to define the precise role of intraoperative imaging. In 6 of 7 patients with a residual defect requiring immediate surgical revision, intraoperative imaging correctly identified the defect; spectral Doppler imaging underestimated or did not identify a residual outflow tract gradient in 17 patients. Left atrioventricular (AV) valve regurgitation after repair of complete AV septal defect was underestimated in three patients. Although intraoperative documentation of good ventricular function was usually associated with a good outcome, in three patients poor systemic ventricular function after cardiopulmonary bypass was not associated with early mortality. A minor degree of shunting around the patch was a common finding on epicardial and early postoperative imaging and persisted at the time of hospital discharge in 17 of 46 patients who had undergone patch closure of a ventricular septal defect as part of the surgical procedure. Additional trabecular septal defects were missed on color flow imaging after cardiopulmonary bypass in three patients, one of whom required subsequent reoperation. Although intraoperative two-dimensional and color flow imaging permitted the recognition of the majority of residual defects requiring immediate revision, residual outflow obstruction or AV valve regurgitation was usually underestimated.

Child↗
PubMed1990

The reproducibility of continuous wave Doppler measurements in the assessment of mitral stenosis or mitral prosthetic function: the relative contributions of heart rate, respiration, observer variability and their clinical relevance.

The reproducibility of continuous wave Doppler echocardiographic measurements of transmitral diastolic flow velocity were studied in terms of bias and random error in 40 patients with either mitral stenosis or a Björk-Shiley mitral valve prosthesis. Twenty-seven patients were in sinus rhythm; 13 patients had atrial fibrillation. Intra- and interobserver differences in bias were small for the Doppler parameters studied i.e. early peak velocity (0.6% vs 3.6%), mean diastolic velocity (1.1% vs 8.6%), mean temporal velocity (2.3% vs 14.5%) and pressure half-time (2.7% vs 4.8%). The overall random error of the measurements (in terms of twice the standard deviation) was estimated separately in patients in sinus rhythm and atrial fibrillation: early peak velocity 5.6% and 9.2%, respectively, mean diastolic velocity 9.4% and 22%, mean temporal velocity 8.6% and 19% and pressure half-time 34% and 46%. The relative contributions to the overall random error of observer variation, heart rate dependency and respiratory variation were also studied. Heart rate dependency was demonstrated for both the mean diastolic velocity and the pressure half-time. Respiratory variation was found in the early peak velocity. From the results of this study the number of measurements to reduce the random error of the final average could be determined. Our results indicate that for the measurements in which a respiratory effect is present it is advisable to average the measurements taken over complete respiratory cycles.

Blood Flow Velocity↗
PubMed1990

Diagnostic molecular genetics of the fragile X.

The approaches to carrier detection and prenatal diagnosis of the fragile X syndrome using DNA probes are described. Since the definitive diagnosis rests upon the cytogenetic demonstration of the fragile X, molecular diagnoses are essentially confined to fragile X family members in whom the fragile X cannot be demonstrated. Since none of the polymorphic probes available are tightly linked to the fragile X, the preferred approach is to use probes which flank the fragile site. Useful probes are listed and suggested recombination fractions for use in diagnosis are given. A strategy is outlined for obtaining the closest informative flanking markers with the minimum amount of laboratory effort. Methods of risk analysis are discussed. It is concluded that molecular analysis is very useful for carrier detection but of limited use in prenatal diagnosis.

DNA Probes↗
PubMed1990

The common fragile site in band q27 of the human X chromosome is not coincident with the fragile X.

The common fragile site on the end of the long arm of the human X chromosome has been shown to be at a different location from the rare fragile site which produces the fragile X syndrome of intellectual handicap. The different locations can be clearly seen in chromosomes at about the 550 band level of resolution. This finding should help resolve difficulties in fragile X cytogenetics where expression of the common fragile site can lead to false positive diagnoses.

Chromosome Banding↗
PubMed1990

Three years' diagnostic experience with direct karyotyping of neonatal blood.

Three years' experience with direct karyotyping of cord blood and neonatal venous blood is recorded. Fifty cord blood samples have been processed and 39 yielded satisfactory diagnostic results. Eight of 14 neonatal venous blood samples yielded diagnostic chromosome results after direct karyotyping. Factors which affected success are discussed.

Chromosome Aberrations↗
PubMed1990

Binding of the adenosine A2 receptor ligand [3H]CGS 21680 to human and rat brain: evidence for multiple affinity sites.

A new radiolabeled adenosine receptor agonist, 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamidoadeno sin e (CGS 21680), apparently specific for high-affinity binding sites of the A2 subtype in rat brain, was used to identify and pharmacologically characterize adenosine receptors in human brain. The binding of [3H]CGS 21680, as determined by standard radioligand binding technique in the presence of exogenously added adenosine deaminase, reached equilibrium after 40 min at 25 degrees C. In saturation studies, a single class of high-affinity binding sites with values for KD of 22 +/- 0.5 nM and Bmax of 444 +/- 63 fmol/mg of protein were observed. Similar binding characteristics were observed regardless of whether rapid filtration or centrifugation was used to separate bound versus free ligand. Of the 14 brain regions examined, [3H]CGS 21680 binding was highest in putamen, followed by globus pallidus and caudate nucleus. The level of [3H]CGS 21680 binding in these areas of basal ganglia was identical to 5'-N-[3H]ethylcarboxamidoadenosine ([3H]NECA) binding in the presence of 50 nM N6-cyclopentyladenosine (CPA). The rank order of agonist potencies as determined by a series of competition experiments was NECA greater than or equal to CGS 21680 greater than 2-chloroadenosine greater than N6-(R)-phenylisopropyladenosine greater than N6-cyclohexyladenosine greater than N6-(S)-phenylisopropyladenosine. This potency order was the same for the binding of [3H]CGS 21680 to rat, and of [3H]NECA in the presence of 50 nM CPA to rat and human, brain membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1990

Enhanced morphological diagnosis in infective endocarditis by transoesophageal echocardiography.

Thirty three consecutive patients with clinically suspected endocarditis were studied by both precordial cross sectional echocardiography and transoesophageal echocardiography. The diagnostic value of both techniques was assessed. The data were compared with findings at operation in 25 patients. In 21 patients with native valve endocarditis precordial echocardiography showed evidence of vegetations in six patients and suggested their presence in nine. Transoesophageal echocardiography identified vegetations in 18 patients. Complications were seen in four patients at precordial echocardiography and in nine patients at transoesophageal echocardiography. Precordial echocardiography did not show vegetations in any of the 12 patients with prosthetic valve endocarditis whereas transoesophageal echocardiography showed vegetations in four. Complications were seen in four patients at precordial echocardiography and in 10 at transoesophageal echocardiography. Echocardiographic findings were confirmed at operation in all 25 operated patients. In two patients both echocardiographic techniques had missed the perforation of the cusps of the aortic valve that was seen at operation, but this had no effect on patient management. Transoesophageal echocardiography is the best diagnostic approach when infective endocarditis is suspected in patients with either native or prosthetic valves.

Adolescent↗