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Biomedical subjects

W G Daniel

Publications and source records attributed to W G Daniel.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Pregnancy and congenital heart failure].

While in the past, rheumatic heart disease accounted for the largest number of pregnant women with heart disease, the incidence has declined over the years. On the other hand, because of advances in medical treatment and surgical management, the ratio of adolescent females with congenital heart disease increased significantly during the last decade. Pregnancy is associated with many physiologic adjustments such as changes in blood volume, stroke volume, and cardiac output, and may result in deleterious clinical effects in patients with congenital heart disease. Although a good outcome for these women can often be expected, congenital heart disease still presents a high-risk pregnancy involving both mother and infant. The actual risk depends on the type of malformation and functional impairment of the mother. To bring these women safely through pregnancy, a strong cooperation between pediatric and adult cardiologists, obstetrician, and other physicians is necessary.

Female↗
PubMed1993

[Pulmonary thromboembolism in antiphospholipid syndrome].

A 37-year-old woman in acute right heart failure had experienced systemic venous thromboses for 17 years, five miscarriages and repeated pulmonary emboli. For the last 7 years she had been treated symptomatically for pulmonary hypertension. The platelet count was 62,000/microliters, thromboplastin time under phenprocoumon was 22%, partial thromboplastin time was 72 s. Despite anticoagulation with phenprocoumon and heparin (7,500 IU two times daily subcutaneously) new pulmonary emboli occurred and platelet count fell to 12,000/microliters. An increased titre for anticardiolipin antibodies (IgG > 320 GPL U/l, IgM 8 MPL U/l), antinuclear (1:640) and anti-ds-DNA antibodies (> 200 IU/ml) with simultaneous complement consumption suggested secondary antiphospholipid syndrome associated with lupus erythematodes. Treatment with prednisolone (150 mg/d), immunoglobulins (20 mg/d intravenously for 5 days) and heparin (25,000 IU/24 h intravenously) achieved an increase in platelet count to 200,000/microliters within 10 days, but fell again when the prednisolone dose was reduced, recovering under azathioprine, 150 mg/d. Four weeks later the patient died of renewed acute right heart failure.

Acute Disease↗
PubMed1993

Comparison of transthoracic and transesophageal echocardiography for detection of abnormalities of prosthetic and bioprosthetic valves in the mitral and aortic positions.

Two-dimensional echocardiography is the diagnostic procedure of choice for evaluation of prosthetic valve abnormalities. However, transthoracic echocardiography (TTE) may be limited owing to acoustic shadowing and poor acoustic windows. Some of these limitations may be overcome by transesophageal echocardiography (TEE). One hundred twenty-six patients with 148 prosthetic valves (113 bioprostheses and 35 mechanical devices) were studied by M-mode and 2-dimensional TTE and TEE. Prosthetic valve morphology was confirmed by surgery or autopsy in all cases; 124 prostheses were classified as diseased (33 endocarditis, 8 thrombi, and 83 degeneration defined as leaflet thickening > 3 mm with restricted motion) and 24 as normal. Prosthetic valve endocarditis and thrombi were correctly identified by TTE in 12 of 33 (36%) and 1 of 8 (13%) prostheses, respectively, but could be diagnosed by TEE in 27 of 33 (82%; p < 0.001) and 8 of 8 (100%; p < 0.01), respectively. Compared with TTE, TEE had a higher sensitivity for morphologic prosthetic valve abnormalities in patients with either bioprostheses (88 [87%] vs 66 [65%] of 101 prostheses; p < 0.01) or mechanical devices (19 [83%] vs 5 [22%] of 23 prostheses; p < 0.01) and in patients with a prosthesis in either the aortic (49 [77%] vs 32 [50%] of 64; p < 0.01) or mitral (58 [97%] vs 39 [65%] of 60; p < 0.001) position. Overall, sensitivity and specificity were 57 and 63%, respectively, for TTE, and 86 and 88%, respectively, for TEE.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1993

Diagnosis of heart tumours by transoesophageal echocardiography: a multicentre study in 154 patients. European Cooperative Study Group.

In a retrospective multicentre study, the diagnostic potential of transoesophageal 2D-echocardiography (TEE) as compared to precordial 2D-echocardiography (TTE) was determined in 154 patients with primary or secondary tumours of the heart. Additionally, the value of standard diagnostic parameters, such as symptoms, X-ray of the chest and electrocardiogram were evaluated. In 84 patients (24 male, 60 female; age 20-85, mean 56.6 years) intracardial tumours were present, and 70 patients (37 male, 33 female; age 18-79, mean 44.3 years) presented with peri- or paracardial tumours. The main symptoms of patients with intracardial tumours were dyspnoea (60.7%), vena cava syndrome (22.2%) and chest pain (20.2%). Embolization was found in 11.9%. Left or right atrial enlargement was observed on chest X-ray in 23 patients, and echocardiographic abnormalities in 17 cases. The patients with peri- or paracardial tumours presented with dyspnoea in 51.4% of cases, loss in body weight in 20.0% and with vena cava syndrome and chest pain in 17.1%. The chest X-ray was abnormal in 56 patients. Unspecific ST segment changes in the electrocardiogram were observed in five, and arrhythmias in seven cases. Diagnosis of atrial myxomas was achieved by TTE in 95.2%, by TEE in 100%, by angiography in 78.4%, by computed tomography (CT) or magnetic resonance tomography (NMR) in 70%. Identification of the attachment point was made by angiography in 8.1%, by TTE in 64.5% and by TEE in 95.2%. In 22 patients with intracardial tumours (myxomas excepted) diagnosis was achieved by TTE in 90.9%, by TEE in 100%, by CT or NMR in 88.9% and by angiography in 50%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The role of transesophageal echocardiography in the detection of left atrial thrombi.

Sensitivity of transthoracic echocardiography in the detection of left atrial thrombi, in particular thrombi confined to the left atrial appendage, is surprisingly low (33%-72%). Concerning the detection of left atrial thrombi, transthoracic echocardiography appears as an inadequate technique in patients with suspected cardiogenic embolism with a success rate of only 0.8% in earlier, and about 3% in recent studies. Imaging from the esophagus substantially increases the detection rate for left atrial thrombi, and is the only clinically relevant semiinvasive technique to diagnose thrombi confined to the left atrial appendage. Transesophageal echocardiography has markedly increased the diagnostic power of cardiovascular ultrasound in patients with suspected cardiogenic embolism and/or atrial fibrillation. Meta-analysis of pooled studies using the transesophageal approach in these patients revealed thrombi within the left atrial cavity in about 7% and within the atrial appendage in about 12% of cases.

Coronary Thrombosis↗
PubMed1993

[Value of transesophageal echocardiography in diagnosis of diseases of native heart valves].

In the clinical management of patients with valvular heart disease, transthoracic echocardiography (TTE) combined with Doppler has become the central diagnostic tool during the past decades. The development of transesophageal echocardiography (TEE) has led to an improved image quality especially of structures distant to the chest wall. However, since TEE is a semi-invasive technique, its use has to be considered carefully. In aortic valve disease, TEE facilitates a detailed study of valve morphology and allows sufficiently reliable planimetry of aortic valve area, at least when the multiplane approach is used. This is particularly helpful in those patients where Doppler interrogation from precordial windows fails. Aortic regurgitation is diagnosed more frequently by TEE color-flow imaging than by TTE; however, both techniques allow only semiquantitative assessment of the severity of regurgitation. TEE is also superior to TTE in defining the exact origin site, number and configuration of regurgitant jets in patients with mitral insufficiency. In particular minimal and mild mitral regurgitation is more easily detected by TEE than by TTE. The same is true for flail mitral leaflets, chordal and papillary muscle rupture, and potentially also for discrete forms of mitral valve prolapse. During surgery, TEE can be considered as an ideal tool for immediate assessment of the results of mitral valve reconstruction. Calculation of pressure gradients and valve area by TEE Doppler analysis shows comparable results to precordial studies. When multiplane TEE is available, Doppler beam alignment may become even improved in selected cases with severely excentric flow jet orientation. In addition, TEE provides of course clinically important information concerning presence or absence of atrial and particularly atrial appendage thrombi as well as of spontaneous echo contrast in patients with stenotic mitral valve. This is not only helpful regarding the decision for anticoagulation but it may also be critical in the selection of candidates for percutaneous mitral balloon valvuloplasty. TEE does also allow the morphological and functional evaluation of tricuspid and pulmonic valves. In this context, the use of biplane or multiplane TEE probes is superior to that of monoplane devices. However, currently available data does not provide unequivocal evidence that the analysis of tricuspid and pulmonic valve disease by TEE is superior to the conventional transthoracic approach.

Blood Flow Velocity↗
PubMed1993

[The value of echocardiography in diagnosis of acute pulmonary embolism].

The technology of echocardiographic imaging is now widely available and has become increasingly important in the diagnosis of severe pulmonary embolism. In this setting transthoracic two-dimensional echocardiography (TTE) permits a rapid and non-invasive bed-side assessment of right ventricular size and systolic function. Doppler techniques facilitate precise measurements of pulmonary arterial pressures. These parameters can be easily followed after initiating therapy and allow to recognize patients refractory to the chosen therapeutic regimen. With transesophageal echocardiography (TEE), as well as with TTE, direct visualization of thromboembolic material within the central pulmonary arteries or the right heart chambers is possible. TEE, however, is more sensitive than TTE in detecting thrombotic or embolic material. It is also superior in the diagnosis of a patent foramen ovale which may indicate impending paradoxical embolism. The role of intravascular ultrasound imaging in clinical practice is not clear yet. It may be helpful in the localization and differential diagnosis of thromboembolic material in the pulmonary vascular bed.

Acute Disease↗
PubMed1993

[Imaging of a congenital coronary fistula using biplane transesophageal color-coded echocardiography. A case report].

A case report of a congenital coronary artery fistula between left main stem and pulmonary artery is presented. This fistula was not detectable by conventional transthoracic color-Doppler echocardiography. In contrast, precise localization of origin and site of drainage of this fistula could be demonstrated by biplane transesophageal color-Doppler echocardiography. Subsequent coronary angiography confirmed the echocardiographic findings.

Adult↗
PubMed1992

Diagnosis of patent foramen ovale by transesophageal echocardiography and association with cerebral and peripheral embolic events.

This study compares the value of transthoracic (TTE) and transesophageal (TEE) color Doppler and contrast echocardiography for detecting a patent foramen ovale (PFO). A total of 238 patients were studied: 74 patients with a history of otherwise unexplained ischemic stroke, transient cerebral ischemic attacks or peripheral embolic events (group A), 48 with a history of similar episodes explained by other cardiac abnormalities (group B), and 116 with no embolic events (group C). A PFO was detected by contrast TEE in 50 of 238 patients (21%) compared with 45 patients (19%) by color Doppler TTE. In a subgroup of 198 patients, TEE results could be compared with TTE findings. No patient had a PFO identified by color Doppler TTE. Contrast TTE detected a PFO in 15 patients (8%) compared with contrast TEE which demonstrated a PFO in 44 of 198 patients (22%) (p less than 0.001). Prevalence of PFO by TEE was 22, 21 and 22% in groups A, B and C, respectively. A PFO was present in 50% of patients aged less than 40 years and otherwise unexplained ischemic stroke; this percentage was higher (p less than 0.05) than corresponding values found in all other groups. Thus, contrast and color Doppler TEE are significantly superior to TTE for detecting PFO. The prevalence of PFO is significantly increased in young adults with otherwise unexplained ischemic stroke.

Brain Ischemia↗
PubMed1992

Colour Doppler ultrasound assessment of arteriovenous haemodialysis fistulas.

Satisfactory function of the arteriovenous fistula (AVF) is essential for adequate haemodialysis in patients with chronic renal failure. Existing methods to assess AVF function are imprecise (eg, clinical examination) or invasive (eg, angiography). We assessed the value of colour flow-doppler ultrasound (CFDU) in the investigation of clinically suspected AVF dysfunction. 51 patients with suspected impairment of AVF function were studied by CFDU, and 28 also underwent angiography. The findings were compared with the reference standard of the findings at reoperation. CFDU showed AVF stenoses in 18 patients, which were all confirmed at reoperation; the results of angiography in 13 of these 18 patients showed complete agreement with the findings of CFDU and surgery. CFDU showed partial or complete AVF thrombosis in 33 patients, confirmed in all patients at reoperation; 15 patients also underwent angiography, and thrombi were not found in 6 (in 4 because of technical failure). 7 patients had aneurysms on CFDU that were confirmed by surgery in all patients and by angiography in 2 of the 3 patients studied. CFDU enables reliable non-invasive assessment of AVF morphology and function and may become the procedure of choice for AVF assessment in patients with suspected AVF abnormalities.

Adult↗
PubMed1992

Imaging of pulmonary artery and vein anastomoses by transesophageal echocardiography after lung transplantation.

BACKGROUND: In patients after isolated lung transplantation, the postoperative course may be complicated by dysfunction of the pulmonary artery and vein anastomoses. METHODS AND RESULTS: Pulmonary artery and vein anastomoses in 11 transplanted lungs (four left, four right, and three bilateral lungs) in 10 patients were studied 1 day to 11 months after operation by transesophageal echocardiography (TEE). All 14 pulmonary vein anastomoses, all seven right (100%) and five of seven (71%) left pulmonary artery anastomoses could be visualized by TEE. Thrombosis of a left pulmonary vein anastomosis could be identified by TEE and successfully treated by thrombolysis. TEE detected a significant stenosis in one right and one left pulmonary artery anastomosis; anastomoses dysfunction were confirmed by cardiac catheterization and pulmonary angiography and successfully treated by surgical correction in both cases. CONCLUSIONS: Function and morphology of pulmonary artery and vein anastomoses in patients after isolated lung transplantation can reliably be assessed by TEE. In patients with suspected dysfunction of an anastomosis, TEE may be considered the diagnostic technique of choice.

Adult↗