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Biomedical subjects

E M Chau

Publications and source records attributed to E M Chau.

17 recordsLinked to original sources
PubMed2001

Severe mitral regurgitation due to mitral valve prolapse associated with Bland-White-Garland syndrome.

Bland-White-Garland syndrome refers to the rare congenital cardiac abnormality whereby the left coronary artery arises from the pulmonary artery. The natural history of this condition is highly variable, ranging from death in early infancy to asymptomatic adult survival. It is sometimes diagnosed in adults with mitral regurgitation thought to be of ischaemic origin. We report a case of a 29-year-old man with Bland-White-Garland syndrome and concomitant mitral valve prolapse, and review the literature on the appropriate investigations and management of this abnormality. Recognition and diagnosis of this condition is important because of the potentially life-threatening complications, which may be prevented by surgical intervention.

Adult↗
PubMed2000

Transcatheter treatment of a case of Lutembacher syndrome.

Lutembacher syndrome refers to the rare combination of congenital atrial septal defect and acquired mitral stenosis. This condition is usually treated by mitral valve operation with concomitant closure of the atrial septal defect. We describe a case of Lutembacher syndrome that was treated successfully with percutaneous transcatheter mitral commissurotomy using the Inoue balloon and closure of the atrial septal defect with the Amplatzer atrial septal defect occluder.

Adult↗
PubMed1997

Nonsecretory immunoglobulin-derived amyloidosis of the heart: diagnosis by immunohistochemistry of the endomyocardium.

Primary amyloid light chain (AL) amyloidosis of the heart is a rare cause of congestive heart failure. Approximately 15% of patients with primary AL amyloidosis demonstrate no monoclonal proteins on serum or urine immunoelectrophoresis:(so-called nonsecretory immunoglobulin-derived amyloidosis). The histologic findings of endomyocardial biopsy from these patients may be indistinguishable from those with senile cardiac amyloidosis. However, the AL type may respond favourably to chemotherapy while the latter type does not. The prognosis is also better in the senile cardiac amyloid type. The precise diagnosis in the present case was made by applying immunohistochemical techniques on cardiac tissues.

Amyloid↗
PubMed1997

Radiofrequency catheter ablation of left-sided accessory pathways using a transeptal technique and specialized long intravascular sheaths. Efficacy, recurrence rate and complications.

49 patients with 51 left-sided accessory pathways underwent radiofrequency catheter ablation for symptomatic supraventricular tachycardia via the transeptal route using specialised long vascular sheaths with compound curves. The procedure was successful in 45 patients (92%). The mean fluroscopic time was 22.5 +/- 15.2 mins and the mean procedure time was 1.7 +/- 0.5 hours. Pericardial tamponade occurred in 2 patients (4%) and 2 patients (4%) required switching to the retrograde transaortic route for successful ablation of the pathways. During the period of follow-up of 16.8 +/- 6.9 months, clinical recurrence occurred in 2 patients (4%). In conclusion, the transeptal route of radiofrequency catheter ablation is a useful alternative strategy to the transaortic approach with good long term results. The use of specialised sheaths may help in stabilisation of the catheter during the procedure which can generate more adequate lesions and consequently a lower recurrence rate.

Adolescent↗
PubMed1997

Mediastinal irradiation for graft-versus-host disease in a heart-lung transplant recipient.

Graft-versus-host disease in solid organ transplantation is very rare, but the prognosis is poor when the condition causes pancytopenia. We report a case of graft-versus-host disease in a heart-lung transplant recipient who at 2 weeks after transplantation had development of features of graft-versus-host disease, including bone marrow aplasia, that could not be attributed to drugs or viral infections. The diagnosis was confirmed by skin biopsy and demonstration of chimerism of peripheral lymphocytes. Augmentation of immunosuppression with intravenous methylprednisolone resulted in improvement in liver function but had no effect on the pancytopenia. Mediastinal irradiation was given with increase in both white blood cell and platelet counts. Unfortunately the patient eventually died of gastrointestinal bleeding and fungemia.

Adult↗
PubMed1996

Predictors of reversibility of pulmonary hypertension in cardiac transplant recipients in the first postoperative year.

BACKGROUND: Pulmonary hypertension remains a risk factor for early postoperative mortality in heart transplantation and may reduce the long-term benefits of the procedure. This study was undertaken to assess the value of baseline hemodynamic studies with nitroprusside used to predict the degree of postoperative reversibility of pulmonary hypertension in cardiac transplant recipients and to identify clinical risk factors for fixed pulmonary hypertension. METHODS AND RESULTS: Hemodynamic data from 55 consecutive patients who underwent orthotopic cardiac transplantation from June 1988 through September 1993 were analyzed. The effects of nitroprusside and transplantation on pulmonary artery pressure, cardiac output, and pulmonary vascular resistance were compared. Multiple regression analysis was used to identify the predictors of reversibility of pulmonary hypertension. Nitroprusside reduced pulmonary vascular resistance by increasing cardiac output and, to a lesser extent, by reducing the transpulmonary gradient. Pulmonary hypertension was less reversible in patients with ischemic heart disease (versus dilated cardiomyopathy) and in former smokers (versus nonsmokers). Patients with nonischemic heart failure and no smoking history had significantly lower posttransplant pulmonary vascular resistance (1.24 +/- 0.45 Wood units) than ischemic patients (who were all former smokers; 2.20 +/- 1.01 wood units) or nonischemic former smokers (1.72 +/- 0.70 Wood units). The correlation of pulmonary vascular resistance during nitroprusside challenge with posttransplant pulmonary vascular resistance was better than that of baseline pulmonary vascular resistance with posttransplant pulmonary vascular resistance. CONCLUSIONS: Nitroprusside testing improves the prediction of late posttransplant pulmonary vascular resistance; hence, it provides data that may be relevant to both early operative risk and later long-term effectiveness of cardiac transplantation. The finding of increased risk of fixed pulmonary hypertension associated with ischemic heart disease and smoking suggests that underlying atherosclerotic vascular disease may contribute to the irreversibility of pulmonary vascular resistance.

Adult↗
PubMed1996

Recurrent aortic valve prosthesis dehiscence secondary to aortoarteritis: three case reports and literature review.

We report three young Chinese male patients who underwent aortic valve replacement for severe aortic regurgitation of subacute onset, complicated by recurrent dehiscence of the aortic valve prosthesis, due to aortitis. One of the three patients underwent aortic valve replacement three times and progression of the prosthesis dehiscence was arrested with the use of corticosteroids. A review of the literature on the prognosis and treatment of aortoarteritis with particular reference to the management of recurrent valvular dehiscence is discussed.

Adult↗
PubMed1994

Ultrasound guided transperineal prostatic aspiration biopsy: experience in Hong Kong.

OBJECTIVE: The purpose of this study is to correlate the result of the ultrasound guided transperineal aspiration biopsy with the clinical findings. MATERIALS AND METHODS: We retrospectively studied 27 patients who had been subjected to ultrasound guided transperineal prostatic aspiration biopsy in our institution during the period 1990 to 1992. The patients were divided into two groups: Group A--those with clinically palpable nodules on digital examination, and Group B--those without palpable nodule but with clinical evidence of prostatic enlargement and/or bladder outlet obstruction. RESULTS: There were 8 biopsy proven cancers, 4 of them were palpable lesions while the other 4 were clinically non-palpable. The overall positive predictive value was 29.6%; this increased to 40% if the lesions were palpable but decreased to 23.5% if the lesions were non-palpable. CONCLUSION: The overall positive predictive value of this technique was found to be consistent with other studies using different methods of biopsies. The positive predictive value was increased if the abnormality was clinically palpable. This technique was also found to be safe and no significant complication was observed in these patients.

Aged↗
PubMed1988

Portal thrombosis complicating appendicitis: ultrasound detection and hepatic computed tomography lobar attenuation alteration.

Lobar attenuation difference of liver on computed tomography was seen in a case of portal pyemia complicating perforated appendicitis. Left portal vein thrombus was detected first by ultrasound and subsequently confirmed by computed tomography. The left lobe of the liver showed greater contrast enhancement during the dynamic computed tomography study. The possible cause of this lobar attenuation difference is discussed.

Adult↗
PubMed1988

Spinal pseudarthrosis complicating ankylosing spondylitis: comparison of CT and conventional tomography.

Pseudarthrosis, a functional false joint, is an important mechanical complication of advanced ankylosing spondylitis. For correct determination of prognosis and therapy, the presence and extent of the abnormality must be assessed accurately. CT findings in 18 patients with 22 pseudarthroses were compared with the results of conventional tomography. The condition was confirmed by surgery in nine patients (50%). CT scans clearly characterized the pseudarthrosis, providing data not provided by conventional tomography in 17 (77%) of the 22 lesions. CT showed irregular diskovertebral osteolysis with reactive sclerosis and more frequently detected the vacuum phenomenon and paraspinal swellings. In all cases, CT showed either a fracture of mobile facet joints in the posterior elements and allowed clear differentiation between the two. In four cases, such differentiation was impossible on conventional tomograms. Associated spinal stenosis was suspected on conventional tomograms in three lesions, but it was shown clearly by CT in 10 lesions. Our results suggest that CT offers considerable advantages over conventional tomography in the investigation of spinal pseudarthrosis complicating ankylosing spondylitis.

Adult↗
PubMed1987

Recurrent pyogenic cholangitis: ultrasound evaluation compared with endoscopic retrograde cholangiopancreatography.

Fifty cases of recurrent pyogenic cholangitis among Chinese in Hong Kong were studied by ultrasound and compared with endoscopic retrograde cholangiopancreatography. The sensitivity of ultrasound detection of both dilated intrahepatic biliary ducts and intrahepatic calculi is 67% as compared with endoscopic retrograde cholangiopancreatography. A negative study, therefore, does not rule out the presence of such pathological features. A dilated common duct is present in virtually every case of recurrent pyogenic cholangitis and ultrasound is very accurate in its detection. Furthermore, ultrasound is able to provide additional information which can be missed with endoscopic retrograde cholangiopancreatography. Prominent periportal echogenicity, concomitant abscesses and tumours are examples in this series. Such findings bear significance on the management of patients with recurrent pyogenic cholangitis.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1986

Prominent periportal echogenicity: its sonographic evaluation and its significance.

Prominent periportal echogenicity was detected during sonographic examination of patients suffering from recurrent pyogenic cholangitis, hepatocellular carcinoma and acute cholecystitis. To document the finding, 140 normal individuals were studied to establish a norm for the evaluation of the periportal echogenicity. The significance of this sonographic finding and its possible aetiology are discussed.

Aged↗
PubMedDate not supplied

Increased incidence of chronotropic incompetence in older donor hearts.

BACKGROUND: Previous Registry studies have reported that heart transplantation with older donor hearts is associated with a more than twofold increase in early mortality. METHODS: An analysis of 77 consecutive patients undergoing heart transplantations at our institution between June 1988 and July 1994 was performed to assess the effect of donor age on mortality and morbidity. Recipients were grouped into those receiving hearts from younger donors (aged < 40 years, n = 60) and those receiving hearts from older donors (aged > 40 years, n = 17). RESULTS: There were two deaths within the first 30 days in the younger donor group and no deaths in the other group. One-year survival rate was 95% and 100% for the "younger" and "older" groups, respectively. The mean recipient age of the younger donor group was lower (46 +/- 14 years) compared with the older donor group (57 +/- 7 years). Morbidity was compared between the two groups; the length of hospital stay (22.6 +/- 15.8 days versus 21.3 +/- 9.4 days), the graft ejection fraction at 1 week (64% +/- 5% versus 62% +/- 7%), and the mean number of rejection episodes within the first 3 months (0.79 versus 0.65) were not statistically different between the two groups. However, the incidence of chronotropic incompetence requiring permanent pacemaker implantation was significantly greater in the group who received older donor hearts (41.2% versus 10.3%, p < 0.05), independent of the ischemic time. CONCLUSIONS: This study shows that older donor hearts may be used safely in selected patients with excellent outcome, although there is an increased incidence of chronotropic incompetence requiring implantation of permanent pacemakers.

Adolescent↗