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Biomedical subjects

Y L Ko

Publications and source records attributed to Y L Ko.

47 records · Page 3Linked to original sources
PubMed1993

Pericardial color Doppler flow in postpericardiotomy effusive constrictive pericarditis.

A laminar color Doppler flow was discovered in the pericardial space in a 35-year-old man with postpericardiotomy effusive constrictive pericarditis. The flow was detected by transesophageal color Doppler echocardiography. A further pulsed Doppler study revealed a to-and-fro flow, which was synchronized with the cardiac rhythm. We hypothesized that this flow was generated by the rhythmic cardiac contraction. It was then augmented by hard fibrous pericardium and became detectable by color Doppler echocardiography. Pericardial effusion is a frequent echocardiographic finding but little attention has been paid to the flow in it. The laminar flow in the pericardial space in our patient is related to his hard pericardium and can aid in making the diagnosis of effusive constrictive pericarditis. We suggest that flow in the pericardial space deserves more attention and may provide valuable diagnostic aid.

Adult↗
PubMed1993

Infective endocarditis in the transesophageal echocardiographic era.

During a 45-month period, 50 consecutive patients with infective endocarditis were evaluated at the National Taiwan University Hospital with emphasis on the role of transesophageal echocardiography (TEE) in the management of these patients. Among them, rheumatic heart disease was still the most common underlying cardiac disorder (10/50, 20%), while mitral valve prolapse (8/50, 16%) and congenital heart disease (8/50, 16%) were also frequently encountered. More than one third (19/50, 38%) had no underlying heart disease. Four intravenous drug abusers, quite rare previously in Taiwan, were found during the study period. Native valves involved were mostly mitral valve (n = 18), aortic valve (n = 15), and both mitral and aortic valves (n = 3). Tricuspid valve and pulmonic valve were involved in 3 and 2 patients, respectively. Streptococcus viridans was the leading microorganism isolated (21/50, 42%). Staphylococci and enterococci were found in 9 (18%) and 5 (10%) patients, respectively. Twelve patients (24%) were culture-negative in this series. Embolic complications occurred in 13 patients (26%), with a total of 17 episodes. No significant correlation was found between the occurrence of embolization and the vegetation size or the location of the vegetation, if patients with right-sided valvular vegetation and no identifiable vegetation were excluded. Surgery was needed by 25 patients (50%), and mortality occurred in 6 (12%). TEE was superior to transthoracic echocardiography in the detection of vegetations at the mitral or prosthetic valves. Concerning the associated complications with infective endocarditis, TEE was also superior in estimating the severity of mitral regurgitation, recognizing ruptured chordae tendineae and detecting subaortic complications such as valve ring abscess and mitral valve perforation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Reappraisal by transesophageal echocardiography of the significance of left atrial thrombi in the prediction of systemic arterial embolization in rheumatic mitral valve disease.

Systemic arterial embolization imparts a significant risk of serious complications throughout the lives of patients with rheumatic heart disease. Left atrial (LA) thrombi have been thought to be the major source of emboli. A transesophageal echocardiography (TEE) study of 260 consecutive patients with rheumatic mitral valve disease was performed during a period of 24 months, with particular reference to understanding the association between LA thrombi and embolic complications. Of these patients, 155 had predominant mitral stenosis, 24 had significant mitral regurgitation, and the remaining 81 with xenograft mitral valve replacement developed valvular dysfunction (25 resulted in predominant mitral stenosis and 56 in significant mitral regurgitation). LA thrombi were detected in 38 patients (group A) and absent in 222 (group B). Group A patients had a higher frequency of recent (less than or equal to 1 week before TEE study) and remote (greater than 1 week before) embolization than did group B patients (recent: 26.3 vs 5.4% [p less than 0.001]; remote: 18.4 vs 5.0% [p less than 0.01]). The frequency of atrial fibrillation was also greater in group A patients (100 vs 74.3%; p less than 0.001). The exclusion of patients with significant mitral regurgitation and sinus rhythm had no effect on the association between LA thrombi and evidence of previous embolization. It is concluded that TEE is a convenient diagnostic modality that can be used to identify a subset of patients with rheumatic mitral valve disease at high risk for systemic embolization. Consequently, preventive anticoagulation for possible embolic complications should be more vigorously adhered to in patients with rheumatic mitral valve disease and LA thrombi.

Echocardiography↗
PubMed1992

No evidence for linkage of familial hypertrophic cardiomyopathy and chromosome 14q1 locus D14S26 in a Chinese family: evidence for genetic heterogeneity.

To understand the molecular basis of familial hypertrophic cardiomyopathy (FHC) in the Chinese population, a family with FHC was investigated. Nineteen family members who were 16 years of age or older were examined by M-mode or two-dimensional echocardiography. Eight members were diagnosed to be affected echocardiographically or clinically. Lymphocytes isolated from 20 family members were successfully transformed into permanent lymphoblastoid cell lines by Epstein-Barr virus. Three genomic DNA probes (CRI-L436, CRI-L329, and pSC14) that were derived from chromosome 14q1 loci and demonstrated to be linked closely to FHC were used to probe this family. Using the techniques of restriction fragment length polymorphism (RFLP) and linkage analysis, the probe CRI-L436, which recognized locus D14S26, was found informative in this family. The lod scores were -2.0 at theta = 0.025 and -1.49 at theta = 0.05. Thus, there was no evidence of linkage between the locus D14S26 and the gene for FHC in the pedigree studied. In addition, polymerase chain reaction (PCR) amplification did not indicate a mutation on exon 13 of the beta cardiac myosin heavy chain gene as previously reported. Our data suggest that FHC is a genetically heterogeneous disease.

Adult↗
PubMed1992

Idiopathic hypertrophic cardiomyopathy in identical twins. Morphological heterogeneity of the left ventricle.

We report a pair of identical twins with HC with varying extent of left ventricular hypertrophy and some degree of left ventricular outflow tract obstruction. The diagnosis of identical twins was based on the same sex, blood typings, HLA typings and hybridization patterns to four hypervariable DNA probes. Identical twins are derived from a single zygote and are genetically homogeneous human beings. The present report suggests that heterogeneity in the morphologic expression of HC may not be solely attributed to genetic factors. Environmental factors also may play an important role.

Adult↗
PubMed1992

Metastasis of hepatocellular carcinoma to the heart: unusual patterns in three cases with antemortem diagnosis.

Unusual patterns of cardiac metastasis were noted in three cases of hepatocellular carcinoma (HCC): one patient was noted to have a large right ventricular (RV) tumor mass with intracavitary growth and myocardial invasion; the second had massive pulmonary and left atrial (LA) metastasis; and the third patient had a right atrial tumor mass with concomitant RV and LA involvement. Tumor implantation to the RV without right atrial involvement and extensive myocardial invasion is unusual in HCC. The LA involvement is probably related to tumor growth from the pulmonary veins following massive metastasis to the lung, direct invasion of the atrial septum or tumor implantation via a subclinical right-to-left shunt through the patent foramen ovale. To the best of our knowledge, such unusual intracavitary metastases in HCC have not been reported previously. Cardiac metastasis, without local gross recurrence, may be one of the presentations after lobectomy in patients with HCC.

Adult↗
PubMed1992

Inheritance of hypertrophic cardiomyopathy in Chinese--M-mode and two-dimensional echocardiographic analysis of 28 families.

To determine the mode of inheritance and degree of penetrance of hypertrophic cardiomyopathy (HC) in Chinese, 132 family members of 28 probands with HC were assessed by M-mode and two-dimensional echocardiography. Of these 132, 103 cases were first-degree relatives of the probands. Twenty-seven (20.4%) family members, including 19 cases of first-degree relatives of the probands, had HC. Familial occurrence of HC was noted in 13 (46.4%) families. In 10 families, the affected relatives were identified in successive generations, and the mode of inheritance was most consistent with an autosomal dominant trait. The frequency with which HC was identified in relatives increased significantly with the number of subjects studied and a positive family history of sudden death. Subgroup analysis, using multivariate logistic regression analysis, revealed that increasing age was independently associated with a higher frequency of definite cases in first-degree relatives of the probands. In contrast, by multivariate analysis, there were no significant differences between frequency of definite cases in female and male relatives or in different familial relationships (parent, sibling, offspring) to the probands.

Adolescent↗
PubMed1989

Retrospective analysis of 97 patients with infective endocarditis seen over the past 8 years.

The medical records of 97 consecutive patients (101 episodes) of infective endocarditis seen from January 1979 through January 1987 were reviewed. Only 30% of the patients were over 50 years of age and the majority (69%) of infecting organisms were streptococci (mainly of the viridans group), which were similar to those reported from the West in the early antibiotic era. Pseudomonas organisms and enterococci accounted for 6% and 5%, respectively. Fungal infections were noted in 2 patients. There was a high incidence (38%) of predisposing rheumatic valvular disease; approximately half of these patients had prosthetic valve infections. Mitral valve prolapse was also an important predisposing disease (11%). One-third (34%) of the patients had febrile illness for longer than 8 weeks before the diagnosis was established. The hospital morality rate was 22%; cerebral embolism and ruptured mycotic aneurysm, congestive heart failure, and sudden death were the major causes of death. Echocardiography disclosed vegetations on the cardiac valves and preexisting lesions in 75% of the episodes. Early recognition and proper treatment should be the focus of efforts to reduce mortality from infective endocarditis.

Adolescent↗