Quantative Analysis of Mitral Valvular Calcification in Mitral Stenosis

BACKGROUND: Conventional echocardiography provides fundamental information about mitral valve morphology and function but is often subjective and has a relatively low specificity in evaluating valve calcific deposit, which is critical information for the preoperative decision. We hypothesized that mitral valvular calcification could be detected in standard two-dimensional echocardiograms of mitral valve in vivo by evaluating regional gray level(echo amplitude) using computerized image analysis so that we could overcome the subjectivity and low specificity of conventional echocardiography. METHODS: We tested this hypothesis by performing standard 2.5MHz two-dimensional echoes on mitral valve and myocardium in 30 patients with mitral stenosis, scheduled to undergo mitral valve replacement. We compared gray level of each region of interest in mitral valve and myocardium in stop-frame images with the degree of calcifications identified by pathologic and radiographic examinations. RESULTS: Ratio of mean gray level of mitral valve to mean gray level of myocardium was the most reliable value in evaluating degree of calcification. Quantitatively, region of calcification displayed the ratio of significantly higher value than that of no calcification. In case of anterior mitral valve, the ratio of the evident calcified region was greater than 3.11, that of the region without calcification was less than 2.42 and that of microcalcification was betwwn 2.42 and 3.11. For posterior mitral valve, the ratio of the evident calcified region was greater than 3.50, that of the region without calcification was less than 2.19 and that of microcalcification was between 2.19 and 3.50. The sensitivity and specificity of this method for assessment of degree of calcification was 75% and 100% for anterior mitral valve and 9% and 87.5% for posterior mitral valve. CONCLUSION: Mitral valvular calcification could be detected quantitatively in standard two dimensional echocardiograms of mitral valve in vivo by evaluating regional gray level(echo amplitude) using computerized image analysis.

Transcatheter Closure of Patent Ductus Arteriosus in Adults

BACKGROUND: Transcatheter closure of patent ductus arteriosus, using the Rashkind double umbrella occluder system, had been attempted in mulitcenter since non-surgical closure of patent ductus arteriosus by Rashkind. METHODS: Between July 1991 and June 1993, transcatheter closure of patent ductus arterious was attempted in 20 adult patients(21 trials). RESULTS: Seventeen female and 3 male patients was consisted of the study. The patient age ranged from 17 to 54 years(mean 30+/-9 years). Mean pulmonary artery pressure before closure was 18.5+/-6.0mmHg(range from 10mmHg to 30mmHg). The diameter of ductus ranged from 3.5mm to 8.0mm(mean 5.2+/-1.5mm), as determined by contrast injection through 11F Mullin sheath or 7F catheter. There was significant decrease of Qp/Qs from 2.6+/-1.1 to 1.5+/-0.4 immediately after transcatheter closure of ductus(p<0.01). There was significant decrease of left ventricular end-diastolic dimension by echocardiogram from 58.7+/-7.6mm to 53.6+/-6.5mm after transcatheter closure of ductus(p<0.01). Among the 21 cases, 16 cases(76.2%) had the clinical improvement without the support of surgical closure. One 17mm Rashkind umbrella was retrieved because of position and problem of deployment. There was no device embolic experience in 21 cases. There were 2 cases of hemolytic anemia during the follow-up period ; one case was surgically ligated and another 17mm device was implanted in the other case. CONCLUSIONS: Transcatheter closure of patent ductus arteriosus in adult patients can replace the surgical correction in selected patients.

Chronic Total Obstruction of Left Main Coronary Artery: Report of Five Patients and Review of Published Reports

BACKGROUND: Total obstruction of the left main coronary artery is a common cause of sudden death but is rarely seen in patients who survive to undergo diagnostic evaluation or treatment. METHODS: During twenty six-year period, we encountered 5 patients with chronic total obstruction of the left main coronary artery out of about 4,000 patients who underwent coronary angiography. RESULTS: All patients have undergone coronary bypass surgery. These patients present with increasingly severe angina. A right dominat coronary anatomy is always found, usually with well-developed right-to-left collaterals. Left ventricular function was severely impaired in two patients out of five patients. CONCLUSIONS: The results of surgical revascularization in our patients and others described in the literature can support the safety and efficacy of this approach.