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Biomedical subjects

Y Kong

Publications and source records attributed to Y Kong.

At least 181 records · Page 10Linked to original sources
PubMed1988

The risk for systemic embolization associated with percutaneous balloon valvuloplasty in adults. A prospective comprehensive evaluation.

STUDY OBJECTIVE: To prospectively investigate the evidence for embolic phenomena associated with percutaneous mitral and aortic valvuloplasty. DESIGN: Prospective, consecutive case series before and after balloon valvuloplasty. SETTING: Referral center hospital and cardiac catheterization laboratory. PATIENTS: Consecutive sample of 32 patients having balloon valvuloplasty for critical symptomatic stenosis of the mitral or aortic valve. Twenty-six patients had aortic stenosis; 6 had mitral stenosis. INTERVENTION: Computed tomography of the head, funduscopy, and electrocardiography were done in all patients before and after valvuloplasty. Cardiac isoenzymes were measured serially in 19 patients. MEASUREMENTS AND MAIN RESULTS: Previous cerebral infarction was seen in nine patients, with three showing a new abnormality after aortic valvuloplasty. In one of these patients a funduscopic hemorrhage was detected by photography. Total creatinine kinase and MB fraction were elevated in 1 of 19 patients. Serial electrocardiograms were unchanged in all patients. CONCLUSIONS: The incidence of cerebral neurologic events and myocardial injury are acceptably low after balloon valvuloplasty of calcific aortic and mitral stenosis. Both episodes of symptomatic cerebral infarction occurred in patients with apparent bicuspid aortic valvular stenosis, suggesting that calcific bicuspid aortic stenosis may be associated with more neurologic events after aortic valvuloplasty.

Adult↗
PubMed1984

Accuracy and interobserver variability of coronary cineangiography: a comparison with postmortem evaluation.

The accuracy of interpretation of coronary cineangiography by two independent observers was tested against postmortem findings in 27 patients who died within 6 months of cardiac catheterization. Variations in cineangiographic interpretations between the angiographers were also evaluated. Two patients had normal coronary arteries, while the remaining 25 patients had significant coronary artery disease. Significant stenosis was defined as 75% or greater reduction in luminal diameter. Of 326 coronary segments that could be evaluated postmortem, 15% could not be evaluated cineangiographically. The respective overall accuracy of the two observers was 89 and 88% with an accuracy of 96 and 100% for the left main coronary artery, 91 and 93% for the left anterior descending artery, 84 and 86% for the right coronary artery and 89 and 79% for the left circumflex coronary artery. Cineangiographic assessment of luminal status distal to a significant proximal lesion was possible in more than 70% of major vessels with accuracy levels of 86% for both observers. Of 96 distal vessels inadequately opacified cineangiographically, 49 (52%) were found to be free of significant lesions. Both angiographers agreed in their assessment of 86% of the 340 coronary segments. Interobserver agreement was significantly better for the left main, right and left anterior descending coronary arteries than for the left circumflex coronary artery (p less than 0.05). Accuracy was 93% for 244 segments that were adequately opacified and assessed the same by both angiographers. Cineangiography can thus be used to evaluate coronary anatomy with a high degree of accuracy and minimal interobserver variability.

Autopsy↗
PubMed1984

Hemorrhagic myocardial infarction after streptokinase treatment for acute coronary thrombosis.

A 37-year-old man with an evolving anterior myocardial infarction received intracoronary thrombolytic therapy six hours after its onset. The restored coronary artery patency was recorded angiographically in the left anterior descending coronary artery (LAD). He died 28 hours after administration of the therapy. Uniform and severe interstitial hemorrhage was present in the area of myocardial necrosis. The distribution of hemorrhage and myocardial necrosis corresponded with the vascular bed of the LAD and was thus consistent with experimental studies that concluded that the hemorrhagic areas were probably confined to muscle that was already necrotic.

Adult↗
PubMed1983

Natural history of patients with single-vessel disease suitable for percutaneous transluminal coronary angioplasty.

To permit comparison of percutaneous transluminal coronary angioplasty (PTCA) with conventional therapy, the clinical outcome was established in patients who would have been suitable candidates for PTCA but who presented before the technique was available. Coronary angiograms were reviewed of patients who met the following criteria: single-vessel disease with proximal subtotal coronary stenosis, chest pain of at least class II, and cardiac catheterization before 1981. Angiograms were evaluated according to established criteria for PTCA by an experienced angiographer. One hundred ten patients (2.1% of the patient population) were judged suitable for PTCA. Clinical and catheterization findings closely resembled those of patients in the national PTCA registry. Five years after catheterization, 97% of PTCA candidates treated medically were alive and 85% had not had myocardial infarction. Forty-six patients had coronary artery bypass surgery within 6 months of catheterization and 10 other patients had subsequent surgery. Five years after surgery, 91% were alive and 87% had not had myocardial infarction. At 6 months of follow-up, 78% of all patients had improved at least 1 functional class, and 86% of all patients working before catheterization were still employed. Functional capacity was well maintained during long-term follow-up (median 6.5 years, range 1.4 to 12.2). These data indicate that PTCA candidates have an excellent prognosis for survival, a low risk of infarction, and well-maintained functional capacity when revascularization is reserved for those with inadequate control of symptoms by medical therapy.

Angioplasty, Balloon↗
PubMed1983

Outcome in one-vessel coronary artery disease.

We analyzed the clinical outcomes in 688 patients with isolated stenosis of one major coronary artery. The survival rate among patients with disease of the right coronary artery (RCA) was higher than that among patients with left anterior descending (LAD) or left circumflex coronary artery (LCA) disease. The survival rate among patients in all three anatomic subgroups exceeded 90% at 5 years. The presence of a lesion proximal to the first septal perforator of the LAD was associated with decreased survival compared with the presence of a more distal lesion. For the entire group of one-vessel disease patients, total ischemic events (death and nonfatal infarction) occurred at similar rates regardless of the anatomic location of the lesion. Left ventricular ejection fraction was the baseline descriptor most strongly associated with survival, and the characteristics of the angina had the strongest relationship with nonfatal myocardial infarction. No differences in survival or total cardiac event rates were found with surgical or nonsurgical therapy. The relief of angina was superior with surgical therapy, although the majority of nonsurgically treated patients had significant relief of angina. The survival rate of patients with one-vessel coronary disease is excellent, and the risk of nonfatal infarction is low. Clinical strategies for the care of these patients must consider the long-term clinical course of one-vessel coronary disease.

Angina Pectoris↗
PubMed1983

Functional improvement of jeopardized myocardium following intracoronary streptokinase infusion in acute myocardial infarction.

The effect of reperfusion on regional left ventricular performance following acute myocardial infarction in man was determined. Intracoronary streptokinase was administered in 24 patients within 6 h of the onset of symptoms. 15 patients (62%) were successfully recanalized during the initial study. Mean percent radial shortening (%RS) in both the jeopardized and compensatory regions were determined using 23 radii from the centroid of diastolic and systolic angiographic silhouettes. Sequential measurements were obtained during repeat cardiac catheterization studies at 24 h in 19 patients and before discharge from the hospital (16 +/- 11 d) in 15 patients. At the time of the predischarge study, each acutely reperfused patient showed improvement in %RS in the jeopardized region (P = 0.01) with 56% returning to the normal range. Despite the uniform improvement in the contractile function of the jeopardized region in each reperfused patient, the global ejection fraction showed no improvement or a decrease at the time of the chronic study in 44%. This was due to a decrease in the compensatory wall motion in the uninvolved segments between the acute and chronic study in each case. Neither the %RS nor the ejection fraction changed significantly at the time of the chronic study in the patients who could not be acutely recanalized. These data indicate (a) significant salvage of jeopardized myocardium associated with recovery of contractile function in patients reperfused during the first 6 h of chest pain following acute myocardial infarction; (b) no improvement in regional or global left ventricular performance in patients who could not be reperfused acutely; and (c) the ejection fraction is strongly influenced by changes in the compensatory wall motion of the uninvolved segments and does not accurately reflect changes in the contractile function of the jeopardized myocardium.

Adult↗
PubMed1983

Clinical value of coronary bypass graft evaluation with CT.

Computed tomography (CT) has a reported accuracy of 45%-97% in assessment of patency of coronary artery bypass grafts. Dynamic CT was done in 26 patients (47 grafts) with recurrent cardiac symptoms after graft surgery. Although CT was 79% accurate (with selective angiography as the standard), the authors do not believe that it provides sufficient information for the assessment of symptomatic patients. Four patients had high-grade stenoses in their grafts, and 50% of patients had significant progression of atherosclerosis in their native coronary arteries. Neither of these conditions could be detected by CT. The clinical contribution of CT will probably be greatest for routine screening of asymptomatic patients soon after operation. Technical problems with CT scanning for graft patency are discussed.

Angiography↗
PubMed1980

The diagnostic and prognostic significance of coronary artery calcification. A report of 800 cases.

The significance of coronary artery calcification was assessed in 800 patients who underwent cardiac fluoroscopy and selective coronary cineangiography. Calcification was shown by fluoroscopy in 250, of whom 236 (94%) had greater than or equal to 75% stenosis of one or more major coronary arteries at angiography. Among patients with significant coronary artery disease, 40% (236/585) had calcification. Patients with calcification demonstrated poorer survival at all follow-up intervals (from six months to five years); the five-year survival rate was 87% for patients without calcification, compared to 58% for those with calcification. The prognostic significance of coronary artery calcification appears to be independent of information obtained by cardiac catheterization and angiocardiography.

Calcinosis↗
PubMed1979

Incidence of mitral valve prolapse in one hundred clinically stable newborn baby girls: an echocardiographic study.

Clinical and echocardiographic examinations were performed on 100 clinically stable, newborn baby girls. Mitral valve prolapse was noted on the echocardiograms of seven babies. Three subjects had systolic clicks, two of whom had systolic murmurs following the click. The four other babies who had echocardiographic evidence of mitral valve prolapse had no abnormal auscultatory signs. Of the 93 babies without evidence of mitral prolapse, 91 had normal echocardiograms and auscultatory features; one was noted to have a murmur consistent with a ventricular septal defect, and another had an eccentric aortic valve on the echocardiogram which was suggestive of a bicuspid aortic valve. Serial studies on our group of subjects will yield useful information regarding the natural history of mitral valve prolapse.

Echocardiography↗
PubMed1979

Regulation of autoimmune response to mouse thyroglobulin: influence of H-2D-end genes.

Studies were initiated to define the H-2-linked genetic control of response to self-determinants of MTg. In addition to the Ir gene control of H-2K end, a modifying effect of D end was seen. The extent of regulation depended upon the derivation of the K-end Ir-Tg gene(s) as well as the D-end genes. When the Ir-Tg gene was from good responder H-2k and H-Ss strains, and the H-2D-end gene from the d allele, antibody levels were moderate to high but cellular infiltration was significantly reduced. These findings demonstrate genetic interaction between I-region and D-end gene products in the response to a self-antigen, MTg.

Alleles↗
PubMed1978

The role of the exercise test in the evaluation of patients for ischemic heart disease.

A cohort of 1472 patients who underwent both exercise stress testing and coronary angiography within six weeks was examined. The data indicated that a combination of exercise parameters is both diagnostically and prognostically important. Almost all patients (greater than 97%) who had positive exercise tests at Stage I or Stage II had significant coronary artery disease. More than half of these (greater than 60%) had three vessel disease and over 25% had significant narrowing (greater than 50%) of the left main coronary artery. Patients who achieved Stage IV or greater exercise durations with either negative or indeterminate ST-segment response had less than a 15% prevalence of three vessel disease and less than a 1% prevalence of left main coronary artery disease. A low risk subgroup (75% of all non-operated patients) was identified with a twelve month survival greater than 99%. A high risk subgroup (11% of all nonoperated patients) was identified with a twelve month survival of less than 85%. The exercise test is a noninvasive, reproducible method to assess the presence and extent of anatomic disease and the prognosis when significant disease has been defined. It should be used in conjunction with other noninvasive tests to determine optimal management in patients evaluated for ischemic heart disease.

Angiocardiography↗
PubMed1978

Type A behavior pattern and coronary atherosclerosis.

Previous research has demonstrated an increased rate of clinical coronary heart disease (CHD) events among people who exhibit a "coronary prone" (Type A) behavior pattern. This study was undertaken to determine whether the association between behavior pattern Type A and CHD might be extended beyond clinical CHD events to include also the coronary atherosclerotic process. In addition to usual clinical evaluation, 156 consecutive patients referred for diagnostic coronary angiography were independently assessed on the basis of a structured interview and assigned a rating of Type A, Type B, or Type X (indeterminate). Traditional physiologic factors--age, sex, cholesterol and cigarette smoking--were found to correlate with atherosclerotic disease. Type A patients were found in increasing proportions among groups of patients with coronary occlusions of moderate to severe degree compared with patients with only mild occlusions. This increasing proportion of Type A patients with increasing disease severity remained significant, even when age, sex, blood pressure, serum cholesterol level and cigarette smoking history were all simultaneously covaried. These findings suggest that, independently of traditional risk factors, behavior pattern Type A may contribute to the risk of clinical CHD events via effects on the atherosclerotic process.

Adolescent↗
PubMed1977

Diagnostic and prognostic significance of electrocardiographic and CPK isoenzyme changes following coronary bypass surgery: correlation with findings at one year.

The incidence of ECG (14 per cent) indication of acute myocardial infarction complicating coronary artery bypass surgery is documented, corroborating the findings of prior series. An additional 32 per cent of patients had appearance of myocardial specific CPK-MB in serum during the immediate postoperative period. All patients surviving to 1 year following surgery (93 of 103) were asked to return for repeat cardiac catheterization to determine the presence and extent of interim ventricular contraction abnormalities. Sixty-five (70 per cent) of the group returned for evaluation. Preoperative and 1 year postoperative left ventriculograms were compared to determine if new contraction abnormalities would confirm the specificity of perioperative QRS and isoenzyme changes, and if the absence of new abnormalities would confirm their sensitivity. The majority of patients (65 per cent) had new areas of asynergy. However, 73 per cent of these were confined to the apex and thus could have been produced by the vent employed during cardiopulmonary bypass. QRS changes were 100 per cent specific and CPK-MB appearance was 78 per cent specific but they were only 20 and 54 per cent sensitive, respectively. Indeed, 46 per cent of those with new asynergy which was non apical had neither QRS change nor CPK-MB appearance. Thus QRS changes were always--and CPK-MB appearance was usually--associated with new asynergy but, in addition, many patients with no perioperative indication of infarction developed new areas of left ventricular contraction abnormality within the first postoperative year.

Angina Pectoris↗
PubMed1977

Ventricular apical vents and postoperative focal contraction abnormalities in patients undergoing coronary artery bypass surgery.

Ventriculograms made 9-15 months after surgery in 48 patients with normal preoperative apical contraction were reviewed to determine the influence of apical venting on apical wall motion in patients undergoing coronary bypass surgery. After interpretation of postoperative apical wall motion, the patients were subdivided into two groups. One group consisted of 34 patients who were vented by inserting a catheter through the apex of the left ventricle and the second group included 14 patients in whom no transventricular vent was made. The two groups were similar clinically and hemodynamically before surgery, and the surgical procedures were similar with the exception of vent site. Following surgery, incidences of graft patency and antegrade flow to the apex were also similar. Nineteen (56%) patients in the apically vented group had apical dyskinesia or akinesia observed on the postoperative ventriculogram while none of the patients who were not apically vented had these findings. None of the patients with apical dyskinesia or akinesia had congestive heart failure following surgery. The postoperative ventriculograms of 12 patients with mitral stenosis who underwent valvulotomy by inserting a Tubbs dilator through the apex were also analyzed. Only one patient (8.5%) had apical dyskinesia or akinesia. Since the patients with mitral stenosis probably did not have significant coronary artery disease, it is possible that the combination of the apical vent and ischemic heart disease was responsible for the focal contraction abnormalities observed.

Cardiac Catheterization↗