Biomedical subjects

J W Ha

Publications and source records attributed to J W Ha.

42 records · Page 3Linked to original sources

PubMed1996

Real-time determination of left ventricular ejection fraction by automatic boundary detection in patients with dilated cardiomyopathy: a comparison with radionuclide ventriculography.

Echocardiographic automatic boundary detection (ABD) is a new on-line technique which automatically outlines the left ventricular endocardial border and instantly calculates the left ventricular area and volume from two dimensional echocardiographic images. To determine if left ventricular ejection fraction (LVEF) can be derived using the ABD method, 25 consecutive patients with dilated cardiomyopathy, aged 52.1 +/- 15.2 (range 14 approximately 75), underwent complete echocardiographic examination with both the ABD method and radionuclide ventriculography (RVG). End-diastolic and end-systolic left ventricular areas were obtained on-line from the apical four chamber view. Left ventricular length was also measured from an apical view. Left ventricular volumes and ejection fraction were calculated using the single plane area-length method. ABD measurements could be obtained in all patients. Linear regression analysis compared ejection fraction derived by ABD and RVG. The mean radionuclide LVEF was 20.9 +/- 6.8% and mean ABD-derived LVEF was 22.7 +/- 5.8%. Linear regression analysis revealed that the ABD-derived LVEF is closely correlated with the RVG-derived LVEF (r = 0.87, p < 0.001). In conclusion, ABD echocardiography is a new on-line technique which may be used to accurately calculate LVEF in patients with dilated cardiomyopathy.

Adolescent↗

PubMed1994

Collateral circulation in total occlusion of the left anterior descending or right coronary artery.

The functional significance of the collateral circulation was evaluated in 125 patients with total coronary occlusion. Patients were classified into two groups. Group 1:patients with angina pectoris (AP), Group 2:patients with a first transmural myocardial infarction (MI) within 3 months of the symptom onset. Clinical variables, resting and exercise electrocardiogram (EKG) were analyzed with angiographic findings. Collateral fillings were graded from 0 to 3: 0 = none; 1 = filling of side branches only; 2 = partial filling of the epicardial segment; 3 = complete filling of epicardial segment. The wall motion of each segment was scored from 1 to 5: 1 = normal; 2 = mild to moderate hypokinesia; 3 = severe hypokinesia; 4 = akinesia; 5 = dyskinesia. The scores of the 5 segments were added to yield a total LV score. There was a higher prevalence of good collaterals and multi-vessel disease in patients with AP than in those with MI (83% vs 53%, 54% vs 30%, respectively, p < 0.005). The left ventricular ejection fraction (LVEF), left ventricular end-diastolic pressure (LVEDP) and segmental wall motion score were significantly better in patients with AP than in those with MI (68.9 +/- 13.4%, vs 50.5 +/- 12.6%, 15.0 +/- 7.3 mmHg vs 20.3 +/- 8.8 mmHg, 6.5 +/- 2.2 vs 9.6 +/- 2.3, respectively, p < 0.05). In spite of total coronary occlusion, 61% of AP patients had normal resting EKG but (96% of AP patients who underwent treadmill test proved positive. The proportions of well-developed collaterals in 3 groups divided according to the interval between onset of MI and angiography (within 1 day, 2 to 14 days, 15 days to 3 months) were 13%, 54% and 60%. There were no significant differences in LVEF, segmental wall motion score and LVEDP in MI patients with poorly-developed collaterals and well-developed collaterals (49.1 +/- 15.7% vs 46.4 +/- 10.1%, 11.1 +/- 2.2 vs 10.9 +/- 1.4 and 24.3 +/- 9.7 mmHg vs 20.3 +/- 7.0 mmHg, p = NS). The degree of collateral development was higher in MI with right coronary artery occlusion compared with that of left anterior descending artery occlusion (1.1 +/- 1.0 vs 2.0 +/- 1.0, p < 0.05). In conclusion, collateral circulation can prevent myocardial ischemia and preserve myocardial function in a significant number of patients with AP but do not provide protection against exercise-induced myocardial ischemia in the majority of patients with AP.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1994

Initial clinical experience of intracoronary coil (Gianturco-Roubin) stents for management of acute dissection after balloon angioplasty.

Dissections after percutaneous transluminal coronary angioplasty (PTCA) are risk factors for acute or subacute vessel closures. Intracoronary stenting was developed to avoid these complications by pressing the intimal and medial flaps against the vessel wall, thus reducing the risk of acute closure from thrombus formation. Thirty three coil (Gianturco-Roubin) stents were implanted into the coronary arteries of 32 patients with dissections after PTCA during the period of March 1993 to December 1993. The indications for stent implantation were acute closure in 6 (18.8%), threatened closure in 6 (18.8%) and suboptimal result in 20 (62.4%) patients. Stent insertion were successful in 30 (94%) patients. The diameter stenosis in an immediate angiographic findings after stenting was decreased from 87% to 18% by caliper estimation. Emergency coronary artery bypass graft surgery was required in 1 (3%) patient. A non-Q wave myocardial infarction occurred in 1 (3%) patient. Complications included hematoma of the arterial access site requiring blood transfusion in 4 (12.5%) patients and hemopericardium in 1 (3%) patient. Our initial clinical experience of flexible coil coronary stent imply that stenting is efficacious treatment for acute dissections that are causing acute or threatened closure following angioplasty. The long term follow-up result in all groups of patient who received coronary stents is needed for better evaluation of new devices and prognosis.

Acute Disease↗

PubMed1993

Percutaneous mitral balloon valvuloplasty in patients with restenosis after surgical commissurotomy: a comparative study.

We performed percutaneous mitral balloon valvuloplasty (PMV) in 367 patients to compare the effectiveness of PMV between patients with mitral restenosis after surgical commissurotomy (group 1) and patients with unoperated mitral stenosis (group 2). Twenty-two had undergone closed or open mitral commissurotomy 11.2 years before. There were no significant differences in clinical profiles between the two groups. The mitral valve area was increased from 1.0 +/- 0.8 to 1.8 +/- 0.6 cm2 in group 1 and 0.9 +/- 0.3 to 2.0 +/- 0.7 cm2 in group 2 (p > 0.05). The mitral gradient was decreased from 14 +/- 5.9 to 6 +/- 2.6 mmHg in group 1 and 18 +/- 7.0 to 7 +/- 5.3 mmHg in group 2 (p > 0.05). The increment of mitral regurgitation and significant left to right shunt after PMV were not significantly different (10% versus 14.7%, 5% versus 10.4% respectively). Optimal results were attained in 75% of the patients in group 1 and in 84.3% of the patients in group 2 (p > 0.05). These results suggest PMV in mitral restenosis after surgical commissurotomy may be safe in selected patients and may be equally effective as in unoperated mitral stenosis.

Adult↗

PubMed1993

Cardiovascular findings of Hutchinson-Gilford syndrome--a Doppler and two-dimensional echocardiographic study.

Progeria, also known as Hutchinson-Gilford syndrome, is an extremely rare condition originally described by Hutchinson in 1886. Death results from cardiac complications in the majority of cases and usually occurs at an average age of fourteen years. We recently experienced a patient with progeria who died suddenly after symptomatic improvement with conservative treatment. A Doppler and two-dimensional echocardiographic study revealed an enlarged and hypertrophied left ventricle with reduced global systolic function and senile aortic calcific stenosis (peak systolic pressure gradient: 50 mmHg) with a moderate degree of aortic regurgitation. Doppler findings of restrictive hemodynamic suggest severe left ventricular dysfunction due to multiple influences from the aging process, coronary artery and valvular heart disease.

Adult↗

PubMedDate not supplied

123I-MIBG myocardial scintigraphy as a noninvasive screen for the diagnosis of coronary artery spasm.

BACKGROUND: It has been suggested that the sympathetic nervous system might play an important role in the development of coronary artery spasm. However, no cardiac imaging modality has been able to demonstrate abnormal sympathetic innervation in patients with coronary artery spasm. The purpose of this study was to assess the presence and location of abnormal sympathetic innervation using iodine 123-metaiodobenzylguanidine (123I-MIBG) single photon emission computed tomography (SPECT) and to evaluate the clinical efficacy of 123I-MIBG SPECT as a noninvasive screening test in patients with coronary artery spasm. METHODS AND RESULTS: Coronary arteriography and a provocative test with intravenous administration of ergonovine maleate were performed in 26 patients (20 men, 6 women, mean age 48.2+/-12.0 years, range 20 to 67 years) who were suspected of having a coronary artery spasm. The subjects were divided into 2 groups: group 1 (n = 18) comprised subjects with a positive provocative test result, and group 2 (n = 8) comprised subjects with negative provocative test results. Ten healthy subjects served as controls. No abnormal MIBG uptake was observed in the control subjects. Abnormal sympathetic nervous innervation using 123I-MIBG SPECT was observed either as a reduced uptake or a defective pattern in the perfused areas in 13 of the 18 regions supplied by vessels of ergonovine-induced vasospasm. Normal sympathetic innervation, as evidenced by normal 123I-MIBG uptake, was noted in all of the 60 segments of normal vessel territories. Reduced uptake of 123I-MIBG was not detected in the perfused areas of 5 vasospasm-induced vessels (perfusion territory of left anterior descending coronary artery [LAD] and the right coronary artery [RCA] in 2 and 3 patients, respectively). The sensitivity and specificity of 123I-MIBG for detection of coronary artery spasm were 72.2% (95% confidence interval [CI] 55% to 89%) and 100%, respectively. The positive predictive and negative predictive values were 100% and 92.3% (95% CI 91% to 93%), respectively. CONCLUSION: 123I-MIBG SPECT is a feasible method to evaluate noninvasively and localize the territories of coronary arteries with spasm. Invasive diagnostic coronary arteriography with ergonovine provocation test may be unnecessary for diagnosis of coronary artery spasm in patients with typical resting pain, negative exercise test or normal thallium perfusion scan results, but showing abnormalities in 123I-MIBG SPECT.

3-Iodobenzylguanidine↗