OBJECTIVE: To investigate the prevalence of airway hyperresponsiveness induced by isocyanate at one petrochemical industry complex in Yeochon, Korea. METHOD: Questionnaires, allergic skin prick test, toluene diisocyanate (TDI)-specific IgE, and non-specific airway hyperresponsiveness (AHR) were studied in 73 exposed workers and 27 control subjects. Methacholine challenge tests were done and bronc hial responsiveness (BR index) was defined as log (% fall of FEV1)/ log (last concentration of methacholine +10). RESULTS: Twenty-three workers (31.5% ) had respiratory symptoms, 21 had nasal symptoms, and eight had skin symptoms. Exposed workers with respiratory symptoms (n=22) had significantly higher BR index than those without them (0.82+/-0.06 vs 0.60+/-0.02, p<0.05). Exposed workers tended to have higher BR index than controls (0.67+/-0.03 vs 0.62+/-0.02). Three exposed workers had PC20 methacholine <2.0 mg/ml. There were no significant differences in atopy score between exposed workers and controls (p>0.05). Specific IgE antibodies were found in 19.7% of exposed workers. FEV, showed a significant negative correlation with BR index (r =-0.25, p<0.05). Poor correlation was noted between BR index and atopy, smoking status, or exposure duration. CONCLUSION: These findings suggest that workers exposed to isocyanates are at higher risk of airway hyperresponsiveness.
Antibodies ; Immunoglobulin E ; Isocyanates* ; Korea ; Methacholine Chloride ; Plants* ; Prevalence ; Skin ; Smoke ; Smoking ; Toluene 2,4-Diisocyanate ; Surveys and Questionnaires

BACKGROUND: Inotropic agents have been shown to improve cardiac function in patients with congestive heart failure. The purpose of the present study is to evaluate the short-term efficacy and safety of denopamine(Cardopamin(R)), and orally available beta-stimulant, in patients with chronic congestive heart failure. SUBJECTS AND METHODS: Twenty-four patients(54.1+/-10.9 years, male:female=1.4:1) with chronic congestive heart failure whose functional classes were equal or greater than New York Heart Association(NYHA) Class II were enrolled in this study after informed consents were obtained. Upon completion of baseline evaluation, denopamine(Cardopamin(R)) was administered orally, startion with 15 mg per day and increased to 30 mg per day according to the clinical response of each patient. Blood pressure, heart rate, electrocardiographic(EKG) findings, AST, BUN, and creatinine were also followed up at 4 weeks' interval. The clinical effects and side effects at 4 weeks' interbal and echocardiographic examination at baseline and 8 weeks after trentment were evaluated. RESULTS: Mean dosage of denopamine(Cardopamin(R)) was 22.9+/-5.3mg per day. The clinical symptoms of 18(75%) of 24 patients were improved. The echocardiographic follow-up revealed a significant decrease in left vetricular(LV) end-Systolic dimemsion(fron 4.8+/-0.2mm to 4.5+/-0.1mm. p<0.005) and LV end-systolic volume(from 92.0+/-8.5ml to 80.3+/-4.5ml, p<0.005). However, there was no significant interval change in LV end-diastolic dimension, LV end-diastolic volume, ejection fraction, and fractional shortening. Blood pressure, heart rate, EKG findings, AST, BUN, and creatinine were not changed significantly during treatment. CONCLUSION: Above results suggest that short-term therapy of denopamine(Cardopamin(R)) may improve clinical symptom with no side effect in patients with chronic congestive heart failure, but the long-term efficacy remains to be determined with a randomized long-term follow up study.
Blood Pressure ; Creatinine ; Echocardiography* ; Electrocardiography ; Estrogens, Conjugated (USP)* ; Follow-Up Studies ; Heart ; Heart Failure* ; Heart Rate ; Humans

BACKGROUND: One of most important mechanisms of coronary stent restenosis is neointimal hyperplasia. Although the process of neointima formation is not fully understood, a special role has been advocated for adherent platelets. Previous studies have shown a clear benefit with combined antiplatelet therapy such as aspirin plus ticlopidine in reducing the rate of thrombotic occlusions of stented vessels. The purpose of this study was to evaluate the effects of duration of antiplatelet regimens on coronary stent restenosis. METHODS: After successful placement of coronary artery stents in 222 patients, we performed follow-up coronary angiograms in 99 patients (42.3%). Forty-six patients were randomly assi-gned to receive aspirin and ticlopidine for four weeks (Group I: 54+/-9 years: M 38, F 8) and 48 patients for 6 months (Group II: 58+/-8 years: M 38, F 10). RESULTS: There were no significant differences in clinical and procedural variables or coronary lesion characteristics before and after stenting. At 6 months after stenting, minimal luminal diameter was 2.16+/-0.93mm in Group I and 2.04+/-1.07mm in Group II (p-0.57). Late lumen loss was 0.80+/-1.07mm in Group I and 0.92+/-1.11mm (p-0.58) in Group II. The stent restenosis rate of Group I at 28.3% and that of Group II at 29.2% were not statistically significant between the two groups (p-0.92). CONCLUSIONS: The therapeutic duration of combined antiplatelet regimen with aspirin and ticlopidine after coronary stent does not affect stent restenosis rate.
Aspirin* ; Coronary Vessels ; Follow-Up Studies ; Humans ; Hyperplasia ; Neointima ; Phenobarbital ; Stents* ; Ticlopidine*

OBJECTIVES: The treadmill exercise eletrocardiography(ECG) is the most commonly used non-invasive method in the evaluation of patients with chest pain. But the accuracy of treadmill exercise ECG in detecting the coronary artery disease(CAD) is still controversial. To improve the accuracy of the treadmill exercise test, exercise treadmill score(ETS) based on exercise duration, degree of ST deviation, and treadmill anginal index during treadmill exercise ECG has been used. METHODS: The authors calculated ETS by simple equation(total exercise duration-5 X maximal ST-segment deviation during or after exercise-4 X treadmill angina index) and analyzed coronary angiograms of 173 patients(mean age '55.5 +/- 8.7, male: female=2.7: 1) who underwent treadmill exercise ECG and coronary angiography in Chonnam University Hospital from January, 1990 through March, 1993. RESULTS: 1) The studied subjects were subdivided into 3groups according to ETS. Group A(high risk, ETSETS>or=11) 71cases(mean age 60.2 +/- 7.4, male: female=3.3:1), group C(low risk, ETS>5) 87cases(mean age 54.8 +/- 9.2, male-female =2.5:1). Clinical diagnoses of the studiedsubjects were 63stable angina, 61unstable angina, 3acute myocardial infarction, and 46 old myocardial infarction. On coronary angiographic findings, 61patients had single vessel disesase, 23patients had two vessel disease and 13patients had three vessel disease. 2) The sensitivity of the treadmill exercise ECG in diagnosing coronary artery disease was 88% and the specificity was 46%. 3) One hundred percent of group A patients had CAD and 54% of them had multivessel disease, 75% of group B had CAD and 27% of them had multivessel disease, and 33% of group C had CAD and 10% of them had multivessel disease. 4) There were no significant differences in the siite of stenotic lesion and degree of stenosis according to ETS in the patients with single vessel disease. 5) There were no significant differences in left ventricular ejection fraction and left ventricular end-diastolic pressure among three groups. CONCLUSION: Exercise treadmill score is useful in predicting the presence and severity of CAD and that low ETS less than -11 may be an indicator of multivessel coronary disease.
Chest Pain ; Constriction, Pathologic ; Coronary Angiography ; Coronary Artery Disease* ; Coronary Disease ; Coronary Vessels* ; Diagnosis ; Electrocardiography ; Exercise Test ; Female ; Humans ; Jeollanam-do ; Male ; Myocardial Infarction ; Sensitivity and Specificity ; Stroke Volume

BACKGROUND: Coronary stent is known as an effective treatment in the intimal dissection after angioplasty and the prevention of restenosis. However, in-stent restenosis still remains a major concern in clinical stenting. METHOD: The Microstents were placed in 151 patients from May '96 to Aug '97 and performed follow-up coronary angiograms in 49 (32.5%) patients. To identify the clinical, angiographic and procedure-related variables that predict late restenosis within the stented artery, 49 patients (58+/-8 year:38 M, 11 F) were studied. Indications for stenting were 25 de novo (52.8%), 9 restenotic (18.7%), 8 suboptimal PTCA (16.7%) and 6 bail-out lesions (12.6%). All patients were treated with aspirin and ticlopidine for one month after stenting. The follow-up angiograms were obtained at 5+/-3 months and variables of 13 patients with restenosis were compared with those of 36 patients without restenosis. RESULTS: The in-stent restenosis rate was 26.5%. Univariate logistic regression analysis was used to determine how in-stent restenosis was influenced. Clinical diagnosis, presence of risk factors, lipid profiles, numbers of involved vessels, target arteries, lesion length, lesion types, stent length, maximal inflation pressure, predilation balloon size, reference vascular diameter, minimal luminal diameter, and stent to artery diameter ratio were analyzed. Among these variables, only lesion length before stent implantation was a predictor for in-stent restenosis (19.9+/-11.1 mm vs. 10.9+/-7.3 mm, p=.017). CONCLUSION: Lesion length before Microstent II implantation is the single predictor of late in-stent restenosis.
Angioplasty ; Arteries ; Aspirin ; Diagnosis ; Follow-Up Studies ; Humans ; Inflation, Economic ; Logistic Models ; Phenobarbital ; Risk Factors ; Stents ; Ticlopidine

BACKGROUND: Idiopathic left ventricular tachycardia (ILVT), one of common idiopathic ventricular tachycardias which develop without structural abnormality of the heart. It has been reported that ILVT has a typical QRS morphology of right bundle branch block and left axis and unique clinical and electrophysiological characteristics. Intravenous verapamil is shown to be very effective in acute termination. However, radio-frequency catheter ablation is now recommended as the treatment of choice for long-term managemnt. This study was performed to determine the clinical and electrophysiological characteristics of ILVT and to evaluate the effects of radiofrequency catheter ablation (RFCA) of ILVT. METHODS: Seventeen patients (12 men, 5 women:mean age : 39+/-15 years) with ILVT were included in this study. ILVT was diagnosed based on the results of electrocardiogram, echocardiogram, cardiac catheterization, and electrophysiology study (EPS). EPS was performed with the standard technique in fasting state for more than 6 hours. In patients with their clinical VTs reproducibly induced during EPS, RFCA was attempted using endocardial activation mapping and pace-mapping. The mode of induction and termination, response to verapamil, and site of origin of the ILVT were evaluated. The local electrogram chacteristics at the sites of successful catheter ablation were also evaluated in patients undergoing RFCA. RESULTS: All 17 patients presented with recurrent palpitation but none with syncope or sudden cardiac death. None had a significant heart disease. The spontaneous ventricular tachycardias were of right bundle branch block morphology with left superior axis in 11 cases, right inferior axis in 1, and northwest axis in 5. The VTs were terminated with intravenous verapamil in all of 14 patients receiving IV verapamil. VT of same morphology as the clinical VT was induced with programmed electrical stimulation in 13 cases (76.4%), of whom 2 cases required isoproterenol infusion. The most frequent mode of induction was single ventricular extrastimulation (7 cases). Mean cycle length of the induced VTs was 320+/-59 ms. RFCA was attempted in 11 cases and successful in 9 (82%). The successful ablation sites were and central mid septum (3 cases), posterior mid septum (3 cases), posterior apical septum (3 patients) of the left ventricle (3 patients). At the successful ablation sites, the local ventricular activation preceded the onset of QRS complex by 34+/-15 ms (range : 10-58) and the paced QRS complexes during pace-mapping were identical to those of the induced or spontaneous VTs in 11.7+/-0.4 leads (range : 11-12). However, Purkinje potential was recorded only in 2 cases. There were no complications associated with EPS and RFCA. CONCLUSIONS: The present study suggests that ILVT is mild in symptoms, highly sensitive to verapamil, mostly caused by reentry, and can be cured by radiofrequency catheter ablation guided by pace-mapping and activation mapping.
Axis, Cervical Vertebra ; Bundle-Branch Block ; Cardiac Catheterization ; Cardiac Catheters ; Catheter Ablation* ; Catheters* ; Death, Sudden, Cardiac ; Electric Stimulation ; Electrocardiography ; Electrophysiology ; Fasting ; Heart ; Heart Diseases ; Heart Ventricles ; Humans ; Isoproterenol ; Male ; Syncope ; Tachycardia, Ventricular* ; Verapamil

BACKGROUND: Idiopathic left ventricular tachycardia (ILVT), one of common idiopathic ventricular tachycardias which develop without structural abnormality of the heart. It has been reported that ILVT has a typical QRS morphology of right bundle branch block and left axis and unique clinical and electrophysiological characteristics. Intravenous verapamil is shown to be very effective in acute termination. However, radio-frequency catheter ablation is now recommended as the treatment of choice for long-term managemnt. This study was performed to determine the clinical and electrophysiological characteristics of ILVT and to evaluate the effects of radiofrequency catheter ablation (RFCA) of ILVT. METHODS: Seventeen patients (12 men, 5 women:mean age : 39+/-15 years) with ILVT were included in this study. ILVT was diagnosed based on the results of electrocardiogram, echocardiogram, cardiac catheterization, and electrophysiology study (EPS). EPS was performed with the standard technique in fasting state for more than 6 hours. In patients with their clinical VTs reproducibly induced during EPS, RFCA was attempted using endocardial activation mapping and pace-mapping. The mode of induction and termination, response to verapamil, and site of origin of the ILVT were evaluated. The local electrogram chacteristics at the sites of successful catheter ablation were also evaluated in patients undergoing RFCA. RESULTS: All 17 patients presented with recurrent palpitation but none with syncope or sudden cardiac death. None had a significant heart disease. The spontaneous ventricular tachycardias were of right bundle branch block morphology with left superior axis in 11 cases, right inferior axis in 1, and northwest axis in 5. The VTs were terminated with intravenous verapamil in all of 14 patients receiving IV verapamil. VT of same morphology as the clinical VT was induced with programmed electrical stimulation in 13 cases (76.4%), of whom 2 cases required isoproterenol infusion. The most frequent mode of induction was single ventricular extrastimulation (7 cases). Mean cycle length of the induced VTs was 320+/-59 ms. RFCA was attempted in 11 cases and successful in 9 (82%). The successful ablation sites were and central mid septum (3 cases), posterior mid septum (3 cases), posterior apical septum (3 patients) of the left ventricle (3 patients). At the successful ablation sites, the local ventricular activation preceded the onset of QRS complex by 34+/-15 ms (range : 10-58) and the paced QRS complexes during pace-mapping were identical to those of the induced or spontaneous VTs in 11.7+/-0.4 leads (range : 11-12). However, Purkinje potential was recorded only in 2 cases. There were no complications associated with EPS and RFCA. CONCLUSIONS: The present study suggests that ILVT is mild in symptoms, highly sensitive to verapamil, mostly caused by reentry, and can be cured by radiofrequency catheter ablation guided by pace-mapping and activation mapping.
Axis, Cervical Vertebra ; Bundle-Branch Block ; Cardiac Catheterization ; Cardiac Catheters ; Catheter Ablation* ; Catheters* ; Death, Sudden, Cardiac ; Electric Stimulation ; Electrocardiography ; Electrophysiology ; Fasting ; Heart ; Heart Diseases ; Heart Ventricles ; Humans ; Isoproterenol ; Male ; Syncope ; Tachycardia, Ventricular* ; Verapamil

BACKGROUND: Coronary stents are effective in the treatment of acute complications after angioplasty and the prevention of restenosis. However, complications may arise posttreatment, the major cinical problems are stent thrombosis and restenosis. All coronary stents are imported from western countries and are not covered by medical insurance in Korea. Korean stents should be developed to reduce patient's economic burden. METHODS: We placed five Maximum Arterial Re-Creation (MAC) and five Palmaz-Schatz (PS) stents in ten porcine coronary arteries. Stent and artery diameter ratio was 1.3 : 1.0. Follow-up coronary angiogram and histopathologic examinations were performed four weeks after stent overdilation injury. RESULTS: All of the stented arteries were patent on follow-up coronary angiograms. Angiographic diameter stenosis was 23.1+/-9.2% in MAC stents and 18.5+/-12.3% in PS stents and pathologic area stenosis was 35.6+/-11.4% in MAC stent and 39.8+/-9.9% in PS stent at 4 weeks after stenting, which were not different between two stents. Maximal intimal thickness (0.28+/-0.12 vs. 0.36+/-0.17mm) and neointimal area (1.83+/-1.01mm2 vs. 1.50+/-0.65mm2) were not different between MAC and PS stent. CONCLUSIONS: MAC stents are as effective as PS stents in the prevention of stent restenosis in a porcine stent restenosis model.
Angioplasty ; Arteries ; Constriction, Pathologic ; Coronary Vessels ; Follow-Up Studies ; Insurance ; Korea ; Stents* ; Thrombosis

BACKGROUND: Catheter ablation of accessory pathways using radiofrequency(RF) energy was recently introduced to cure accessory pathway related tachyarrhythmias. The purpose of the present study was to evaluate the efficacy and safety of radiofrequency catheter ablation of accessory pathways and to determine factors influencing the outcome of catheter ablation. METHODS: Electrophysiology study was performed with standard technique and catheter ablation of accessory pathways using RF and conventional ablation technique. The outcome of RF catheter ablation were evaluated according to the location and the overtness of accessory pathways. Eighty patients(Mean +/-SD age, 36+/-15 years ; 50 male, 30 female)comprising 49(61%) with Wolff-Parkinson-White(WPW) syndrome and 31(39%) with atrioventricular reentry tachycardia(AVRT) using concealed bypass tract underwent RF catheter ablation for total of 85 accessory pathways in the Chonnam University Hospital. Five(6.3%) patients had multiple accessory pathways. RESULTS: Seventy-nine(92.9%) out of 85 pathways and all the pathways in 75(93.8%) out of 80 patients were ablated successfully. The success rate showed no significant difference between patients with overt accessory pathways and patients with concealed accessory pathways(92.0% vs. 93.9%). However, the success rate in right free wall location(72.7% of 11) was significantly lower than that in the other sites (95.9% of 74, p<0.05). More attempts were tried to ablate right-sided accessory pathway than left-sided pathways(6.4+/-24.1 vs. 3.8+/-6.8, p<0.05). Three(3.8%) pathways recurred within 30 minutes after the initial successful ablation. Four(5.1%) pathways recurred from 16 hours to 7 months after completion of the initial successful ablation session during the mean follow-up period of 43+/-24 weeks(range, 2-84 weeks). This late recurrence was more frequent, although statistically insignificant, in right-sided accessory pathways(11.1% vs. 3.3%, p=0.22). All 4 recurrent pathways(1 at the same session, 3 at the repeated sessions) reattempted for ablation were successfully ablated. As procedure-related complications, second degree AV block developed in a patients with mid septal and posteroseptal pahways and hemopericardium in a patients with a left anterolateral pathway. CONCLUSION: RF catheter ablation of atrioventricular accessory pathways is very effective and safe, with a success rate of 93.8% and a complication rate of 2.5%. Right-sided accessory pathways are more difficult to ablate than left-sided accessory pathways, requiring the development of a better technique for right free wall pathways.
Ablation Techniques ; Atrioventricular Block ; Catheter Ablation* ; Catheters* ; Electrophysiology ; Follow-Up Studies ; Humans ; Jeollanam-do ; Male ; Pericardial Effusion ; Recurrence ; Tachycardia

BACKGROUND: The lesion length of coronary artery stenosis has been regarded as a risk factor for acute complication and long segment stenosis of the coronary artery is associated with a less chance of successful percutaneous transluminal coronary angioplasty(PTCA). Many new interventional techniques auch as excimer laser angioplasty, directional atherectomy, and long-balloon angioplasty catheter have been developed and used for long lesion of coronary artery stenosis. Only a little data is, however, available on long-balloon PTCA. This study was carried out to see the clinical results of PTCA using long-balloon angioplasty catheters. SUBJECTS AND METHODS: Fifty-four coronary arterial stenotic lesions in 49 patients(M:F=32:17, 54.48.9 years)were attempted to dilate with long-balloon PTCA. Clinical diagnoses in 49 patients were acute myocardial infarction in 13, old myocardial infarction in 9, unstable angina in 18, andd stable angina in 9. Lesion length and TIMI(Thrombolysis in Myocardial Infarction) flow of target lesions were measured before PTCA. PTCA was performed in standard fashion using long-balloon angioplasty catheters. Immediate success rate, complications, and retenosis rate were evaluated. RESULTS: The associated risk factors of atherosclerosis were hypertension in 16, hypercholesterolemia in 10, smoking in 27, and diabetes mellitus in 9 patients. The target vessels were 34 left anterior descending arteries, 6 left circumflex arteries, and 14 right coronary arteries. PTCA using long-balloon catheters was performed as an adjunct to suboptimal PTCA using standard balloon catheters in 6 patients. In the remaining 44 patients, long-balloon PTCA was primarily performed due to lesion length greater than 2.0 cm. The overall success rate of long-balloon PTCA was 85.2%, and the procedure-related complications were occurred in 12(22.2%) lesions. Restenosis was revealed in 9(50%) of 18 lesions which were evaluated with follow-up coronary angiography. CONCLUSION: Above results suggest that PTCA using a long-balloon angioplasty catheter is efficacious in dilation long segment stenosis of coronary artery with a low complication rate.
Angina, Stable ; Angina, Unstable ; Angioplasty ; Angioplasty, Balloon, Coronary* ; Arteries ; Atherectomy ; Atherosclerosis ; Catheters ; Constriction, Pathologic ; Coronary Angiography ; Coronary Stenosis ; Coronary Vessels ; Diabetes Mellitus ; Diagnosis ; Follow-Up Studies ; Humans ; Hypercholesterolemia ; Hypertension ; Lasers, Excimer ; Myocardial Infarction ; Risk Factors ; Smoke ; Smoking