The Clinical Outcome of Acute Myocardial Infarction with Normal Coronary Angiogram

BACKGROUND AND OBJECTIVES: Little data exist concerning the clinical outcome of patients with acute myocardial infarction (AMI) and angiographically normal coronary arteries (NCA). The purpose of this study was to evaluate the clinical outcome, the etiological factors and prognosis of these patients. SUBJECTS AND METHODS: The subjects were divided into two groups according to findings from coronary angiograms performed between January 1999 and December 2001, Group 1 : comprised of 46 patients, 34 males and 12 females, with a mean age of 50.4+/-11.9 years, had AMI with NCA ; Group II : 181 patients, 143 males and 38 females, with a mean age of 59.0+/-10.3 years, with AMI and total occlusion of the coronary arteries. RESULTS: The percentages of smoking and hypertension were similar between the two groups ; a higher prevalence rates of hyperlipidemia and diabetes were observed in group II compared to group I (p=0.03, 0.01). In group I, coronary spasm, combined inflammatory diseases and embolization were demonstrated in 32.6, 6.5 and 4.3% of subjects, respectively. The left ventricular ejection fraction was higher in group I than group II (51.5+/-11.3% vs. 46.2+/-10.5%, p=0.006). In-hospital outcomes, with the combined end-point defined as death, re-infarction and stroke was 0% in group I vs. 7.7% in group II (p=0.07). The mean long-term survival rate during the 26.5-month clinical follow-up were 100 and 92.2% in groups I and II (p=0.04), respectively. CONCLUSION: A coronary spasm is the most common cause of AMI with NCA, but these patients had the higher long-term clinical event-free survival.

The Changes of Fractional Flow Reserve after Intracoronary Nitrate and Nicorandil Injection in Coronary Artery Ectasia

BACKGROUND AND OBJECTIVES: Little data exist relating to the mechanism of myocardial ischemia in patients with coronary artery ectasia (CAE). The purpose of this study was to evaluate the fractional flow reserve (FFR), as an index of myocardial ischemia, in patients with CAE. SUBJECTS AND METHODS: Ten patients (7 males, 54.0+/-12.6 years) who diagnosed as CAE, by coronary angiographies, between March 2002 and July 2002, were analyzed. The clinical diagnosis of all the patients was unstable angina. FFR were performed using a pressure wire on the patients diagnosed with slow flow CAE from their coronary angiograms. After measurement of the baseline FFR using adenosine 20 microgram for the right coronary artery, and 24 microgram for the left anterior descending artery, the changes in the FFR with 500 microgram of intracoronary nitrate and 2 mg of Nicorandil were observed. RESULTS: Smoking was the most frequently associated risk factor. Type I CAE, according to Markis' classification, was the most prevalent at 60.0%. The values of the baseline FFR in the left anterior descending artery and right coronary artery, following the intracoronary injection of adenosine were both normal, and there were no significant changes in the FFR following the intracoronary injections of nitrate and Nicoronadil. CONCLUSION: The value of the FFR with CAE was normal, and an intracoronary injection of vasodilators did not change the FFR in patients with CAE. Therefore, vasodilator therapy might be beneficial for patients with symptomatic CAE.

Successful Coronary Interventions with the Aid of Abciximab (ReoPro (R)) in High-Risk Patients: Report of Two Cases / 대한구급학회지

Abrupt closure of coronary artery during coronary intervention is one of major limitations especially in high-risk patients. Platelets are responsible for composing acute thrombotic occlusion at the site of therapeutic arterial injury. Abciximab (platelet glycoprotein IIb/IIIa receptor blocker) might be helpful in preventing the acute thrombotic occlusion. We experienced an excellent effects of the drug in two cases of high-risk patients, unsuccessful thrombolytics and PTCA with acute occlusion. With additional use of abciximab we overcame the complications and succeeded in getting normal coronary flow and resultant successful angioplasties.

The Incidence of Dual Atrioventricular Nodal Pathways and the Differences of Their Electrophysiologic Properties According to the Inducibility of Atrioventricular Nodal Reentrant Tachycardia / 대한내과학회지

OBJECTIVES: Refractory period and conduction time of the slow and fast pathways in the atrioven-tricular node are known to be the most important determinant of the inducibility of atrioventricular nodal reentrant tachycardia (AUNRT) but their relationship has not been determined in Korean. METHODS: Two hundred and ten patients under-gone electrophysioiogic study. One hundred twenty two patients with dual AV nodal pathways were divided into two groups (group I, 77 patients with no inducible AVNRT; group II, 45 patients with inducible AVNRT). RESULTS: Antegrade dual AV nodal pathways were documented in 77 patients (47%) out of 165 patients on whom AVNRT was not induced, Antegrade ERP of slow pathway in paced rhythm (600 msec) was shorter in group II than in group I (331 +/- 14 msec vs 269 +/- 47 msec, p<0.05). Ventriculoatrial block cycle length (VABCL) and retrograde ERP of the AV conduction system were significantly shorter in group 2 than in group 1 (p<0.001). Maximum slow pathway conduction times in sinus rhythm and paced rhythm (600msec) in group 2 were significantly longer than in group 1 (sinus rhythm: 332 +/- 68msec vs. 379 +/- 88msec, p<0.005; paced rhythm: 332 +/- 69msec vs. 392 +/- 85msec, p<0.005). The ERP gaps of two AV nodal pathways of group 2 in sinus rhythm and in paced rhythm were also significantly longer than those of group 1 (sinus rhythm 41 +/- 3msec vs. 78 +/- 50msec, p<0.001; paced rhythm 36 +/- 32 msec vs. 72 +/- 19msec, p<0.005). The incidence of intact ventriculoatrial conduction was significantly higher in group 2 than in group 1 (p<0.05). Antegrade slow pathway conduction time (A2H2 interval) at the time of AVNRT induction with single atrial premature depolarization (APD) with a coupling interval over 10 msec less than that of an APD producing AH jump were not correlated with VABCL (r=0.193, p<0.05). CONCLUSION: Dual AV nodal pathways were observed in 47% of patients with no-inducible AVNRT group. The inducibility of AVNRT appears to be closely ralated to the some conduction characteristics of the dual pathways and the refractoriness, i.e. maximum slow pathway conduction time, the ERP gap of two pathways, retrograde fast pathway ERP, VABCL.

A Study on Electrophysiologic Mechanism and Clinical Characteristics of Paroxysmal Supraventricular Tachycardia / 대한내과학회지

OBJECTIVES: Accurate diagnosis of the mechanism and origin site of paroxysmal supraventricular tachycardia(PSVT) can be made using electrophysiologic study(EPS). Recently, radiofrequency catheter ablation technique has been introduced and widely used for the definitive treatment of various forms of PSVT, thereby precise determination of the mechanism of PSVT can be possible. It has been known that atrioventricular reentry tachycardia (AVRT) using concealed bypass tract is more frequent than atrioventricular nodal reentry tachycardia (AVNRT) in Korea. But it is not certain that those studies represent actual distribution of PSVT in Korea. This study was designed to determine the mechanism and clinical characteristics of PSVT in Korea. METHODS: We investigated 136patients in whom electrophysiolosic study was performed from October 1992 through October 1994 at the Chonnam National University Hospital, the only tertiary referral center of the Kwangju-Chonnam area of Korea. RESULTS: 1) The electrophysiologic mechanism of PSVT was AVNRT in 44patients(32.4%), WPW syndrome in 46(33.8%), AVRT using concealed bypass tract in 40(29.4%), sinoatrial nodal reentry tachycardia (SANRT) in 4(2.9%), and automatic atrial tachycardia(AAT) in 2(1.5%), ensuing that AVNRT is most common mechanism of PSVT with no preexcitation during sinus rhythm. 2) Male is more frequent than female in AVNRT, WPW syndrome, and AVRT, which was most prominent in WPW syndrome. 3) The first episode of symptom occured at the age of 34.9 +/- 17.3 years in AVNRT, 25.5 +/- 13.3 years in WPW and 26.3 +/- 15.0 years in AVRT(p<0.05). There was no significant difference in the duration of symptom. The tachycardia rate in WPW syndrome was 183.6 +/- 23.9 per minute and AVRT was 186.7 +/- 38.0 per minute, which were faster than that of AVNRT(161.7 +/- 28.6/min)(p<0.05). 4) There was no significant difference in the presenting symptoms and in the provocation factors between AVNRT and AVRT. CONCLUSION: AVNIlT is most common mechanism of PSVT with no preexcitation during sinus rhythm, developed at older age than WPW syndorme and AVRT, and had lower tachycardia rate than WPW syndrome and AVRT.

Changes of Intracoronary Electrocardiogram by Repeated Occlusion: Repefusion During Percutaneous Transluminal Coronary Angioplasty / 대한내과학회지

OBJECTIVE: Brief epidodes of ischemia have been shown to make the heart more resistant to subsequent ischemia in animal studies(known as ischemic preconditioning, IP). This phenomenon was tested in patients undergoing percutaneous transluminal coronary angioplasty(PTCA). METHODS: Thirteen patients who had significant epicardial coronary stenosis without myocardial infarction, ventricular hypertrophy or conduction defect, received two to four 2-min balloon inflations separated by 5 min of reperfusion. Surface electrocardiogram(S-ECG) and intracoronary electrocardiogram (IC-ECG) from an angioplasty guide wire were recorded before and after balloon inflation. RESULTS: The changes of ST segment were observed in 13 out of 15 lesions on IC-ECG and 7 on S-ECG. The maximal ST changes on IC-ECG and S-ECG were 20.2+/-13.7mm and 1.21.5mm respectively(p<0.01). The time to beginning of ST segment change after balloon inflation were 10.1+/-12.6 seconds and 63.3+/-14.2 seconds on IC-ECG and S-ECG, respectively(p<0.01). The maximal changes of ST segment on IC-ECG during the second inflation were significantly lower than that during the first(20.2+/-13.7 vs 16.312.3mm, p<0.05). However, changes of R wave, T wave and QT interval were not significantly different between two inflations. The recovery time to baseling ECG after initiation of reperfusion were 50.2+/-41.7 seconds and 38.5+/-29.6 seconds for the first inflation and the second, respectively(P<0.05). CONCLUSION: These results suggest that IC-ECG is more sensitive and reliable than S-ECG in detection of myocardial ischemia and that IP may occur during PTCA since ST segment shift is decreased and is normalized earlier at the second balloon inflation compared with the first.

A Case of Turner's Syndrome(46, XXqi) Associated with Large Atrial Septal Defect and Mitral Valve Prolapse

We descrive a 23-year-old female of 46, XXqi Turner's syndrome associated with large atrial sepatal defect(secundum type) and mitral valve prolapse who was admitted due to amenorrhea, sexual infantilism and exertional dyspnea. This patient had only one spontaneous menstrual period at the age of 15 and had a short stature without webbed neck. Chromosomal aberrations cause primarily structural defects of cardiovasculaqr system, and a variety of structural aberrations involving the X chromosome and cause partial or complete Turner's syndrome. In Turner's syndrome, bicuspid aortic valve or coarctaton of aorta is frequently combined, also aortic root dilatation, partial anomalous venous drainage, hypoplastic left heart and ventricular septal defect, atrial septal defect has been reported. However, this patient had not abnormalities in aortic valve and whole aorta. Atrial septal defect simultaneously with mitral valve prolapse in 46 XXqi Turner's syndrome have not been reported in Korea. We report this case with a brief review of the literature.

Clinical and Echocardiographic Features of Mid-ventricualr Obstruction of the Left Ventricle

BACKGROUND: Mid-ventricular obstruction(MVO) of the left ventricle has been reported to be associated with mid-ventricular hypertrophy, papillary muscle hypertrophy, severe apical hypertrophy, elderly hypertension, and dobutamine stress echocardiography(DSE). The aim of this study is to determine the clinical and echocardiographic features of MVO. METHOD: MVO was defined as systolic hourglass narrowing of the left mid-ventricle in the apical long axis view with turbulent flow exceeding 1m/s. Fifteen patients were suvjected to this retrospective analysis. Baseline patients characteristics were mean age 56(range, 26-74)years, male gender 10(66%). Associated diseases were hypertrophic cardiomyopathy 9, aortic stenosis 1, hypertension without left ventricular hypertrophy(LVH) 1, old myocardial infarction with apical aneurysm 2, stable angina 1, and idiopathic 1. DSE was performed in 7 of 15 subjected patients to evaluate the chest pain. RESULTS: All patients had mild symptoms; chest tightness, palpitation, and weakness, without syncope nor hypotension. MVO was observed in 10 at rest, and 5 after provocation ; DSE 3, VPB 1, atropine 1. Observed peak velocity in the mid-ventricle ranged from 1.2 to 5.5m/s(mean ; 2.8±1.6m/s). Left ventricular outflow tract obstruction defined as the peak flow velocity exceeded 1.5m/s, was also present in 8. in 7 underwent to DSE, systolic blood pressure was changed from 144±15mmHg at rest to 175±28mmHg at peak, heart rate from 73±12/min to 108±23/min, left ventricular end diastolic dimension from 42±5mm to 37±4mm, ejection fraction from 66±10% to 80±6%, and peak flow velocity at the mid-ventricle from 1.0±0.6m/s to 3.3±1.7m/s. CONCLUSION: MVO can be observed in patients without LVH and may account for clinical symptoms of chest discomfort. The mechanism of MVO, at least in part, and be explained with increased ventricular contractility, increased heart rate, and small left ventricular cavity size.

Clinical Experiences of Long-Balloon Percutaneous Transluminal Coronary Angioplasty

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.

A Study of Plasma Apolipoprotein A-1 and Apolipoprotein B Levels in Patients with Coronary Artery Disease

BACKGROUND: It is known that dyslipidemia plays and important role in atherogenesis and progression for the disease. Recently it was reported that apolipoprotein levels are important in athcrogenesis. In Korean patients the study of the apolipoprotein levels as for the risk factor for atherogenesis is still needed. Subjects and METHODS: The 107 patients who underwent coronary angiography to differentiate chest pain syndrome were subjected to this study. Thirty-two patients who had no significant coronary artery disease served as a control group and 75 patients who had one or more coronary stenoses more than 50% narrowing by luminal diameter served as the coronary artery disease(CAD) group. Plasma levels of total cholesterol, triglycerides, high density lipoprotein cholestero(HDL-C), apolipoprotein A-1(Apo- A1) and apolipoprotein B(Apo B) were measured from venous blood after overnight fastion, and the results were compared between the groups. RESULTS: The male gender and smoking habits were more prevalent in the CAD group. Total cholesterol levels were significantly higher in the CAD group but the HDL-C level was not significantly different in two groups though the mean level of the HDL-C was some lower in the CAD group. The Apo A-1 level was lowere in the CAD group while the Apo B level was higher in teh CAD group compared to those of the control, Apo B / Apo A-1 ratio much more distinctly discriminated the two groups. CONCLUSION: Theses results suggest that the plasma Apo-A-1, Apo B levels and the ratio of Apo B / Apo A-1 can be used for risk statification of CAD.

Clinical and Echocardiographic Changes after Short-Term Denopamine (Cardopamin(R)) Therapy in Patients with Chronic Congestive Heart Failure

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.

2 Cases of Apical Hypertrophic Cardiomyopathy with Left Ventricular Endomyocardial Calcification

Calcification of myocardium is most common in the site of an old infarction or in an aneurysmal wall. In addition, Myocardial calcification may occur in association with endomyocardial fibrosis and hyperparathyroidism, as a result of focal toxic or inflammatory myocardial necrosis, as well as in patients undergoing hemodialysis. Calcium deposits due to parasites and due to neoplastic disease may also be seen, But, left ventricular endomyocardial calcification associated with apical hypertrophic cardiomyopathy is very rare. This report describes 2 cases of apical hypertrophic cardiomyopathy with left ventricular endomyocardial calcification, diagnosed by the echocardiographic, angiographic and histologic findings.

Predictive Factors of Restenosis after Percutaneous Transluminal Coronary Angioplasty

BACKGROUND: One of major limitations of percutaneous transluminal coronary angioplasty(PTCA) is restenosis. The reliable factors predicting restenosis after successful PTCA might be important in the prevention and treatment of coronary restenosis after PTCA. METHODS: To see whether any of the clinical, angiographic. or procedural factors is likely coronary angiography due to recurrent ischemic symptoms and positive stress tests among 529 patients recived PTCA between Jul '90 and Sep '93 at the Chonnam University Hospital were analysed. RESULTS: 1) Follow-up coronary angiogram demonstrated restenosis in 67 patient(group A, 55.1+/-10.3 year, 58 male, 9 female) and no restenosis in 27 patients(group B, 55.4+/-10.3 year, 24 male, 3 female) demonstrating restenosis rate of 60.6% in this clinically suspicious group. 2) Age, sex, class and duration of angina, and clinical diagnosis were not different from each other between two groups. But the time interval from PTCA to follow-up angiogram was shorter in group A (5.3 +/-5.2 months) than in group B(9.1+/-5.6 months) and hypertension was more prevalent in group A (83.3%) than in group B(16.7%). 3) Angiographic findings such as AHA lesion types, lesion sites, TIMI flow, angulation, lesion length, branching lesion, dissection and residual stenosis were similar in two groups. But all of the eleven lesions with coronary artery calcification were found to develop restenosis. 4) As procedural factors, total ballon inflation time, the numbers of repeated inflations and maximal inflation pressure were not significantly different between two groups. CONCLUSION: Above results show that any single or combined clinical and angiographic findings except symptoms or signs suggesting myocardial ischemia, hypertension and coronary calcification could not predict the development of coronary restenosis ie the patients with shorter duration from PTCA to the clinical evidence suggestive of myocardial ischemia, hypertension and coronary calcification demonstrated by cineangiography were more likely to develop subsequent restenosis.

Predictive Factors of Restenosis after Percutaneous Transluminal Coronary Angioplasty

BACKGROUND: One of major limitations of percutaneous transluminal coronary angioplasty(PTCA) is restenosis. The reliable factors predicting restenosis after successful PTCA might be important in the prevention and treatment of coronary restenosis after PTCA. METHODS: To see whether any of the clinical, angiographic. or procedural factors is likely coronary angiography due to recurrent ischemic symptoms and positive stress tests among 529 patients recived PTCA between Jul '90 and Sep '93 at the Chonnam University Hospital were analysed. RESULTS: 1) Follow-up coronary angiogram demonstrated restenosis in 67 patient(group A, 55.1+/-10.3 year, 58 male, 9 female) and no restenosis in 27 patients(group B, 55.4+/-10.3 year, 24 male, 3 female) demonstrating restenosis rate of 60.6% in this clinically suspicious group. 2) Age, sex, class and duration of angina, and clinical diagnosis were not different from each other between two groups. But the time interval from PTCA to follow-up angiogram was shorter in group A (5.3 +/-5.2 months) than in group B(9.1+/-5.6 months) and hypertension was more prevalent in group A (83.3%) than in group B(16.7%). 3) Angiographic findings such as AHA lesion types, lesion sites, TIMI flow, angulation, lesion length, branching lesion, dissection and residual stenosis were similar in two groups. But all of the eleven lesions with coronary artery calcification were found to develop restenosis. 4) As procedural factors, total ballon inflation time, the numbers of repeated inflations and maximal inflation pressure were not significantly different between two groups. CONCLUSION: Above results show that any single or combined clinical and angiographic findings except symptoms or signs suggesting myocardial ischemia, hypertension and coronary calcification could not predict the development of coronary restenosis ie the patients with shorter duration from PTCA to the clinical evidence suggestive of myocardial ischemia, hypertension and coronary calcification demonstrated by cineangiography were more likely to develop subsequent restenosis.

Left Ventricular Function in Patients with Angina and Normal Coronary Angiogram

BACKGROUND: Angina with normal coronary angiogram has been called syndrome X or microvascular angina, but pathophysiologic mechanisms for chest patin in this group of patients are not known exactly. To observe the changes of left ventricular function in patients with angina and normal coronary angiogram, the authors analyzed the left ventricular systolic and diastolic function with echocardiogram and cardiac catheterization. METHODS: The authors performed resting and treadmill exercise electrocardiogram, 201TI dipyridamole scan, M-mode and Doppler echocardiogram, cardiac catheterization and coronary angiogram in patients with angina and normal coronary angiogram. The systolic and diastolic left ventricular function indices from M-mode and Doppler echocardiogram, left ventricular catheterization and coronary angiogram were analyzed in 12 patients excluding diabetes, hypertension, cardiomyopathy and esophageal motility disorders among 1626 patients who underwent coronary angiogram between Jan. 1991 and Aug. 1992 in Chonnam University Hospital. RESULTS: 1) Studied subjects were 12 patients, 5 male and 7 female, mean age was 51+/-9.4 year-old. Resting electrocardiograms were normal in 8 cases and ST-T changes in 4 cases. Ischemic ST-T changes were observed in all cases during treadmill exericise test and perfusion defects in 3 cases out of 8 cases during 201TI dipyridamole scan. 2) On echocardiogram, ejection fraction(EF) was 68.9+/-4.5%, fractional shortening(FS) 37.4+/-4.4%, ratio of left atrial to aortic root dimension(LAD/AOD) 1.2+/-0.1, OR slope 3.8+/-0.8c,/sec, mitral valve Doppler E/A velocity ratio[E/A(V)] 0.9+/-0.2, mitral valve Doppler E/A area ratio[E/A(a)]1.3+/-0.3, early diastolic deceleration rate(EDDR) 4.3+/-1.3m/sec2, isovolumic relaxation time(IVRT) 96.2+/-15.7msec, isovolumic contraction time(IVCT) 38.1+/-9.1 msec and aortic valve Doppler peak flow velocity[Ao(V)] 0.8+/-0.2m/sec. EF, FS, IVCT and A(V) were normal. LAD/AOD and IVRT were increased, but E/A(V), E/A(a), OR slope and EDDR were decreased compared to normal subjects. 3) On cardiac catheterization and angiogram, mean left ventricular end-diastolic pressure was 15.3+/-5.1mmHg and ejection fraction by left ventriculogram 78.2+/-7.4%. There was no regional wall motion abnormality. CONCLUSION: Above results suggest that angina with normal coronary angiogram may be associated with impaired left ventricular diastolic function.

The Effect of Collateral Circulation on Myocardial Perfusion during PTCA in Patients with Angina Pectoris

BACKGROUND: The coronary collateral circulation has been frequently observed in significant coronary artery disease and its protective role in ischemic myocardium is still remained unclear. But the study on the anti-ischemic effect in human model of ischemic myocardium is rare. METHODS: To observe the anti-ischemic role of coronary collateral circulation in ischemic myocardium, perfusion defect areas were measured during PTCA(percutaneous transluminal coronary angioplasty) in angina patients with single vessel disease and analyzed according to the grade of collateral circulation. The 99mTc-MIBI myocardial scanning images were obtained at 24 hours before PTCA with dipyridamole stress, at ballooning during PTCA and at 24 hours after the opening of the artery and perfusion defect volume ratios(DVR) were measured in each of the images of the patient with angina and single vessel disease. RESULTS: 1) Studied subjects were 14 patients(10 male, 4 female, mean age : 56.6+/-103) and subdivided into two groups. All patients had angina with single vessel disease, 7 proximal left anterior descending artery(LAD) stenosis, 4 middle LAD stenosis, 1 middle right coronary artery(RCA) stenosis and 2 proximal left circumflex artery(LCX) stenosis. Group A was composed of 7 patients with angina and coronary collateral circulation more than grade 1. Group B was 7 patients with angina and grade 0 collateral. 2) Mean age of group A was 62.4+/-8.2 years, 5 male and 2 female patients, That of group B was 56.6+/-8.9 years and all male patients. Group A was composed of 7 patients ; 5 unstable and 2 stable angina ; 2 proximal LAD stenosis, 3 midddle LAD stenosis, 1 middle RCA stenosis and 1 proximal LCX stenosis. One patients had grade 1, two patients grade 2 and four patients grade 3 coronary collateral circulation. All of the patients were unstable angina in group B showing 5 proximal LAD stenosis, 1 middle RCA stenosis and 1 proximal LCX stenosis. No collateral circulation was demonstrated in group B. 3) In group A, DVR was 17.5+/-13.9% on stress image before PTCA and 7.1+/-1.4% on the ballooning image during PTCA. DVR was smaller in ballooning image than in stress image(p<0.01). 4) In group B, DVR was 12.4+/-16.0% on stress image before PTCA and 26.6+/-10.0% on ballooning image during PTCA. DVR was larger in ballooning image than in stress image(p<0.001). 5) DVR on stress image and open image were not different in both groups, but DVR on ballooning image were 7.1+/-4.7% in group A and 26.6+/-10.0% in group B, which was larger than in group A(p<0.01). CONCLUSION: These results suggest that myocardial perfusion defect area may be smaller in angina patients with good collateral circulation than patients with no collateral, and coronary collateral circulation have a protective role on the jeopardized myocardium during coronary artery occlusion.

Clinical Study for Coronary Artery Stenting

BACKGROUND: Coronary artery stent has been introduced recently to overcome major problems of percutaneous trausluminal coronary angioplasty(PTCA). To evaluate the success rate, complications and predictive factors associated with restenosis in coronary artery stenting, clinical analysis after coronary srtery stent was performed. METHODS: Sixteen patients who underwent coronary artery stent in Chonnam University Hospital beteen Apr. 1992 and Dec. 1993 were observed. The authors analyzed the stent dilivery success, rate complications and restenosis after follow-up coronary angiogram. RESULTS: 1) The palmaz-Schatz stents were implanted in 16 patients(12 male, 4 female, mean age : 53.3 years) and clinical diagnosis of patients were 7 myocardial infarction, 8 unstable angina and one stable angina. Stents were implanted in 10 cases of left anterior descending arteries and 6 cases of right coronary arteries. Three stents were implanted in a patient with long spiral dissection after middle right coronary artery PTCA, single stent was implanted in the other patients. 2) Stent delivery was successful in all cases, but acute stent thrombosis developed just after bail-out procedure for PTCA-induced intimal dissection in myocardial infarction patient who had multivessel lesion and intracoronary thrombus. Subacute stent thrombosis and major bleeding requiring transfusion were not documented. 3) On follow-up coronary angiogram in 10 patients, no restenosis observed in 5 right coronary arterial stents, but restenosis developed in 3 of 5 left anterior descending artery stents. Restenosis was observed in none of 4.0mm stents, two of six 3.5mm stents and one of two 3.0mm stents. 4) Stent restenosis was observed in 3 cases of positive201TI dipyridamole scan which was performed one month after coronary artery stenting. CONCLUSION: Coronary artery stent is a safe and effective in elective procedure. The restenosis rate after intracoronary stent is lower in right coronary artery than left anterior descending artery and larger stent.

Radiofrequency Catheter Ablation of Atrioventricular Accessory Pathways : Factors Influencing the Outcome of Catheter Ablation of Accessory Pathways

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.

Clinical Effect of Penbutolol(Betapressin(R))on Hypertensive Patients

The only clinically avilable levo-isomer type of beta-recepter blocker is penbutolol sulfate, and it is already accepted as one of beta-receptor blockers for initial antihypertensive drug therapy according to the report of 1988 Joint National Committee on Detection, Evaluation, and Tratment of High Blood Pressure. To evaluate the antihypertensive efficacy, effect on the quqlity of life, and side effects of penbutolol recently introduced into Korea, penbutolol was administered to 29 essential hypertensive(mild 9, moderate10, and severe 10) patients for 12 weeks or longer. The result of the clinical analysis are as follows; 1) The mean age was 50.0+/-10.9(M+/-SD), and the sex distribution between male and female was16:13. 2) The blood pressure lowering effects of penbutolol as a monotherapy were marked in 16, moderate in 6, and insignificant in 2 cases. The systolic blood pressure was significantly decreased from 179.1+/-20.2 to 135.4+/-16.5mmHg(P<0.005), and the diastolic blood pressure from 112.6+/-13.5 to 84.0+/-11.9mmHg(P<0.005)after 12 weeks' penbutolol therapy. 3) The heart rate was significantly decreased from70.3+/-13.3 to 65.5+/-9.1 per minute(P<0.05). 4) The quality of life was improved markely in 5(17.2%) and slightly in 8 cases(29.6%). 5) There were no significant laboratory changes after 12 weeks' penbutolol therapy. 6) Two out of three cases with non-specific ST segment and T wave changes in EKG and two out of 9 cases with EKG were normalized, 2 cases of LAH with strain were improved. 7) The side effects of penbutolol were dizziness in 4, sexual dysfunction in 2, and skin rash in 1 case. 8) Final multifarious assessment of penbutolol therapy showed that it was very useful in 11(37.9%), useful in 4(13.8%) and slightly useful in 7 cases(24.1%). These reult suggest that penbutolol is a first-line antihypertensive agent with an effective antihypertensive action, improving quality of life, with no significant laboratory changes and few side effects.

A Case of Recurrent Pacemaker Twiddler's Syndrome

Pacemaker twiddler's syndrome is reported as a very rare complication of permanent pacemaker implantation. There was a recent report suggesting that the incidence of pacemaker twiddler's syndrome increase recently presumably as a result of the implantation of thinner and smaller pacemaker system than before. We experienced a case of pacemaker twiddler's syndrome complicated 3 times with the conventional method of implantation or replacement during 14 months after the first implantation(Optims MP 158C and Pacing lead 400, Telectronic)on June 13th 1987. This case was an 18 year-old high school girl who had suffered frequent syncope for 2 years and extertionl dyspnea for 5 years due to congenital complete heart block, of which block site was proved to be AV nodal by His bundle electrogram. Pacemaker twiddler's syndrome developed 3 times;firstly 6 weeks after the first implantation in the right subclavicular fossa, secondly 10 weeks after the replacement of the twisted pacing lead, thirdly 10 months after the change of implantation site to the left subcalvicular fossa with the replacement of the twisted and fractured lead. Finally, the pacemaker generator was anchored to the clavicular periostium and pectoralis fascia at several points by using Dacron pouch.