A Case of Anomalous Left Coronary Artery Originating from the Right Sinus of the Valsalva Presenting with Syncope / 대한내과학회지

Congenital anomalies of the coronary artery are associated with various symptoms including syncope, myocardial ischemia, and sudden cardiac death. The abnormality depends on the adjacent structure and pathway of the coronary artery. Most patients with an anomalous left coronary artery that arises from a right coronary sinus of the valsalva have no symptoms and are usually diagnosed at autopsy. Therefore, their first symptom might present as sudden death, particularly when the left coronary arterial course is between the aorta and the pulmonary trunk. Symptomatic patients could be diagnosed early with an anomalous coronary artery, and the risk of fatal events could be decreased by surgical correction. Here, we report the case of 62-year-old male who experienced a first episode of syncope with an anomalous left coronary artery arising from the right sinus of the valsalva with a separate orifice from the right coronary artery. He is alive and in good health receiving medical treatment, and has had no medical events for over 2 years.

Restoration of Sinus Rhythm by Defibrillation After Sudden Cardiac Arrest in a Patient with Chronic Atrial Fibrillation

Atrial fibrillation (AF) is a relatively common cardiac arrhythmia that can have adverse consequences due to a reduction in cardiac output and thrombus formation. For patients hemodynamically unstable due to AF, we recommend urgent direct current (DC) cardioversion. The importance of an automated external defibrillator (AED) in the emergency medical field for this purpose is very high. In addition, the distribution rate of an AED in public health care is on the rise. We herein describe a patient whose chronic AF was converted to a sinus rhythm by defibrillation during an episode of sudden cardiac arrest (SCA) which consequently improved left ventricular systolic function. We have experienced the importance of active use of AED.

Amiodarone Induced Multiorgan Toxicity in a Patient of Hypertrophic Cardiomyopathy With Atrial Fibrillation

Amiodarone is an antiarrhythmic drug known to have adverse effects on multiple organs. Most studies have reported the side effects of the drug, which may result from rapid administrations or from long-term, high dosage administrations. However, toxicity issues have also been reported from patients administered with low doses of the drug for a long period of time. Here we report a case of an 82-year-old female who had shown symptoms and signs of pulmonary, hepatic, and neurotoxicity after taking amiodarone for 14 months in order to treat her atrial fibrillation without regular outpatient follow-up. We highlight the importance of the recommended evaluations, including lung, liver, and thyroid functions, as well as the neurological examinations in patients treated with amiodarone for a long period of time during regular follow-up.

Displacement of dental implants into the focal osteoporotic bone marrow defect: a report of three cases

Focal osteoporotic bone marrow defect (FOBMD) is a radiolucent area corresponding to the presence of hematopoietic tissue rarely found in the jaws. FOBMD is most commonly located in the mandibular edentulous posterior area of a middle-aged female. From November 2011 to November 2012, we experienced three cases involving removal of implants that had accidentally fallen into the FOBMD area. All patients happened to be female, with a mean age of 54 years (range: 51-60 years). One case involved hypoesthesia of the lower lip and chin, while two cases healed without any complication. Displacement of an implant into the FOBMD area is an unusual event, which occurs rarely during placement of a dental fixture. The purpose of this study was to report on three cases of FOBMD and to provide a review of related literature.

Retromandibular Approach versus an Endoscope-assisted Transoral Approach to Treat Subcondylar Fractures of the Mandible

Surgical and Orthodontic Treatment of Unicystic Ameloblastoma Related to an Impacted Molar Tooth in the Mandible: Case Report

Ancient schwannoma in oral cavity: a report of two cases

This paper reports two cases of schwannomas arising from the oral cavity. One is an intraoral ancient schwannoma located at the left cheek, which evolved over a period of 13 years. The tumor was a well-demarcated buccal mass, which was located in the left lower first premolar area, with an obliterated the buccal vestibule, leaving the overlying mucosa intact. The second case was a central intraosseous schwannoma located from the left lower 1st molar periapical area to the left 3rd molar periapical area. Pathologically, the first mass was composed of the spindle shaped tumor cells with wavy nuclei beneath the fibroconnective tissue of the gingiva but second case mass was not. Occasional nuclear pleomorphism was observed but mitosis or necrosis was absent. There were Antoni A and B areas along with strong, diffuse staining with the S-100 protein. Ancient schwannomas were diagnosed. Schwannoma is a slow-growing benign tumor, and an ancient schwannoma that shows cellular atypism is a variant of a schwannoma caused by purely degenerative changes. To date, only limited cases of ancient schwannomas in the oral cavity have been reported.

A RETROSPECTIVE CLINICAL STUDY OF PERIAPICALLY INFECTED TEETH TREATED WITH PERIAPICAL SURGERY

Carcinoma ex pleomorphic adenoma of the parotid gland: Case report

Carcinoma ex pleomorphic adenoma is transformed at the incidence of 1-20% in pleomorphic adenoma and frequently recurred. It accounts for 10% of all malignant salivary tumors and its average age of occurrence is 60s. It will present in a large, long-standing pleomorphic adenoma or in one that was previously treated but has recurred. According to cell composition in malignant cell carcinoma, and clear cell adenocarcinoma. Most (75%) occur in parotid gland, while about 20% occur in the minor gland of the oral mucosa. The metastasis rate to regional lymph node is about 25%, and to distant organs about 33% and the 5-year survival rates are 40%. Though the treatment of the carcinoma ex pleomorphic adenoma is not established, it is treated ideally with and extensive resection, neck dissection, postoperative radiotherapy, and chemotherapy. When occurred in parotid gland, facial paralysis is reported. With a review of literatures, we report a case of carcinoma ex pleomorphic adenoma which operated with total parotidectomy and supraomohyoid neck dissection.

Pro-fibrillatory Effects of KATP Channel Opener and the Action Potential Duration Restitution Kinetics in Isolated Swine Right Ventricle

BACKGROUND AND OBJECTIVES: It remains to be defined how K[ATP] Channel Opener facilitates to induce ventricular arrhythmias. The purposes of this study are to assess the effects of K[ARP] Channel Opener, PCO400, on the action potential duration (APD) and APD restitution (APDR) kinetics, and their relationship with induction of ventricular tachycardia (VT)/fibrillation (VF), pro-fibrillatory effects. MATERALS AND METHODS: We recorded transmembrane potentials (TMPs) by microelectrode technique to explore the effects of PCO400 in ninetecn isolated perfused swine right ventricles. TMPs were recorded on the endoeardial side at the concentrations 0 micrometer, 1 micrometer, 2.5 micrometer, 5 micrometer, 10 micrometer, and washed-out period (1 hour). Ventricular refractory periods were measured while scanning djastole with premature ventricular beats during pacing at the cycle length of 600 ms at each concentration. The maximal slopes (Smax) of APDR were calculated with the data of S1S2 pacing and VF. RESULTS: PCO400 reduced APD90 (208+/-76 ms to 41+/-9 ms during S1, p<0.001, 111+/-32 ms to 54+/-28 ms during VF, p<0.001). While PCO400 tended to increase Smax of APDR at the concentration of 1 micrometer (0.6 to 0.7 by S1S2, 2.3 to 3.0 during VF), it reduced Smax at higher concentrations (-0.01 by S1-S2, p<0.05;-1.1 during VF, p<0.01). The increment of PCO400 concentration was associated with facilitated VT/VF induction (24.4% to 100%, p<0.001). Spontaneous VF induction rate was the highest at 1 micrometer (38.5%) which resulted in the highest Smax. CONCLUSION: PCO400 shows pro-fibrillatory effect by APD reduction and dynamic changes of Smax, Smax is closely related to spontancous induction of VT/VF, and APD90 shortening below 70 ms is critical for the maintenance of VT/VF.

Effects of Estrogen in the Myocardium of Aged Ovariectomized Rats

BACKGROUND AND OBJECTIVES: The effects of estrogen in the myocardium of aged ovariectomized rats, relating to the estrogen replacement onset time following an ovariectomy, and the replacement duration have not yet been established. The object of this study was to investigate the effects of estrogen replacement in the myocardium of aged ovariectomized rats. MATERIALS AND METHODS: 52 Female Sprague Dawley rats, about 3 months old, were subjected to sham surgery only (Group 1 ; control, n=9) ; a bilateral ovariectomy (OVX) and maintained untreated for a period of 12 weeks following surgery (Group 2 ; OVX only, n=16) ; estrogen conjugate 25 microgram/kg daily for 4weeks from the 8th post ovariectomy week (Group 3 ; OVX+estrogen replacement therapy : ERT 4weeks, n=10) ; estrogen conjugate 25 microgram/kg daily p.o for 12weeks directly post ovariectomy (Group 4 ; OVX+ERT 12weeks, n=17). We measured the left ventricular wall thickness (LVWT), the number of cardiomyocytes and interstitial fibrosis, edema, using light and electron microscopy. RESULTS: The LVWT in group 4 was 2.25 mm, which was significantly decreased compared to groups 2 and 3, which were 2.45 mm (p=0.014) and 2.46 mm (p=0.008), respectively. The LVWT in group 4 was not significantly different to that of group 1. Interstitial edema was significantly decreased in group 4 (41.2%) compared to that of group 3 (62.0%) (p=0.019). The electron microscopic findings showed a decrease of crystae and a loss of matrix, resulting in a whitish discoloration of the mitochondria in groups 2 and 3. A similar finding was not observed in groups 1 and 4. CONCLUSION: These results suggest that early administration and maintenance of estrogen following a bilateral ovariectomy could prevent the myocardial changes caused by estrogen deficiency.

A case of acute fulminant myocarditis improved with corticosteroid

No abstract available.

Coronary Blood Flow Velocity and Coronary Flow Reserve in Normal Left anterior Descending Coronary Arteries

BACKGROUND: Recently, assessment of left anterior descending (LAD) coronary flow by transthorasic Doppler echocardiography (TTDE) has been emerged as a useful tool in evaluation of microcirculatory function of coronary circulation. The measuring site of coronary flow by TTDE is distal LAD. But it was not fully investigated whether the distal flow velocity is identical to that of proximal segment. The purpose of this study is to compare coronary blood flow velocity and coronary flow reserve (CFR) in normal LAD according to its level. METHOD: 9 patients (1 male, 8 females; mean age 52.8+/-11.1years) were included for this study. Coronary flow velocity was measured with intracoronary Doppler guide wire at the proximal (before first diagonal branch), mid (after second diagonal branch), and distal segments of LAD at baseline and after intracoronary bolus injection of 18 microgram adenosine. Baseline and hyperemic average peak velocity (APV) and CFR were compared between segment. RESULTS: Baseline and hyperemic APV appears to be diminished from proximal (24.6+/-3.5 cm/sec, 55.8+/-10.7 cm/sec) to distal (21.7+/-6.9 cm/sec, 49.7+/-17.2 cm/sec) LAD without statistical significance. But, CFR showed no significant difference in each segments (proximal, mid, and distal segment; 2.3+/-0.26, 2.3+/-0.32, 2.3+/-0.48, p=0.95). As the increment of peak systolic velocity (PSV) from baseline to hyperemic state was larger than that of peak diastolic velocity (PDV), diastolic to peak systolic velocity ratio (DSVR) was decreased significantly by hyperemic state in proximal and distal segment (baseline; 2.1+/-0.8, 2.1+/-0.5 vs hyperemia; 1.8+/-0.6, 1.7+/-0.3, p<0.05). CONCLUSION: Coronary blood flow velocity appears to be decreased from proximal to distal segment of normal LAD without statistical significance. There were no differences in CFR between proximal, mid and distal segment of normal LAD.

Two Cases of Catheter Ablation of Atrioventricular Reentrant Tachycardia by Right Septal Bypass Tract Mapped Using Multielectrode Basket Catheter

It has been known that right side bypass tract ablation is more difficult and has higher recurrence rate than that of left side bypass tract, and often associated with atrioventricular block in patients with septal bypass tract. Multielectrode basket catheter (MBC) allows simultaneous rapid acquisition of numerous electrical signals generated by a selected surface area or volume of myocardium. We experienced two cases of successful catheter ablation of atrioventricular reentrant tachycardia by right septal bypass tract which were mapped by MBC with greater ease.

A Case of Essential Thrombocythemia Complicated by Acute Myocardial Infarction

Essential thrombocythemia, a subcategory of chronic myeloproliferative disorder, is characterized by absolute thrombocytosis due to excessive clonal proliferation of platelets, hyperaggregability of platelets and increased incidence of thrombosis and hemorrhage. Essential thrombocythemia may cause frequent vascular thrombosis, but it can be a rare cause of acute ischemic heart diseases such as acute myocardial infarction without atherosclerosis, unstable angina and angina pectoris. We report a case of essential thrombocythemia complicated by acute myocardial infarction. A patient with a previous history of vascular thrombotic complications (such as transient ischemic attack and deep vein thrombosis) was managed with 2.8 million units of intravenous urokinase, antiplatelet agent, ACEI, antianginal medications and hydroxyurea. There were clinically remarkable improvements and no further episodes of thrombotic ischemic vascular complications, including acute myocardial infarction.

Association of Arteriovenous Fistula Thrombosis with Anticardiolipin Antibody and Lipoprotein(a) Value in Patients with Maintenance Hemodialysis / 대한내과학회지

OBJECTIVES: Arteriovenous fistula (AVF) is Achilles hill of patients receiving maintenance hemodialysis, but thrombosis of AVF is a frequently encountered problem in maintenance hemodialysis patients. AVF thrombosis or occlusion is known to be associated with old age, underlying diabetes mellitus, increased fibrinogen and factor VIII, short AVF maturation time, low dialyzer blood flow, etc. Recently, several reports suggested that high titer of IgG anticardiolipin antibody (IgG-ACA) is associated with single or repeated clotting of AVF and elevated Lp(a) level is associated with vascular access occlusion in patients under maintenance hemodialysis. This study is to investigate the relationship between AVF thrombosis and the presence of elevated titiers of LP(a) and IgG-ACA. METHODS: This study included 20 patients with end stage renal disease under hemodialysis via AVF. Ten subjects have had one or more episodes of AVF obstruction (group A). Another 10 subjects without episodes of AVF obstruction (group B) were selected matching with age, sex, underlying disease, duration of hemodialysis, blood glucose level and lipid profile of subjects in group A. The IgG, IgM anticardiolipin antibody titers with indirect ELISA method and LP(a) level with turbidimetric assay were measured and analysed. RESULTS: Four subjects in group A showed positive IgG-ACA titer what of all subjects in group B were negative titer (p=0.03). Only one subject in group A and two subjects in group B showed positive IgM-ACA titer (p>0.05). The median value of Lp(a) was 32.75 (mg/dl), 43.1 (mg/dl) in group A and group B respectively and was not significantly different each other (p>0.05). CONCLUSIONS: In end stage renal patients receiving hemodialysis, positive IgG-ACA titier seems to be an independent risk factor of AVF thrombosis.

Pharmacologically Inducible Coronary Vasospastic Changes in Patient with Ischemic Heart Diseases with Normal Angiogram or Insignificant Coronary Lesion and Its Relationships with Risk Factors

BAKGROUND AND PURPOSES: Spasm of epicardial coronary arteries has been shown to play an important role in the pathogenesis of ischemic heart diseases. Spasm occurs in angiographically normal coronary arteries or arteries with organic atherosclerotic lesion and can result in rest angina, exertional angina or even myocardial angina or even myocardial infarction. However, pathogenetic mechanism of coronary artery spasm still remains unclear. The purpose of present study is to investigate characteristics of pharmacologically induced spasm of epicardial coronary artery in patient with ischemic heart disease with normal coronary angiogram or insignificant coronary artery disease (<25% narrowing), and to determine the relationship of coronary risk factors with coronary artery spasm in these patients group. METHODS: One hundred patients(male 47, female 53, age : 19-75 years) with ischemic heart disease(stable angina, unstable angina, myocardial infarction) who had normal coronary angiogram or angiographically insignificant coronary artery stenosis(<25% narrowing) were included for pharmacological provocation test for coronary artery spasm. Acetylcholine(ACH) and Ergonovine(Erg) were given intracoronarily(IC) in incremental doses(Ach : A1, 20micro, A2 50microg, A3 100microg and Erg : E1 5microg, E2 10microg, E3 25microg) either into coronary artery concordant with ECG leads showing ischemic ST-T changes in exercise ECG and/or 24-hour ambulatory ECG, or otherwise into right coronary artery. Erg provocation test was done after completion of acetylcholine provocation test. Constriction of coronary artery by more than 50% induced by either or both of the drugs were analysed in terms of incidence, degree, location of spasm and relation to risk factors. Coronary vasodilatory reserve function was tested by IC Doppler method for those patients with no spasm of epicardial coronary artery but with chest pain and ST-segment changes during provocation test. Relationship of spasm with various risk factors were investigated. RESULTS: 1) Ach or Erg test were positivie in 50 patients(50%). Among 75 patients who were tested by both drug, both test were positive in 17 patients(22.6%), and negative in 39 patients(52%), and Ach test was positive but Erg test was negative in 15 patients(20%). : The responses of Ach and Erg test were concordant in 75% of patients, the sensitivity and specificity of Ach test with reference to Erg test were 81% and 72%, respectively. 2) The characteristic features of spasm induced by Ach or Erg is focal narrowing in 34 patients and diffuse narrowing in 16 patients. The sites of spasm were LAD(23 cases), RCA(19 cases), LCX(5 cases), and in 3 cases, both LAD and LCX were narrowed. 3) In 50 patients showing no spasm, the typical chest pain or EKG changes was noted in 6 cases(12%). Of 6 patients, coronary vasodilatory reserve was decreased in 4 cases(66.7%). 4) Number of smoker was larger among spasm positive group(42%) than those among spasm negative group(12%)(p<0.01). CONCLUSION: The findings we observed in a limited series of patients suggest that in patients with normal or insignificant coronary angiogram, coronary spasm plays a role in the pathogenesis of broad spectrum of ischemic heart disease and that in patients with no coronary spasm but chest pain and ST-segment changes, coronary vasodilatory reserve is impaired, causing angina pectoris. Smoking may be one of the risk factors for coronary arterial spasm.

Pharmacologically Inducible Coronary Vasospastic Changes in Patient with Ischemic Heart Diseases with Normal Angiogram or Insignificant Coronary Lesion and Its Relationships with Risk Factors

BAKGROUND AND PURPOSES: Spasm of epicardial coronary arteries has been shown to play an important role in the pathogenesis of ischemic heart diseases. Spasm occurs in angiographically normal coronary arteries or arteries with organic atherosclerotic lesion and can result in rest angina, exertional angina or even myocardial angina or even myocardial infarction. However, pathogenetic mechanism of coronary artery spasm still remains unclear. The purpose of present study is to investigate characteristics of pharmacologically induced spasm of epicardial coronary artery in patient with ischemic heart disease with normal coronary angiogram or insignificant coronary artery disease (<25% narrowing), and to determine the relationship of coronary risk factors with coronary artery spasm in these patients group. METHODS: One hundred patients(male 47, female 53, age : 19-75 years) with ischemic heart disease(stable angina, unstable angina, myocardial infarction) who had normal coronary angiogram or angiographically insignificant coronary artery stenosis(<25% narrowing) were included for pharmacological provocation test for coronary artery spasm. Acetylcholine(ACH) and Ergonovine(Erg) were given intracoronarily(IC) in incremental doses(Ach : A1, 20micro, A2 50microg, A3 100microg and Erg : E1 5microg, E2 10microg, E3 25microg) either into coronary artery concordant with ECG leads showing ischemic ST-T changes in exercise ECG and/or 24-hour ambulatory ECG, or otherwise into right coronary artery. Erg provocation test was done after completion of acetylcholine provocation test. Constriction of coronary artery by more than 50% induced by either or both of the drugs were analysed in terms of incidence, degree, location of spasm and relation to risk factors. Coronary vasodilatory reserve function was tested by IC Doppler method for those patients with no spasm of epicardial coronary artery but with chest pain and ST-segment changes during provocation test. Relationship of spasm with various risk factors were investigated. RESULTS: 1) Ach or Erg test were positivie in 50 patients(50%). Among 75 patients who were tested by both drug, both test were positive in 17 patients(22.6%), and negative in 39 patients(52%), and Ach test was positive but Erg test was negative in 15 patients(20%). : The responses of Ach and Erg test were concordant in 75% of patients, the sensitivity and specificity of Ach test with reference to Erg test were 81% and 72%, respectively. 2) The characteristic features of spasm induced by Ach or Erg is focal narrowing in 34 patients and diffuse narrowing in 16 patients. The sites of spasm were LAD(23 cases), RCA(19 cases), LCX(5 cases), and in 3 cases, both LAD and LCX were narrowed. 3) In 50 patients showing no spasm, the typical chest pain or EKG changes was noted in 6 cases(12%). Of 6 patients, coronary vasodilatory reserve was decreased in 4 cases(66.7%). 4) Number of smoker was larger among spasm positive group(42%) than those among spasm negative group(12%)(p<0.01). CONCLUSION: The findings we observed in a limited series of patients suggest that in patients with normal or insignificant coronary angiogram, coronary spasm plays a role in the pathogenesis of broad spectrum of ischemic heart disease and that in patients with no coronary spasm but chest pain and ST-segment changes, coronary vasodilatory reserve is impaired, causing angina pectoris. Smoking may be one of the risk factors for coronary arterial spasm.

Effect of L-Arginine on Post-Ischemic Myocardial and Vascular Stunning in Open-Chest Dogs

BACKGROUND: Although recent studies have demonstrated that infusion of L-arginine reduces myocardial necrotic area during prolonged ischemia, its effects on transient postischemic myocardial dysfunction(myocardial stunning) and microvascular dyfunction(vascular stunning) are not well known. To investigate whether intravenous administration of L-arginine, physiological nitric oxide(NO) precursor, during reperfusion would attenuate postischemic myocardial dysfunction and microvascular dysfunction, 15 open-chest dogs were studied. METHODS: In 15 pentobarbital anesthesized open-chest dogs, left circumflex coronary artery was occluded for 20 minutes and was followed by a reperfusion for 60 minutes. L-Arginine(30mg/kg)(L-arginine group, n=8) or saline(control group, n=7) was given intravenously by a bolus 1 minute before reperfusion and was followed by a continuous infusion(10mg/kg/min) for 30 minutes during reperfusion. Before coronary occlusion and 60 minutes after reperfusion, coronary blood flow(CBF) and coronary vascular resistance(CVR) wre measured after intracoronary injection of each of acetylcholine(0.01/kg) and adenosine(1.5/kg), and reactive hyperemia with coronary occlusion(RH20) for 20 seconds was measured. Myocardial segment thickening in the area of ischemia-reperfusion was measured using 2D-echocardiography. The echocardiographic images were digitized and analyzed by cardiac image analyzer. RESULTS: The results obtained 60 minutes after reperfusion were as follows. 1) CBF was decreased by 41% in L-arginine group vs 30.1% in control group(p < 0.05) and CVR was increased by 83.9% in L-arginine group vs 19.3% in control group after 60 minutes of reperfusion, compared with pre-occlusion baseline values. 2) Percent change of CBF was decreased in control group(acetylcholine by 25.8%, adenosine by 29.2%, RH20 by 39.8%), while it was increased in L-arginine group(acetylcholine by 60%, adenosine by 22%, RH20 by 26.7%). Percent change of CVR was increased in control group(acetylcholine by 10.5%, adenosine by 6.9%, RH20 by 21%), but it was decreased in L-arginine group(acetylcholine by 10%, adenosine by 6.6%, RH20 by 1.6%). Increase of CBF and decrease of CVR were significant on acetylcholine and RH20 between control group and L-arginine group. 3) Fraction of myocardial segment thickening was significantly decreased in L-arginine group(by 80%) compared with control group(by 61.7%, p < 0.05). CONCLUSIONS: The finding that L-arginine depressed post-ischemic myocardial contractil function suggests that systemic infusion of L-arginine has unfavorable effect on myocardial stunning. In contrast, the finding that L-arginine improved CBF and CVR with acetylcholine and adenosine and reactive hyperemia indicates that L-arginine may exert a beneficial effect on vascular stunning. These results suggest that L-arginine may have independent effects on myocardial stunning and vascular stunning.

Relation between QT Dispersion and Late Potential in Acute Myocardial Infarction

BACKGROUND: QT dispersion(QTD=QTmax-QTmin) on the 12 lead ECG has been known to reflect regional variation of ventricular repolarization, and thus a marker of an increased risk of arrhythmia events. Late potential(LP) on signal averagina ECG(SAECG) is independent risk factor of ventricular arrhythmia following acute myocardial infaction(AMI). However, the relation between LP and QTD as indicator of electrophysiologic instability in AMI remains to be determined. METHOD: To determine whether there is a difference in QTD between in parients with AMI during acute phase and in normal control and whether thrombolytic therapy is assiciated with a reduction in QTD, and to determine the relationship between change of QTD and late potential on SAECG, we studied 71 patient with AMI(male 54, female 14, mean age 57yrs) and 23 controls(malw 17, female 6, mean age 58yrs). QT interval was measured on a standard 12 lead ECG in patients with AMI on admission, 2 hours after urokinase IV and 10-14 days post-AMI, and QT dispersion was calculated by difference of maximal and minimal corrected QT interval(QTmax-QTmin). A signal averaged ECG was recorded in 36 patients before discharge and coronary angiogeaphy(CAG) was performed in all patients 10-14 days post-AMI. RESULT: QTD is significantly increased in AMI compared to control(78.7+/-39.5ms vs. 24.6+/-22.3ms, P < 0.01). In patients who received thrombolytic therapy with urokinase, QTD is decreased from 75.0+/-34.4ms to 53.9+/-36.0ms(P < 0.01), whereas there is no significant change in patients who did not received thrombolytic therapy(84.8+/-47.6ms vs. 78.9+/-36.2ms, NS). There in no difference in QTD between patients with positive LP(68.4+/-23.6ms) and those with negative LP(77.8+/-32.1ms) on admission, those with positive LP(66.6+/-27.6ms) and those with negative LP(56.0+/-26.4ms) after 10-14days post-AMI. But magnitude of change of 10-14 days post-AMI QTD in patients with negative LP is larger than those with positive LP(-21.7+/-33.4ms vs. -1.8+/-15.2ms, P=0.06). CONCLUSION: QTD in acute phase of AMI is significantly reduced by the thrombolytic therapy. Patients with negative late potential tent to have greater QTD reduction within 14 days after AMI. These finding suggest that QT dispersion in patients with AMI can be reduced by early recanalization and its reduction is associated with the presence of late potential.