심실상성 빈맥의 기전 규명에 있어서 심전기생리학적 지표인 △VACT와 VACT Ratio 의 가치

조정관(Jeong Gwan Cho),박상진(Sang Jin Park),류제영(Jay Young Rhew),배열(Youl Bae),김성희(Sung Hee Kim),김준우(Jun Woo Kim),김주한(Ju Han Kim),길광채(Gwang Chae Gill),박주형(Joo Hyung Park),정명호(Myung Ho Jeong),박종춘(Jong Chun Pa 대한내과학회 1996 대한내과학회지 Vol.51 No.2

N/A Background: Electrophysiologic methods useful in determining the mechanism of paroxysmal supra- ventricular tachycardia (PSVT) accurately and easily have been continuously studied. Most studies were focused on the development of a method to differentiate AVNRT and AVRT using the septal atrioventricular bypass tract, since these two tachycardias are very difficult to differentiate even with electrophysiologic study (EPS). Several methods previously reported have some limitation in accuracy and/or applicability, Objectives: The purpose of this study is to develop a new electrophysiologic parameter by evaluating the usefulness of the difference (△VACT) and ratio(VACT ratio) of VA conduction time (VACT) during right ventricular pacing at the cycle length of supraventricular tachycardia (SVT) in determining the mechanism of SVT and localizing accessory pathways (AP) in AVBT. Methods: Total of 94 SVT patients undergoing EPS and radiofrequency (RF) catheter ablation for 35 AVNRT (17 male, 18 female; mean age 45.6±17.2 years) and 59 AVRT (36 male, 23 female; mean age 37.5 ±15.3 years) were included in this study, The electrophysiologic mechanism of SVT and the location of APs in A VRT were confirmed by RF catheter ablation in all the patients. AVNRT was typical form in 34 patients and atypical (slow-slow) form in one. Among 59 APs, 19 (32.2%) APs were right side (12: free wall, RFW group; 7: septum, SPT group), 40 (67.8%) APs were left side (37: free wall, LFW group; 3: septum, SPT group), EPS was performed using the standard technique. 6F multipolar electrode catheters were positioned at the high right atrium (HBA), atrioventricular junction (HIS), right ventricular apex (RVA) in all the patients, and coronary sinus if needed. SVT was induced in all the patients with programmed electrical stimulation. VA conduction time (VACT) was measured from the onset of QRS complex to the onset of atrial electrogram from the HRA during SVT (VACT-SVT) and during RVA pacing at the SVT cycle length (VACT-RVP). △VACT was calculated by subtracting VACT-SVT from VACT- RVP and VACT ratio by dividing VACT-RVP by VACT-SVT. AVNRT and AVRT were differentiated using the previously reported criteria and then RF catheter ablation was performed. RF was delivered at the target site through a 7F 4 mm-tipped deflectable ablation catheter using continuous unmodulated sine wave with 350 KHz or 500 KHz generated from RF generator (RFG-3B, Radionics, Burlington, Mass or HAT 200S, Osypka, Germany). Results: The preexcitation index (PI) could be measured with a single ventricular extrastimulus in 22 (62.9%) of 35 AVNRT patients and 49 (83.1%) of 59 AVRT patients. PI was 139±31 (range 90-200) in AVNRT, 30±11 (range 15-40) in RFW group, 29 20 (range 10-70) in SPT group, and 92±24 (range 55- 160) in LFW group, showing a significant difference between each groups, but considerable overlap (52.6% of 76) between each groups except between AVNRT and AVRT with right side AP, DVACT was 126±20 (range 76-168) ms in AVNRT, 179 (range 4-35) ms in RFW group, 29 ±25 (5-76) ms in SPT group, 79±16 (50-110) ms in LFW group, showing a significant difference between AVNBT and 3 groups of AVRT and between 3 groups of AVRT except between RFW group and SPT group (p<0.01). The frequency of the patients with overlap in AVACT was lower than that in PI(52.6% vs. 24.5%, p<0.05). △VACT with a cut-off value of 50 ms differentiated the sideness (right vs. left) of APs in 58 (98.3%) of 59 AVRT patients, VACT ratio was 3.671.22 (range 2.20-8.30) in AVNRT, 1.10,1 (range 1.03-1.29) in RFW group, 120.2 (range 1.03-1.29) in SPT group, and 1.5±0.1 (range 1.30-1,86) in LFW group, showing no overlap between AVNRT and AVRT. AVNRT and AVRT were completely differentiated with VACT ratio with a cut-off value of 2.0. Conclusion : It is concluded that the mechanism of SVT may be accurately differentiated into AVNRT or AVRT using VACT ratio with a cut-off value of 2.0 and the location of accessory pathwa

영구형 심박조율기 시술에 대한 임상경험

조정관(Jeong Gwan Cho),정명호(Myung Ho Jeong),박종춘(Jong Chun Park),양승진(Seung Jin Yang),박찬형(Chan Hyung Park),길광채(Gwang Chae Gill),조길우(Keal Woo Cho),강정채(Jung Chaee Kang) 대한내과학회 1989 대한내과학회지 Vol.37 No.1

N/A Pacemaker implantation for symptomatic bradycardia is becoming popular recently in this country. Though its clinical benefit has been documented clearly there are still a lot of clinical problems arising from surgical problems, implanting techniques and pacemaker inherited problems. This study was designed to evaluate the indications, clinical manifestations and complications of 62 implantation procedures in 55 patients who had undergone the implantation procedure in Chonnam University Hospital by reviewing the pertinent clinical records. From 1983 to 1988, 62 implantation procedures in 55 patients (19 men and 36 women) were carried out. Annual numbers of implantation had been increasing, with 5 cases in the beginning year up to 20 cases in 1987, the numbers increased. The most common age was the fifties and patients older than fifty years comprised 74.5% of the total. The main symptoms which brought the 52 patients who underwent the first implantation to the hospital were syncope in 26, dyspnea in 14, dizziness in 9, shock in 2, and nonspecific in l. Electrocardiographic manifestations of the patients were atrioventricular block in 32 (58.2%, 28 complete AV blocks, 3 type II 2nd AV blocks, and one trifascicular block) and sick sinus syndrome in 23 patients (41.8%, 10 sinus arrests, 9 sinus bradycardias, 3 tachy-bradycardias, and one second degree SA block). Associated diseases were hypertension in 20, coronary artery disease in 7, cerebral infarction in 4, surgical correction of VSD in 2, dilated cardiomyopathy in 2, diabetes mellitus in 2, thyrotoxicosis in l, and liver cirrhosis in 1 patient. But, abaut one fourth of the patients had no associated disease. The systems implanted were all ventricular demand pacing system, among which 41 (70%) were multi-programmable. Pacing leads were introduced via the cephalic vein in most of the cases and via the external jugular vein in some cases. At implantation the pacing threshold was 0.67±0.25 volts (M±SD), electrode impedance 1258±266 ohm (M±SD), and intracardiac R wave amplitude 10.3±9.7 mvolts (M±SD). The causes of revision due to complications were 2 chronic exit blocks, 2 erosions of the generator or lead, one preerosion followed by infection after a revision, one generator pocket abscess shortly after an implantation, one power depletion, and 3 occasions of twiddler's syndrome in a patient. Other complications which were controllable without revision of the system were one indifferent electrode skeletal muscle pacing treated by reprograming the output, chronic increase of threshold in another 2, pacemaker syndrome in one treated by reprograming, and a hematoma in the generator pocket resolved by needle aspiration. We learned from this review that although pacemaker implantation has been helpful in the majority of the patients treated, same annoying and potentially life threatening complications warranted, and efforts to prevent or detect them early are necessary mention.

우측 방실우회로의 전극도자 절제에 효과적인 접근방법에 대한 연구

조정관(Jeong Gwan Cho),박우석(Woo Suck Park),배열(Youl Bae),안영근(Young Keun Ahn),류제영(Jay Young Rhew),김남호(Nam Ho Kim),이상현(Sang Hyun Lee),박형욱(Hyung Wook Park),박주형(Joo Hyung Park),정명호(Myung Ho Jeong),박종춘(Jong Chu 대한내과학회 1998 대한내과학회지 Vol.55 No.3

N/A Background: Although radiofrequency catheter ablation (CA) of the accessory pathway (AP) is very effective and safe, it has been reported that CA is more difficult in the right-side AP than the left-side AP, requiring the refinement of the conventional CA technique for the right-side AP. This study was, therefore, aimed to develop an effective technique for CA of the right-side AP. Methods: Fifty right-side APs in 45 patients which underwent CA were included in this study. The locations of APs were divided into 8 regions (anteroseptal, mid septal, posteroseptal, posterior, posterolateral, lateral, anterolateral, and anterior). After localizing APs, CA of the APs was attempted via the inferior vena cava (1VC) in all patients. If CA attempt via the IVC for more than 1 hour was failed, then CA was tried via the superior vena cava (SVC). Successful CA was defined as permanent loss of AP conduction even during infusion of isoproterenol (1-4 ㎍/min). The ways of approaching the ablation catheter to the successful target sites were classified into over-the-tricuspid valve approach (OV) via the IVC (IVC-OV), OV via the SVC (SVC-OV), under-the-tricuspid valve (UV) approach via the IVC (IVC-UV), and UV via the SVC (SVC-UV) and evaluated according to the AP locations. Results - The locations of the APs were anteroseptal in 5 APs, mid septal in 6, posteroseptal in 12, posterior in 3, posterolateral in 5, right lateral in 11, anterolateral in 4, and anterior in 4. Forty-eight (96.0%) of 50 APs were successfully ablated; 35 (70.0%) with primary 1VC approaches and 13 (26.0%) with secondat7 SVC approaches. As a successful approach, IVC-OV was 26 (54.2%); IVC UV, 9 (18.8%); SVC OV, 4 (8.3%), and SVC UV, 9 (18.8%). Secondary SVC approaches were required 7 (70.0%) in the lateral APs, 2 (50.0%) in the anterolateral Aps, 1 (25.0%) of the posterolateral APs, 1 (25.0%) in the anterior APs, 1 (20.0%) of the anteroseptal APs, and 1 (8.3%) in the posteroseptal APs but none in the midseptal and posterior APs. SVC-UV approach was used in 9 (69.2%) in 13 APs which were ablated with SVC approach. Conclusions: The ways of approach to successful target site in CA of the right-side APs are different according to the location and SVC approaches are frequently required in ablation of the lateral or anterolateral APs. Therefore, SVC approaches should be considered in these locations if the initial 1VC approaches are not successful.

심낭삼출환자의 심낭천자후 심전도에서 QRS 파 전위의 변화

조정관(Jeong Gwan Cho),박종수(Jong Soo Park),이명곤(Myung Kon Lee),안영근(Young Keun Ahn),박주형(Joo Hyung Park),정명호(Myung Ho Jeong),박종춘(Jong Chun Park),강정채(Jung Chaee Kang) 대한내과학회 1994 대한내과학회지 Vol.46 No.3

N/A Background: The ECG QRS voltage is determined mostly by ventricular mass and also by ventricular cavity size, distance from the chest wall to the electrical center of the heart, and electrical characteristics of the tissue between the skin and the heart. Low QRS voltage is observed in patients with significant pericardial effusion. However, the relationship between the QRS voltage and pericardial fluid amount has rarely been studied. The present study was performed to evaluate the possibility that pericardial fluid amount can be predicted by using the summed QRS voltage and to determine the factors influencing QRS voltage change after pericardial drainage. Methods: Twenty-nine patients with nontraumatic pericardial effusion of moderate amount or more were included in the study. Pericardial fluid amount was determined by measuring the actively drained pericardial effusion. The QRS voltage was measured from the peak of R wave to the nadir of q or s wave, whichever was deeper. Left ventricular volume, total ventricular volume, left ventricular mass, and distance from the chest wall to the center of the left ventricle (LV) were calculated from 2-D echo guided M-mode echocardiography of the ventricle. Results: Pericardial fluid amount was estimated by total QRS voltage of 12-lead ECG recorded before pericardiocentesis with the regression equation of Y=-50X+5950(r=-0.55, p<0.05). The change of QRS voltage after pericardial drainage was related with the left ventricular mass change (r=0.65, p<0.01) but not with the amount of drained pericardial fluid and the changes of the left ventricular volume and distance from the chest wall to the center of the LV. Conclusions: The surface ECG total QRS voltage can be used to estimate pericardial fluid amount. The most important determinant of the QRS voltage change after pericardia1 drainage is LV mass change, however, other factors remain to be determined.

방실결절회귀성 빈맥의 유발에 관여하는 심전기생리학적 인자에 관한 연구

조정관(Jeong Gwan Cho),신순철(Soon Chul Shin),류제영(Jay Young Rhew),배열(Youl Bae),김준우(Jun Woo Kim),김성희(Sung Hee Kim),김주한(Ju Han Kim),서정평(Jeong Pyeong Seo),박종철(Jong Chul Park),차광수(Gwang Su Cha),박주형,정명호(Myung Ho 대한내과학회 1997 대한내과학회지 Vol.52 No.6

N/A Objectives: Although a subtle balance between conduction time of the antgrade slow pathway and refractory period of the retrograde fast pathway is known to play the most critical role in the induction of AV nodal reentrant tachycardia(AVNRT), other electrophysiologic factors such as concealed conduction in to the fast pathway have been suggested to be responsible. The present study was performed to determine the electrophysiologic factors responsible for the induction of AVNRT. Methods: Total 34 subjects undergoing electrophysiologic study(EPS) including 9 normal subjects(SAVNP), 7 subjects with dual AV nodal pathways(DAVNP) but no inducible AVNBT, and 18 inducible AVNRT patients were included in this study. EPS was performed using the conventional technique. To evaluate the presence of concealed conduction into the fast AV nodal pathway(FP) and its effects on the effective refractory period(ERP) of the FP (FP-ERP) to a subsequent impulse, single(A2) and double atrial extrastimuli(A2A3) were given. FP-ERP of conducted A2 [FP-ERP-A2(+)] was measured with a second atrial extrastimulus(A3) following a first atrial extrastimulus(A2), which was delivered at a coupling interval 20-30ms longer than FP-ERP. ERPs of non-conducted A2 [FP-ERP-A(-)] was measured with A3 following A2 at coupling intervals 20 ms shorter than FP-ERP. Concealed conduction was considered to be present when A1A3 interval of A3 blocked at the FP with a longest A2A3 interval was longer than FP-ERP. Concealment index(CI)-1 and CI-2 were calculated by dividing FP-ERP-A2(-) by FP-ERP-A2(+) and FP-ERP, respectively. In addition, relationship between antegrade slow pathway conduction time(A2H2) and retrograde fast pathway conduction time(HA), retrograde AV conduction system block cycle length(VA-BCL), and retrograde AV conduction system EBP(VA-ERP) was evaluated by a regression analysis. Results: Concealed conduction was present in all the subjects. CI-1 was 0.63±0.04 and CI-2, 0.79±0.04 in SAVNP and 0.67±0.11, 0.68±0.07 respectively, in AVNRT patients in whom the antegrade slow pathway(SP) was ablated with catheter ablation, showing no significant difference in CI between 2 groups. At the time of induction of AVNRT with A2, A2H2. was significantly correlated with FP-ERP and FP-CT(r=OA43, p=0.04; r=0.507, p=0,02, respectively). By multivariate regression analysis, it was derived that A2H2 should be greater than 0.79 FP-ERP+1.57 FP-CT-0.44 HA-190(ms) (r=0.71, p< 0.05). Conclusion: Induction of typical AVNRT with A2 is determined by conduction time of the slow pathway, refractory period and conduction velocity of the fast pathway, and concealed conduction into the fast pathway.

관동맥질환의 진단에 있어서 Exercise Treadmill Score 의 의의

서정평(Jeong Pyeong Seo),조인종(In Jong Cho),류문희(Mun Hee Rheu),박종수(Jong Soo Park),이명곤(Myung Kon Lee),정명호(Myung Ho Jeong),조정관(Jeong Gwan Cho),박종춘(Jong Chun Park),강정채(Jung Chaee Kang) 대한내과학회 1997 대한내과학회지 Vol.52 No.3

N/A 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×maximal ST- segment deviation during or after exercise-4×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, ETS≤11) were composed of 15cases(mean age 60.2±7.4, male: female = 1.2: 1), group B(moderate risk, 5>ETS≥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.

인공 심박동기 환자에서 심실동기이상의 관련인자

김성수 ( Sung Soo Kim ),조정관 ( Jeong Gwan Cho ),김현국 ( Hyun Kuk Kim ),장수영 ( Soo Young Jang ),심두선 ( Doo Sun Sim ),윤남식 ( Nam Sik Yoon ),윤현주 ( Hyun Ju Yoon ),홍영준 ( Young Joon Hong ),박형욱 ( Hyung Wook Park ),김주 대한내과학회 2010 대한내과학회지 Vol.78 No.1

Background/Aims: Chronic right ventricular pacing (RVP) can lead to increased risks of ventricular dyssynchrony (VD), heart failure, and mortality. This study examined the factors influencing VD in patients treated with a permanent pacemaker (PPM). Methods: The study enrolled 139 patients (M:F=1:1.35, 66.8±1.0 years) who had permanent pacemaker implanted [AAI (R): 11, VVI (R): 39, VDD (R): 50, DDD: 39]. Their clinical characteristics, 12-lead electrocardiogram (ECG), echocardiography, and laboratory parameters were evaluated. The patients were divided into two groups according to the presence of VD. Results: VD was seen in 71.9% of the patients with a PPM. No significant difference was observed in the clinical characteristics, except for the indications and current action mode of the PPM. VD was more frequently associated with patients with AV block and ventricular pacing. The QRS duration and QTc interval were significantly wider in patients with VD (159.9±3.2 vs. 129.4±6.3 ms, p<0.001; 487.7±4.0 vs. 470.9±8.0 ms, p<0.05, respectively). On echocardiography, tricuspid regurgitation was more common in patients with VD. The N-terminal B-type natriuretic peptide (NT-proBNP) level was higher in the dyssynchrony group (431.4±66.1 vs. 202.8±40.8, p<0.05). Conclusions: Patients with AV block and ventricular pacing developed VD more frequently. A higher serum NT-proBNP level and prolonged QRS duration, QTc, and tricuspid regurgitation might be associated with VD. (Korean J Med 78:59-67, 2010)

운동부하 검사상 무증상 심근 허혈 환자의 관동맥 병변 소견

조인종(In Jong Cho),서정평(Jung Pyung Suh),류문희(Moon Hee Rheu),이명곤(Myung Kon Lee),박종수(Jong Soo Park),박주형(Joo Hyung Park),정명호(Myung Ho Jeong),조정관(Jeong Gwan Cho),박종춘(Jong Chun Park),강정채(Jung Chaee Kang) 대한내과학회 1994 대한내과학회지 Vol.47 No.5

N/A Objectives: Silent myocardial ischemia is defined as the presence of transient ischemic alterations in absence of angina or its equivalents. In recent reports, silent ischemia comprises about 60-80% of total ischemic events in patients with symptomatic angina and its prognosis is similar to typical painful angina, So, we studied to compare the difference of coronary angiographic features between painful angina and silent angina in patients with positive treadmill exercise test. Method: We studied retrospectively coronary angiographic features of 34 patients; 20 patients with painful treadmill exercise test were grouped in A and 14 patients without pain were grouped in B. Both groups were positive in Thallium corynary perfusion scan. Results: 1) There were no significant differences in sex, age, smoking and hypertension between group A and B but diabetes were more prevalent in group A than in B(p< 0,05) 2) Total exercise duration, ST segment deviation and rate pressure product were not different between two groups in treadmill exercise test. Although treadmill score was significantly low in group A (p<0.05), there was no singificant difference between two groups in case of subtracting treadmill angina index from treadmill score. 3) In dipyridamole Tl scan, defect volume ratio was not different in two groups although defect index was significantly greater in group A(p<0.05). 4) In coronary angiographic findings, there were no sigificant differences in number of stenosed vessels, left ventricular ejection fraction and left ventricular end diastolic pressure, but right coronary artery lesion is more common in group A than group B(p<0,05). 5) The most common clinical diagnosis of studied subject was unstable angina, But there were no statistically difference between two groups. Conclusion: This results suggest that patient with silent myocardial ischemia has similar coronary artery disease to those with painful myocardial ischemia, Early detection and treatment of silent ischemia is essential in the management of ischemic teart disease.

관상동맥 중재술을 시행 받은 40세 이하의 ST 분절 상승과

박종춘 ( Jong Chun Park ),조정관 ( Jeong Gwan Cho ),김주한 ( Ju Han Kim ),홍영준 ( Young Joon Hong ),안영근 ( Youngkeun Ahn ),강정채 ( Jung Chaee Kang ),김남윤 ( Nam Yoon Kim ),박인혜 ( In Hyae Park ),정명호 ( Myung Ho Jeong ) 대한내과학회 2012 대한내과학회지 Vol.82 No.2

Background/Aims: The prevalence of coronary artery disease has increased in young adults. We evaluated the differences in clinical characteristics and clinical outcomes in young patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). Methods: A total of 164 patients with acute myocardial infarction who underwent percutaneous coronary intervention were divided into two groups: the STEMI group (120 patients; mean age, 35.7±3.8 years; 118 males) and the NSTEMII group (44 patients; mean age, 35.7±4.3 years; 43 males). We analyzed clinical and angiographic characteristics and major adverse cardiac events (MACE), including death from any cause, non-fatal myocardial infarction, target lesion revascularization, and coronary artery bypass graft surgery, during a 1-year clinical follow-up of the two groups. Results: During hospitalization, Killip class II acute myocardial infarction (5.8% vs. 15.9%, p=0.041) was observed more frequently in the NSTEMI group. The levels of troponin-I (66.9±103.6 vs. 26.6±38.5 ng/mL, p=0.014) and N-terminal pro-brain natriuretic peptide (733.0±1,018.1 vs. 476.2±374.5 pg/mL, p=0.012) were significantly higher in the STEMI group. One-year MACE did not differ between the two groups. By multiple logistic regression analysis, bare metal stents (odds ratio, 3.360; 95% confidence interval, 1.105-10.217; p=0.033) and high lipoprotein (a) levels (odds ratio, 1.047; 95% confidence interval, 1.020-1.075; p=0.001) were independent predictors of 1-year MACE. Conclusions: Young patients with STEMI and NSTEMI have similar clinical outcomes. Bare metal stents and high serum lipoprotein (a) levels are independent predictors of MACE during 1-year clinical follow-ups in young patients with acute myocardial infarction. (Korean J Med 2012;82:175-184)

흉통환자에서 아최대 다단계 자전거 운동 부하 검사의 진단적 가치

박찬형(Chan Hyung Park),조정관(Jeong Gwan Cho),강정채(Jung Chaee Kang) 대한내과학회 1989 대한내과학회지 Vol.36 No.3

N/A Although exercise ECG has been accepted as the first choice of diagnostic procedures, documenting valuable indirect evidence of insufficient myocardial perfusion during exercise induced stress, its value in predicting the presence of coronary artery disease (CAD) in an individual patient has been questioned because of its low sensitivity and specificity. This limited value of the exercise test in predicting CAD is particularly real in the society with a low prevalence of CAD. The idea that the exercise test should be ordered and interpreted based on the results of pretest probability for CAD is gaining consensus. In order to study how accurately CAD can be predicted, we formulated the 5 predictor scoring system (5 PSS) which is modified from Goldman's scoring system and based on 5 parameters of the patients such as age, sex, nature of chest pain, serum cholesterol level and smoking habits. The scoring system was evaluated in 38 patents who had bicycle ergometer GXT and coronary arteriography at our Division of Cardiology. The following results were obtained: 1) In predicting CAD the sensitivity and specificity of the 5 PSS were 86% and 88% respectively and the positive and negative predictabilities were 90% and 83% each, while the sensitivity, specificity, positive predictability and negative predictability of bicycle GXT were 62%, 71%, 72% and 60% respectively. 2) By combining the results of the 5 PSS, the predictability of the bicycle ergometer GXT for CAD increased. The positive predictability of GXT for CAD increased from 72% to 100% when the 5 PSS scores were above 30 and the negative predictability of GXT for CAD increased from 60% to 91% when the scores were below 30. 3) Only 29% of the cases with positive bicycle ergometer GXT had CAD when the 5 PSS scores were below 30; while 78% of the cases with negative bicycle GXT had CAD when the scores were above 30. These results suggested that in predicting CAD, the pretest probability derived from clinical parameters using the 5 PSS can be very helpful in rational evaluations of the bicycle ergometer GXT.