Impacts of Atherosclerotic Coronary Risk Factors on Atherosclerotic Surrogates in Patients with Coronary Artery Disease

BACKGROUND AND OBJECTIVES: The carotid intima-media thickness, endothelial function and arterial stiffness have been shown to be parameters of atherosclerosis. We have performed this study to evaluate the impact of atherosclerotic coronary risk factors on several atherosclerotic parameters in patients with coronary artery disease. SUBJECTS AND METHODS: The study subjects consisted of one hundred and forty (140) consecutive patients (mean age: 61 years, and 85 males), who demonstrated via coronary angiogram more than 50% stenosis in at least 1 major coronary artery. In an overnight fasting state, the carotid intima-media thickness (IMT), and endothelial function (flow-mediated brachial artery dilatation, FMD) were measured by high-resolution ultrasound, and arterial stiffness (pulse wave velocity, PWV) was measured by using a non-invasive pulse wave analyser. RESULTS: The hypertensive group showed more evidence of greater arterial stiffness (aorta; 8.5+/-1.0 m/s vs. 7.9+/-1.2 m/s, p=0.004, and greater stiffness of the artery of the lower extremity; 9.2+/-1.2 m/s vs. 8.7+/-1.3 m/s, p=0.010), which was measured by the pulse wave velocity, than that of the normotensive group. The carotid IMT and the endothelial function showed no significant differences between the two groups. Furthermore, these parameters did not show significant differences with other parameters such as diabetes mellitus, smoking, and hyperlipidemia. Multivariate analysis revealed that hypertension and systolic blood pressure were still the independent factors of arterial stiffness, but carotid IMT and endothelial function were not independent factors. CONCLUSION: Hypertension and systolic blood pressure are the independent factors of arterial stiffness in patients with coronary artery disease (CAD), but this study did not show that carotid IMT and endothelial function made a significant difference in arterial stiffness. However, in this study, other risk factors were not associated with the differences of these parameters.

Correlation between Endothelial Function and the Extent of Coronary Atherosclerosis

BACKGROUND AND OBJECTIVES: The purposes of this study were to provide evidence of any correlation between the endothelial dysfunction and the extent of coronary atherosclerosis, and the relationship between the endothelial function and individual atherosclerosis risk factors in patients with significant coronary artery stenosis. SUBJECTS AND METHODS: The endothelial function was measured by hyperemia induced brachial artery dilation, using high resolution ultrasound, in 284 consecutive patients (mean age 59 years, men: 176) having undergone coronary angiography. The subjects were divided into four groups according to the number of coronary arteries narrowed by more than 50%; 0 (n=88), 1 (n=98), 2 (n=54) and 3 (n=44). The endothelial functions were compared to see if significant coronary artery disease was present, according to the groups and the presence of individual atherosclerosis risk factors. RESULTS: There were no significant differences in the endothelial dysfunction between the narrowed and normal coronary artery groups (4.66+/-2.45% vs. 4.43+/-1.53% p>0.05) or between the four groups. The endothelial function in patients with significant coronary artery stenosis (n=196) was significantly lower when coupled with hypertension (n=84, 2.99+/-2.4% vs. 4.20+/-2.4%, p<0.05), diabetes (n=44, 4.07+/-2.7% vs. 4.84+/-2.5%, p<0.05) and hypercholesterolemia (n=82, 4.26+/-1.9% vs. 4.95+/-2.7%, p<0.05), but not with smoking. CONCLUSION: The endothelial function showed no difference according to the extent of coronary atherosclerosis. Risk factors of atherosclerosis, such as hypertension, diabetes mellitus and hypercholesterolemia, can deteriorate the endothelial function further, even in the patients with significant coronary artery stenosis.

Is Arterial Stiffness Useful in Differentiating Patients with Coronary Artery Disease from Risk Factor Only Patients?

BACKGROUND AND OBJECTIVE: The endothelial function, carotid intima-media thickness (CIMT) and arterial stiffness are known as surrogates of atherosclerosis, but it is not clear whether these surrogates can discriminate patients with coronary artery disease (CAD) from those with risk factor. The intention was to compare these 3 surrogates in patients with CAD and those with risk factor only. SUCJECTS AND METHODS: Forty-three patients with CAD (mean age:58, 32 men), 18 age and sex matched healthy people (mean age:52, 9 men) and 16 patients (mean age:53, 12 men) with atherosclerosis risk factor only were enrolled. The endothelial function (flow-mediated brachial artery dilation, FMD) and CIMT were measured by high-resolution ultrasound and the arterial stiffness by an oscillometric method. RESULTS: There was a significant difference between the CAD and risk factor groups (3.46+/-1.3% vs. 5.77+/-2.54%, p0.05) in the measured FMD. The CIMT showed a significant difference between the CAD and healthy groups (0.89+/-0.14 mm vs. 0.78+/-0.07 mm, p0.05). There were significant differences among all groups in relation to the arterial stiffness (CAD group:1524+/-289 cm/sec, risk group:1342+/-202 cm/sec, healthy group:1195+/-119 cm/sec, p<0.05). The arterial stiffness showed significant correlation with the FMD (r=-0.322, p=0.005) and CIMT (r=0.310, p=0.007). CONCLUSION: Of the 3 surrogates, the arterial stiffness measurement showed the best reliability in differentiating the CAD from the risk factor only groups as well as from healthy subjects. This study suggests the arterial stiffness can be used as a novel noninvasive test for early diagnosis of CAD in patients at high risk of atherosclerosis.

A Case of a Successful Percutaneous Coronary Intervention Using Percusurge(r) System in a Massive Intracoronary Thrombi Patient

A massive intracoronary thrombus, during percutaneous coronary intervention (PCI), implies a high risk of major adverse cardiac events. We experienced a case of successful PCI, using Percusurge(r), in an acute myocardial infarc-tion patient, with massive intracoronary thrombi. The TIMI 3 coronary flow could not be restored during a primary PCI of the right coronary artery, despite repeated ballooning, intracoronary urokinase injection, parenteral abciximab and heparin. However, successful PCI, with stenting, was performed by aspiration of the large intracoronary thrombi, with the Percusurge(r) system, 5 days after the primacy PCI.

A Case of a Successful Percutaneous Coronary Intervention Using Percusurge(r) System in a Massive Intracoronary Thrombi Patient

A massive intracoronary thrombus, during percutaneous coronary intervention (PCI), implies a high risk of major adverse cardiac events. We experienced a case of successful PCI, using Percusurge(r), in an acute myocardial infarc-tion patient, with massive intracoronary thrombi. The TIMI 3 coronary flow could not be restored during a primary PCI of the right coronary artery, despite repeated ballooning, intracoronary urokinase injection, parenteral abciximab and heparin. However, successful PCI, with stenting, was performed by aspiration of the large intracoronary thrombi, with the Percusurge(r) system, 5 days after the primacy PCI.

Effect of Coronary Angioplasty on QT Dispersion

BACKGROUND AND OBJECTIVES: The change in QT dispersion (QTd) immediately after balloon angioplasty reflects the immediate impact of ischemia. We intended to analyze the immediate impact of ischemia on myocardial repolarization. MATERIALS AND METHODS: Forty-six patients who underwent percutaneous coronary intervention were enrolled. The standard 12-lead electrocardiogram (ECG) was recorded just before, during, and 1 minute, 5 minutes and 10 minutes after ballooning. QTd was determined by the difference between the maximum and minimum QT interval (QTi). We then calculated the corrected QTi (QTc) using Bazett's formula. QTd and QTi were compared according to the site of the ballooned vessel, number of ballooned vessels and history of acute myocardial infarction. RESULTS: QTd just before, during, and 1 minute, 5 minutes and 10 minutes after ballooning were 35.21+/-10.36 msec, 54.56+/-16.89 msec, 50.91+/-14.20 msec, 45.52+/-9.6 msec and 38.56+/-10.89 msec, respectively. QTd increased markedly during ballooning, but after myocardial ischemia was relieved, decreased rapidly. Ten minutes after ballooning, QTd was reduced to a similar level as that of baseline. There were no significant differences between the AMI and non-myocardial infarction groups, single-vessel and multi-vessel groups, and the location of the stenosed artery. There was no significant difference in QTi according to different stenosed vessel. CONCLUSION: QT (QTc) dispersion increased rapidly with myocardial ischemia and reduced rapidly after the myocardial ischemia was resolved. Therefore, increased QTd can be used as an early clue of myocardial ischemia.

Safety and efficacy of arbutamine stress echocardiography / 대한내과학회지

BACKGROUND: Exercise and pharmacologic stress echocardiography are widely used for detecting coronary artery disease. Arbutamine is a new synthetic mild alpha1-receptor and - receptor agonist developed specifically for stress echocardiography. Arbutamine is superior to dobutamine owing to its enforced chronotropic action than that of dobutamine. We intended to know safety and efficacy of arbutamine stress echocardiography in inducing myocardial ischemia and detecting coronary artery disease. METHODS: We underwent arbutamine stress echocardiography on 52 patients, dobutamine stress echocardiography in 35 patients. Alteration of blood pressure, heart rate, regional wall motion on echocardiography were evaluated. Sensitivity and specificity were determined by coronary angiography for 61 patients(Arbutamine: 31, Dobutamine : 30) RESULTS: 1) Hemodynamic alterations respect to stress agents Baseline Maximal Baseline Maximal Interval for Blood pressure Blood pressure Heartrate Heart rate maximal heartrate Arbutamine 122/70mmHg 138/72mmHg 69BPM 137BPM 8.2 min* Dobutamine 126/73mmHg 136/77mmHg 74BPM 102BPM 11.4 min* (* p < 0.05) 2) Comparison of Arbutamine and Dobutamine in sensitivity Sensitivity(Specificity) Side effects Atropine Arbutamine 80.1% (90%) 33(63.5%) 8(15.4%) Dobutamine 78.2% (71.4%) 21(60%) 7(20%) 3) Side effects of stress agents Hypotension Palpitation, tremor Arrhythmia Chest pain Arbutamine 15(28.8%)* 4(7.7%)* 21(40.4%) 8(9.2%) Dobutamine 3(8.6%)* 9(25.7%)* 12(34.3%) 5(5.7%) (* p < 0.05) 4) Premature ventricular contraction was most common arrhythmia in both group. There was no fatal or significant complication, and most complications were subsided after discontinuation of stress agents. CONCLUSION: Arbutamine is an effective and safe pharmacologic stress agent in detecting myocardial ischemia and superior to dobutamine in increasing heart rate. Sensitivity and specificity of arbutamine were higher than that of dobutamine.

Secondary T Wave Changes in Patients with Wolff-Parkinson-White(WPW) Syndrome

OBJECTIVES: The purpose of this study is to evaluate the incidence of secondary T wave changes in WPW syndrome and the relation between the incidence of the secondary T wave changes and sex, age (duration of preexcitation), mean and maximal QRS duration (from the onset of delta wave to the end of S wave) of standard 12 lead electrocardiogram (ECG) and the site of accessory pathway (AP). The secondary purpose of this study is to evaluate the relation between the site of secondary T wave changes and the location of the AP. METHODS: Of the total 128 patients (pts) with WPW syndrome, standard 12 lead ECGs of 125 pts (mean age 35, male 71 pts) who were free from bundle branch block (n=2) and myocardial ischemia (n=1) were analyzed. The locations of Aps were divided into 4 categories (anterior, left lateral, posterior and right lateral) by intracardiac mapping. RESULTS: 82 (66%) pts of 125 pts showed secondary T wave changes. The incidence of secondary T wave changes was not related to sex or duration of preexcitation, but mean QRS duration (<0.12: 46%, 0.12: 88%, p<0.001), maximal QRS duration (<0.12: 32%, 0.12: 73%, p<0.001) and the site of AP (right: 80%, left: 54%, p=0.003). The most frequent lead showing secondary T wave changes in ECG was lateral (lead I, aVL) in pts with anterior (43%, 9 out of 21), posterior (50%, 25 out of 50) and right lateral (86%, 6 out of 7) AP. But, no secondary T wave change was found in most pts with left lateral (n=47) AP. CONCLUSION: The incidence of the secondary T wave changes in pts with WPW syndrome is high (66%). These changes are not related to sex and duration of preexcitation, but to the mean and maximal QRS duration during preexcitation and the location of the AP. The ECG lead showing secondary T wave changes in pts with WPW syndrome appears to be related to the location of the AP and the most frequent lead is I and aVL.

Repolarization Abnormalities after Successful Radiofrequency Catheter Ablation of Accessory Pathway in Patients with the Wolff-Parkinson-White (WPW) Syndrome

BACKGROUND AND OBJECTIVES: The repolarization abnormalities, after radiofrequency catheter ablation (RFCA) of accessory pathway (AP) in patients with Wolff-Parkinson-White (WPW) syndrome, is commonly appeared in standard 12 lead electrocardiogram (ECG) as inverted T waves. We analyzed the serial ECGs after RFCA of AP in patients with WPW syndrome, in order to understand the repolarization abnormalities after RFCA. MATERIALS AND METHOD: The study patients were consisted of ninety two patients (mean age: 35 years old, male: 56 patients) out of 157 patients whose ECGs were taken at before, immediately after, one day, one, four, eight, twelve week (s) after RFCA from December 1992 to July 1997. RESULTS: The seventy three patients (79%) out of ninety two patients showed the repolarization abnormalities and the thirteen patients (14%) showed normalization of secondary T wave changes immediately after RFCA. In contrast, six patients (7%) did not show any T wave changes after RFCA and they had left lateral AP. The lead that most frequently showed inverted T wave changes after RFCA was lateral lead (lead I, aVL) in case of left lateral AP and inferior lead (II, III, aVF) in case of other APs. The incidence of repolarization abnormalities after RFCA was significantly higher in patients whose preRFCA QRS duration is longer (> or =0.12 sec). The concordance rate of repolarization abnormalities after RFCA was 86% (63 patients of 73 patients showing repolarization abnormalities after RFCA). The normalization of repolarization abnormalities after RFCA was acquired in sixty four patients (94%) out of sixty eight patients who showed repolarization abnormalities and followed up to twelve weeks after RFCA. The mean time interval to the normalization of repolarization abnormalities after RFCA was 4.3+/-3.2 weeks. The time interval to the normalization of repolarization abnormality after RFCA was not related with age, AP or preRFCA QRS duration. CONCLUSION: The ECG lead, in which the repolarization abnormalities occurs after RFCA , is related with the location of the AP. The repolarization abnormalities after RFCA were more common in patients with longer preRFCA QRS duration. The repolarization abnormalities after RFCA could not be understood only by cardiac memory.

Clinical Characteristics of Acute Myocardial Infarction Died during Hospitalization

BACKGROUND: Recently, the incidence of acute myocardial infarction (AMI) rapidly increased with prolongation of life spans, improvements of food and life styles in Korea. The mortality rate of AMI is higher than other disease. The purpose of this study is to evaluate which factors can affect the early outcome of AMI in Korean. METHODS: A retrospective clinical study was done on 555 consecutive patients{Male:Female=387 (69.7%):168 (30.3%), mean age 61.3 years} with AMI who had been admitted to Dong-San Medical Center from January 1990 to May 1997 . The subjects were devided into two groups. Group I was dead patients during the in-hospital period (85 patients, 15.3%), and Group II was living patients (470 patients, 84.7%) wen they discharged from hospital. We compared clinical and laboratory results in both groups and analysed the cause of death according to the time of death during hospitalization. RESULTS: The results were as folows; 1) The mean age and female percentage of Group I (65.4 years, 43%) were higher than Group II (60.5 years, 28%). The mean of systolic/diastolic blood pressure and percentage of smoker of Group I (108/65mmHg, 48%) were lower than Group II (125/76mmHg, 65%), significantly. 2) The degree of Killip classification was higher in Group I (class 1:29.4%, II:18.8%, III:21.2%, IV:30.6%) than in Group II patients (class 1:73.4%, II:13.6%, III:8.7%, IV:4.3%), significantly. 3) 47 patients were died first day of hospitalization and the most common cause of death was cardiogenic shock (27 patients, 31%). The most common cause of death within 1 week was cardiogenic shock, afterthen congestive heart failure. 4) The most common cause of death in Killip class I patients was ventricular tachycardia or ventricular fibrillation and in Killip class II-IV patients was cardiogenic shock. CONCLUSION: The risk of in-hospital death was higher in elderly, female sex, and patients with higher killip classification. Cardiogenic shock was most common cause of death within 1 week, and was congestive heart failure after 1 week.

Changes of Echocardiographic Findings after Surgical Correction of Atrial Septal Defect in Adult

BACKGROUND: The aim of surgical treatment for atrial septal defect is correction of anatomical and physiologic anomaly. Incidence of heart failure, cerebrovascular accident, atrial fibrillation and late mortality depend on the timing of surgery. Echocardiographic cardiac functional alteration after surgery is not surveyed sufficiently. So we intended to observe the alteration and function of cardiac anatomy after surgery. METHODS: We studied 22 patients who were undergone correction surgery of atrial septal defect at Keimyung university medical center. We devided patients into two groups according to age. Group I consists of patients who undergone surgery before 41 year old(mean age 32.25 year old, male 3, total 12). Group II comprises patients who undergone surgery after 41 year old(mean age 53.4 year old, male 1, total 10). We compared chief complaint, preoperative cardiac catheterization finding, pre- and post-operative echocardiographic finding(ejection fraction, end diastolic right and left ventricular dimension, grade of tricuspid regurgitation, paradoxical septal motion) between 2 groups. RESULTS: Preoperatively 6 patients(50%) of group I patients were diagnosed as mild congestive heart failure(according to NYHA functional class) and 2 patients(20%) of group II patients were in mild congestive heart failure. The Qp/Qs of both group were 3.5+/-1.7, 2.9+/-1.3, systolic right ventricular pressure were 42.1+/-10.5, 44.5+/-9.5mmHg, systolic pulmonary arterial pressure were 31.3+/-4.3, 36.6+/-7.3mmHg. 1 of group I patients and 2 of group II patients showed ejection fraction below 55% on postoperative echocardiography. The others showed normal ejection on echocardiography. Mean end diastolic right ventricular dimension was 3.84cm preopratively and 2.53cm postoperatively on group II patients. Mean end diastolic right ventricular dimension of group I patients was 3.94cm preoperatively and 2.81cm postoperatively. 3 of group I patients showed mild TR(tricuspid regurgitation), 5 showed moderate TR, and 4 showed severe TR preoperatively. 3 of group I patients showed loss of TR, 1 showed moderate TR, 8 showed mild TR. 3 of group II patients showed mild TR, 2 showed moderate TR, 5 showed severe TR preoperatively. 6 of group II patients showed mild TR, 3 showed moderate TR, 1 showed severe TR postoperatively. Paradoxical septal motion reflects right ventricular pressure overloading and was observed on both groups preoperatively. But after correction surgery, paradoxical septal motion persists at 6(50%) of group I patients, 6(60%) of group II patients. CONCLUSION: Conclusively, surgical correction for atrial septal defect before age of 41 is effective to prevent or slow down the manifestation of congestive heart failure, persistence of TR. Ejection fraction was improved significantly on echocardiography on both groups. But paradoxical septal motion persist after surgery, so more survey is needed.

Clinical Status in Patients Who Restrictive Pattern on Doppler Transmitral Flow Pattern

BACKGROUND: Restrictive pattern on Doppler transmitral flow pattern represent reduced left ventricular compliance and associated with poor prognosis in patients with systolic dysfunction due to congestive heart failure or myocaridal infarction. Although there are many clinical evaluation about clinical significance of restrictive transmitral flow pattern, investigation about what kinds of disease reveal the characteristic restrictive transmitral flow pattern and significance according to criteria of restrictive transmitral flow pattern is few. Therefore, we have analyzed patients with restrictive transmitral flow pattern in order to evaluate clinical diagnosis and clinical significance according to criteria of restrictive transmitral flow pattern. METHODS: The study population consisted of 229 patients(male 129 patients, female 102 patients, mean age 40.6 years old) who show E/A ratio p 2 on Doppler echocardiography from september 1994 to aprial 1996. We have reviewed the medical records of that patients. RESULTS: 1) In case of patients more than 2 at E/A ratio, we found that subjects not related with cardiovascular diseases were 76 persons(33.2%), valvular heart disease 75 patients(32.3%), ischemic heart disease 25 patients(10.9%), cardiomyopathy 16 patients(6.9%). Among valvular heart disease, mitral regurgitation was most frequently observed(44.5%). In these patients, patients with left ventricular systolic dysfunction were 60 patients(26.2%). 2) Patients more than 2 at E/A ratio and less than 150msec at deceleration time of E wave were 126 patients(55.0%). In these patients, we found that valvular heart disease was also most frequently observed(49 patients, 38.8%), subjects not related with cardiovascular diseases 30 persons(23.8%), cardiomyopathy 15 patients(11.9%),pericarditis 7 patients(5.6%), hypertension 3 patients(2-3%). Patients with left ventricular systolic dysfunction in this group were 39 patients(31.0%). CONCLUSION: Although restrictive transmitral flow pattern on Doppler echocardiography represents reduced compliance of left ventricle or severe heart failure in patients with symptoms of congestive heart failure, this pattern also may be seen in persons not related with cardiovascular disease. Therefore, when making dicision about clinical significance of restrictive pattern, one should consider about any factors can influece the transmitral flow pattern and correlate the clinical diagnosis with mitral flow velocity.

Clinical Features and Long-Term Follow-up Results in Fifty Four Patients with Aortic Dissection

BACKGROUND: Aortic dissection is an uncommon disease but early mortality is as high as 1 percent per hour if untreated. However, major advances in the prompt noninvasive diagnosis and in the medical and surgical treatment of aortic dissection now improve the survival rate to an 75~82% of 5-year survival rate. In order to determine clinical features and long-term follow up results of patients with aortic dissection in Korea, we present a retrospective review of 54 patients with aortic dissection at our institute. METHODS: We review the medical records, echocardiograms and computed tomogram(CT) or magnetic resonance imaging(MRI) of 54 patients(mean age: 59+/-12 years, male: 27) who had aortic dissection between September 1991 and July 1997. Patients were classified according to DeBakey type. Clinical features were evaluated in relation to type. Long-term survival rate using Kaplan-Meier method were also evaluated in relation to type, sex and presence of undertaking operation. RESULTS: Of the 54 patients with aortic dissection, twenty two(41%) were classified to type I, eight(15%) to type II and twenty four(44%) to type III. Age(type I: 60 yrs, type II: 60 yrs, type III: 57 yrs), sex(male in type I: 10(45%)type II: 4(50% ), type III: 13(54%)) and pulse rate(type I: 84, type II: 75, type III: 78) according to the type of aortic dissection show no signifiant difference. In regarding to predisposing factors, hypertension was found in 40(74%) overall, Marfan syndrome 1(2%), bicuspid aortic valve 4(7%), and iatrogenic vascular injury 3(6%). Four-year survival rate was 48% in all patients who were followed for 28+/-26 months(1-168 months), 61% in type I, 44% in type II and 44% in the III. But, there are no statistically significant difference in 4-year survival rate according to type and sex or presence of undertaking operation(data not shown). There are many kinds of cause of death; multi-organ failure, renal failure, congestive heart failure, sepsis, ruptured aortic dissection, gastrointestinal bleeding, cerebrovascular disease and postoperative weaning failure in the dead patients from aortic dissection. And also we found that there are some kinds of cause of death not directly related with aortic dissection(sepsis, gastrointestinal bleeding and cerebrovascular disease) in patients, especially in type III. CONCLUSION: Overall four-year survival rate in patients with aortic dissection was 48% and there were no significant differences in survival rate accoring to type, sex and presence of undertaking operation. There were many kinds of cause of death in patients with aortic dissection and some causes of death was not directly related with aortic dissection. The survival rate in patients with aortic dissection will be increased by strict control of blood pressure and optimal timing of operation before development of aortic rupture.

Change of Cardiac Metabolism according to Atrial Pacing

BACKGROUND: In aerometabolic process, the human heart mainly utilizes free acid as fuel. During anaerobic process, lactate production by the myocardium is increased and accumulates in the myocardium. Thus it decreases the contractility of myocadium. Therefore in patients with ischemic heart disease, lactate prodution must be increased by the myocardium during myocardial ischemia. During paroxysmal supraventricular tachycardia, patients frequently experience chest pain and ST segment depression suggesting acute myocardial ischemia. However it occurs on a physiologic basis independent of ischemia. The purpose of this study was to assess whether tachycardia induced by artial pacing produces myocardial ischemia in patients without evidence of ischemic heart disease. METHODS: Between May 28, 1996 and August 13, 1996, at the University of Keimyung, Dong-San Medical center, 15 patients(male 9, female 6, mean age of 38 years) with palpititation underwent electrophysiologic testing and had radiofrequency cather ablation. There were no evidence of ischemic heart disease. Right artrial pacing was done with lengths of 500msec, 400msec and 350msec in each 5 patients. A 12 lead electrdcardiogram, left ventricular enddiastolic pressure, blood from femoral artery and coronary sinus for lactate determinations and blood gas analysis were dbtained simultaneously. They were obtained at baseline, at 1, 5, 10 and 15 minute of atrial pacing and at 1, 5, 10 minute after cessation of pacing. RESULT: Significant changes were not observed in , , concentration of , pH and saturation. In all patients, mean percent lactate extraction was above 10% and not significantly changed during atrial pacing. However ST segment depression was significantly progressive during atrial pacing and according to decrease the cycle length(p<0.05), also left ventricular end-diastolic pressure was significantly decreased during atrial pacing(p<0.05). Conclusion: Therefore tachycardia induced by atrial pacing for 15 minutes did not produce myocardial ischemia in patients without evidence of ischemic heart disease. Depression of STsegment during supraventricular tachycardia or atrial pacing, in patient without underlying heart disease is necessary to inveestigate what makes this phenomenon.