Exercise-Induced Electrocardiography Changes in Pulmonary Arterial Hypertension.

Cardiopulmonary exercise testing (CPET) is an important tool in assessing the functional status of patients with pulmonary arterial hypertension (PAH). During CPET, continuous electrocardiography (ECG) is used as a marker of exercise-induced ischemia or arrhythmia. We hypothesize that ECG changes with exercise may be an early indicator of clinical worsening in PAH and could predict adverse outcomes. Clinical, hemodynamic, and CPET data of 155 children and young adult patients with PAH who underwent CPET between 2012 and 2019 in our pulmonary hypertension (PH) center were included in this retrospective analysis. ECGs were analyzed for ST depressions and T-wave inversions, along with coincident hemodynamic data. These data were correlated with adverse outcomes divided into 2 categories: severe worsening (death or receiving lung transplant) and mild to moderate worsening (PAH medication escalation, hospitalization, shunt creation, or listing for lung transplant). The median age was 19 years (range 7 to 40 years), 69% were female, and the average follow-up time was 5 years (range 1 to 8 years). A total of 63 patients (41%) had at least 1 adverse outcome. A total of 39 patients (25%) demonstrated significant ST-T-wave changes with exercise. Patients with ST-T-wave changes were 20% more likely to die or need lung transplant than those without. The multiple linear regression found that ST-T-wave changes were a predictor of elevated mean pulmonary arterial pressure (mPAP) found on catheterization (R = 0.489, p = 0.003), although not of pulmonary vascular resistance index (R = -0.112, p = 0.484). An mPAP of 55 mm Hg was the most sensitive and specific point in identifying when ST-T-wave changes with exercise begin to appear. In conclusion, ST-T-wave changes on exercise ECG are significantly associated with adverse outcomes in PH in a medium-term follow-up study, and the presence of ST-T-wave changes correlates with higher mPAP. These ECG changes with exercise may be used as early indicators of clinical worsening in PH and predictors of adverse outcomes.

Exercise electrocardiogram for risk-based screening of severe residual coronary lesion in children after coronary surgery.

BACKGROUND: Residual severe coronary artery (CA) lesion (SCL) in children after cardiac surgery involving the CA is a major concern. AIM: To evaluate the value of exercise electrocardiogram (eECG) for risk-based screening of SCL. METHODS: We analysed 135 maximal eECG from 115 children (mean age 13.6±3.7 years) who underwent concomitant CA imaging. SCL was defined as a stenosis exceeding 50%. RESULTS: Underlying congenital heart diseases were transposition of the great arteries (TGA) (n = 116), CA pathway anomaly (n = 13) and left CA from the pulmonary artery (n = 6). Eleven SCLs were identified in 10 patients, of which 3 had a known untreated non-severe lesion and 4 had no lesions on previous imaging. In multivariable analysis, risks markers for SCL were effort chest pain (OR: 4.72, 95% CI: 1.23-18.17; P=0.024), intramural pathway (OR: 4.37, 95% CI: 1.14-16.81; P=0.032). Yacoubs C-type CA was added as a risk marker for patients with TGA (P=0.0009). All patients with SCL had a positive eECG (sensitivity: 100%, 95% CI: 72-100). Specificity was 81% (95% CI: 73-87). In the low-risk group (0 risk markers), 3/95 patients had SCL (3%), and the post-test probability of SCL with positive eECG (PPr+) was 15% (95% CI: 8-21). In the high-risk group (≥1 risk marker) comprising 8/40 SCLs (20%), PPr+ was 53% (95% CI: 35-67). CONCLUSIONS: Most SCL tended to develop gradually, years after surgery. Provided it is near maximal, a negative eECG appears sufficient to exclude SCL. In the high-risk group, PPr+ exceeded 50%.

Exploiting exercise electrocardiography to improve early diagnosis of atrial fibrillation with deep learning neural networks.

Atrial fibrillation (AF) is the most common type of sustained arrhythmia. It results from abnormal irregularities in the electrical performance of the atria, and may cause heart thrombosis, stroke, arterial disease, thromboembolism, and heart failure. Prior to the onset of atrial fibrillation, most people experience atrial cardiomyopathy which, if effectively managed, can be prevented from progressing to atrial fibrillation. Electrocardiogram (ECG) can show changes in the heartbeats, and is a common and painless tool to detect heart problems. P-waves in exercise ECGs change more drastically than those in regular ECG, and are more effective in the detection of atrial myocardial diseases. In this paper, we propose a deep learning system to help clinicians to early detect if a patient has atrial enlargement or fibrillation. Firstly, a Convolutional Recurrent Neural Network is employed to locate the P-waves in the patient's exercise ECGs taken in the exercise ECG test process. Relevant parameters are then calculated from the located P-waves. Then a Parallel Bi-directional Long Short-Term Memory Network is applied to analyze the obtained parameters and make a diagnosis for the patient. With our proposed deep learning system, the changes of P-waves collected in different phases in the exercise ECG test can be analyzed simultaneously to get more stable and accurate results. The system can take data of different length as input, and is also applicable to any number of ECG collections. We conduct various experiments to show the effectiveness of our proposed system. We also show that the more ECG data collected in the exercise phase are involved, the more effective our system is in diagnosis of the diseases.

[Research on the detection algorithm of electrocardiogram characteristic wave based on energy segmentation and stationary wavelet transform].

The detection of electrocardiogram (ECG) characteristic wave is the basis of cardiovascular disease analysis and heart rate variability analysis. In order to solve the problems of low detection accuracy and poor real-time performance of ECG signal in the state of motion, this paper proposes a detection algorithm based on segmentation energy and stationary wavelet transform (SWT). Firstly, the energy of ECG signal is calculated by segmenting, and the energy candidate peak is obtained after moving average to detect QRS complex. Secondly, the QRS amplitude is set to zero and the fifth component of SWT is used to locate P wave and T wave. The experimental results show that compared with other algorithms, the algorithm in this paper has high accuracy in detecting QRS complex in different motion states. It only takes 0.22 s to detect QSR complex of a 30-minute ECG record, and the real-time performance is improved obviously. On the basis of QRS complex detection, the accuracy of P wave and T wave detection is higher than 95%. The results show that this method can improve the efficiency of ECG signal detection, and provide a new method for real-time ECG signal classification and cardiovascular disease diagnosis.

Research on the detection algorithm of electrocardiogram characteristic wave based on energy segmentation and stationary wavelet transform / 生物医学工程学杂志

The detection of electrocardiogram (ECG) characteristic wave is the basis of cardiovascular disease analysis and heart rate variability analysis. In order to solve the problems of low detection accuracy and poor real-time performance of ECG signal in the state of motion, this paper proposes a detection algorithm based on segmentation energy and stationary wavelet transform (SWT). Firstly, the energy of ECG signal is calculated by segmenting, and the energy candidate peak is obtained after moving average to detect QRS complex. Secondly, the QRS amplitude is set to zero and the fifth component of SWT is used to locate P wave and T wave. The experimental results show that compared with other algorithms, the algorithm in this paper has high accuracy in detecting QRS complex in different motion states. It only takes 0.22 s to detect QSR complex of a 30-minute ECG record, and the real-time performance is improved obviously. On the basis of QRS complex detection, the accuracy of P wave and T wave detection is higher than 95%. The results show that this method can improve the efficiency of ECG signal detection, and provide a new method for real-time ECG signal classification and cardiovascular disease diagnosis.

Added value of exercise test findings beyond traditional risk factors for cardiovascular risk stratification.

BACKGROUND: Functional aerobic capacity (FAC) determined by treadmill exercise testing (TMET) is associated with cardiovascular (CV) disease mortality independent of traditional CV risk factors and is a potentially underutilized tool. The purpose of this study was to determine added prognostic value of reduced FAC and other exercise test abnormalities beyond CV risk factors for predicting total and CV mortality. METHODS: The TMET database was queried for Minnesota patients (≥30 years) without baseline CV disease from September 21, 1993, through December 20, 2010. Risk factors and exercise abnormalities including low FAC (<80% predicted), abnormal heart rate recovery (<13 bpm), and abnormal electrocardiogram (ST depression ≥1 mm regardless of baseline) were extracted. Mortality data were obtained through February 2016. Patients were divided into 9 groups by abnormality number (0, 1, or ≥2) and risk factors (0, 1, or ≥2). Cox regression was used to determine mortality risk according to exercise abnormalities/CV risk factors, adjusted for age and sex. RESULTS: 19,551 patients met inclusion criteria; 1271 (6.5%) died over 12.4 ±â€¯5.0 years' follow-up (405 [32%] CV deaths). Exercise abnormalities significantly modified risk for every number of CV risk factors. Hazard ratios (95% CI) for total mortality (0 vs ≥2 abnormalities) were 2.4 (1.9-2.9; P < .001) for 0 CV risk factors; 2.7 (2.2-3.3; P < .001), 1 risk factor; and 6.1 (4.8-7.7; P < .001), ≥2 risk factors. Similar results were noted for CV disease mortality. CONCLUSIONS: Exercise test abnormalities strongly predict mortality beyond traditional CV risk factors. Our results indicate that TMET should be considered for CV risk assessment.

Left main coronary artery atresia in a child: a case report and review of the literature.

Congenital atresia of the left coronary artery is a very rare condition. We report a case of a 13-year-old boy who was followed-up at our outpatient clinic from 6 months of age because of heart murmur. He had no symptoms for more than 10 years, and his left ventricular contraction was normal. Exercise electrocardiogram was performed at 7 and 10 years of age, and ST depression was not observed. He presented with chest pain and syncope on exertion at the ages of 11 and 12 years, respectively, and ST depression on exercise electrocardiogram was detected for the first time at 13 years of age. Cardiac echocardiography showed a high-choic antero-lateral papillary muscle of the mitral valve, prolapse of the mitral anterior leaflet, and mild mitral valve regurgitation. Coronary angiography did not demonstrate antegrade left coronary flow or dilation of the right coronary artery. We performed coronary artery bypass grafting using the left internal thoracic artery. Postoperatively, the ST depression resolved, and his exercise tolerability improved.

Electrocardiographic and scintigraphic evaluation of patients with subclinical hyperthyroidism during workout.

Subclinical hyperthyroidism (sHT) was found to be associated with elevated heart rate, blood pressure and increased risk of extrasystoles. However, the full clinical relevance of morphological and functional implications of sHT on the cardiovascular system is still a matter of debate. The aim of the study was to prospectively assess the influence of endogenous sHT on exercise capacity and cardiac function during workout with the use of exercise electrocardiography (ExECG) and perfusion scintigraphy. The studied group consisted of 44 consecutively recruited patients diagnosed with sHT. In all patients, ExECG, followed by post-exercise myocardial perfusion imaging, was performed. Both ExECG and scintigraphy were performed twice-in the state of sHT and after euthyroidism was restored. An average time period of exercise test was significantly longer in the state of euthyroidism than in sHT. An average oxygen consumption during exercise test was also higher after euthyroidism was achieved when compared to sHT. The end-diastolic and end-systolic volume indexes, stroke volume index and cardiac index were significantly larger in patients with sHT if compared values achieved after euthyroidism restoration. Stroke volume index was negatively correlated with TSH, and positively with free thyroid hormones values in the state of sHT, before euthyroidism was achieved. Cardiac index was positively correlated with free thyroid hormones levels. The obtained results indicate worse physical capacity in subjects with sHT and improvement of several parameters assessed during ExECG and perfusion scintiscan after therapy. Observed changes might reflect the mechanism of the deleterious effect exerted by sHT on the heart.

Long-Term Clinical Impact of Coronary CT Angiography in Patients With Recent Acute-Onset Chest Pain: The Randomized Controlled CATCH Trial.

OBJECTIVES: The aim of the CATCH (CArdiac cT in the treatment of acute CHest pain) trial was to investigate the long-term clinical impact of a coronary computed tomographic angiography (CTA)-guided treatment strategy in patients with recent acute-onset chest pain compared to standard care. BACKGROUND: The prognostic implications of a coronary CTA-guided treatment strategy have not been compared in a randomized fashion to standard care in patients referred for acute-onset chest pain. METHODS: Patients with acute chest pain but normal electrocardiograms and troponin values were randomized to treatment guided by either coronary CTA or standard care (bicycle exercise electrocardiogram or myocardial perfusion imaging). In the coronary CTA-guided group, a functional test was included in cases of nondiagnostic coronary CTA images or coronary stenoses of borderline severity. The primary endpoint was a composite of cardiac death, myocardial infarction (MI), hospitalization for unstable angina pectoris (UAP), late symptom-driven revascularizations, and readmission for chest pain. RESULTS: We randomized 299 patients to coronary CTA-guided strategy and 301 to standard care. After inclusion, 24 patients withdrew their consent. The median (interquartile range) follow-up duration was 18.7 (range 16.8 to 20.1) months. In the coronary CTA-guided group, 30 patients (11%) had a primary endpoint versus 47 patients (16%) in the standard care group (p = 0.04; hazard ratio [HR]: 0.62 [95% confidence interval: 0.40 to 0.98]). A major adverse cardiac event (cardiac death, MI, hospitalization for UAP, and late symptom-driven revascularization) was observed in 5 patients (2 MIs, 3 UAPs) in the coronary CTA-guided group versus 14 patients (1 cardiac death, 7 MIs, 5 UAPs, 1 late symptom-driven revascularization) in the standard care group (p = 0.04; HR: 0.36 [95% CI: 0.16 to 0.95]). Differences in cardiac death and MI (8 vs. 2) were insignificant (p = 0.06). CONCLUSIONS: A coronary CTA-guided treatment strategy appears to improve clinical outcome in patients with recent acute-onset chest pain and normal electrocardiograms and troponin values compared to standard care with a functional test. (Cardiac-CT in the Treatment of Acute Chest Pain [CATCH]; NCT01534000).

Efficacy of multi-detector coronary computed tomography angiography in comparison with exercise electrocardiogram in the triage of patients of low risk acute chest pain.

OBJECTIVES: To compare the safety and diagnostic efficacy of coronary computed tomography angiography (CTA) with exercise electrocardiography (XECG) in triaging patients of low risk acute chest pain. BACKGROUND: Noninvasive assessment of coronary stenosis by CTA may improve early and accurate triage of patients presenting with acute chest pain to the emergency department (ED). METHODS: Low risk patients of possible acute coronary syndrome (ACS) were included in the study. The patients in CTA arm with significant stenosis (≥ 50%) underwent catheterization, while those with no or intermediate stenosis (<50%) were discharged from ED and followed up periodically for six months for major adverse cardiovascular events (MACE). The same protocol was applied for XECG arm. Outcomes included: safety and diagnostic efficacy. RESULTS: A total of 81 (41 CTA and 40 XECG) patients were enrolled. In this study CTA was observed to be 100% sensitive and 95.7% specific in diagnosing MACE in low risk patients of chest pain presenting to the ED, with a PPV of 94.7% and an NPV of 100%.The overall diagnostic efficacy was 97.6%. XECG was observed to be 72.7% sensitive and 96.6% specific in diagnosing MACE with a PPV of 88.9% and NPV of 90.3% in low risk chest pain patients presenting to the ED. The overall diagnostic accuracy was 90%. CONCLUSION: CTA is an excellent diagnostic tool in ED patients with low risk of ACS, with minimum time delay as compared to XECG, and also is safe for triaging such patients.

Utility of the exercise electrocardiogram testing in sudden cardiac death risk stratification.

BACKGROUND: Sudden cardiac death (SCD) remains a major public health problem. Current established criteria identifying those at risk of sudden arrhythmic death, and likely to benefit from implantable cardioverter defibrillators (ICDs), are neither sensitive nor specific. Exercise electrocardiogram (ECG) testing was traditionally used for information concerning patients' symptoms, exercise capacity, cardiovascular function, myocardial ischemia detection, and hemodynamic responses during activity in patients with hypertrophic cardiomyopathy. METHODS: We conducted a systematic review of MEDLINE on the utility of exercise ECG testing in SCD risk stratification. RESULTS: Exercise testing can unmask suspected primary electrical diseases in certain patients (catecholaminergic polymorphic ventricular tachycardia or concealed long QT syndrome) and can be effectively utilized to risk stratify patients at an increased (such as early repolarization syndrome and Brugada syndrome) or decreased risk of SCD, such as the loss of preexcitation on exercise testing in asymptomatic Wolff-Parkinson-White syndrome. CONCLUSIONS: Exercise ECG testing helps in SCD risk stratification in patients with and without arrhythmogenic hereditary syndromes.

Does ST-segment depression combined with R wave amplitude change improve the test accuracy of the EKG during exercise testing? / 대한내과학회지

BACKGROUND: Exercise electrocardiogram is the most widely used non-invasive test in those patients suspected of having coronary artery disease. However, sensitivity and specificity of this test are not satisfactory, especially when the exercise induced ST-segment depression is used as a single criterion of myocardial ischemia. Although many investigators have tried to improve diagnostic accuracy with R-wave amplitude change in addition to ST-segment depression, controversy exists whether this new criteria improve the test accuracy for coronary artery disease or not. The purpose of this study is to determine the test accuracy of R-wave amplitude change induced by exercise combined with the conventional ST-segment criterion for myocardial ischemia. METHODS: We reviewed our records of patients who visited to Korea University Anam Hospital with chest pain from January, 1998 to July, 1999. We included 130 patients with chest pain who had a tredmill test followed by a coronary angiography within 2 months. Patients with change in ST-segment depression (delta STD)> or = 1.00 mm and delta STD> or = 1.00 mm with R wave amplitude decrease (-delta R)> or = 1.00 mm in the same lead in any of 12 leads and delta STD> or = 1.00 mm with R wave amplitude increase (+delta R)> or = 1.00 mm in the same lead in any of 12 leads were compared. According to the findings of coronary angiograms, patients were divided into 4 groups ; normal coronary artery group, mild coronary artery stenosis group (> or = 30% to or = 50% to or = 70%). RESULTS: Fifty three patients (40.7%) had normal coronary angiograms and 77 patients (59.3%) had coronary artery stenosis. There was no significant difference in gender and age. But, patients with coronary artery stenosis had more diabetes mellitus, hyperlipidemia, smoking, previous myocardial infarction history and angina during exercise testing than those without coronary artery stenosis. The sensitivity of exercise EKG is significantly decreased when combined with delta R (delta STD, 74.0%, delta STD with -delta R, 45.5%, delta STD with +delta R, 30.0%, p<0.01), but the The test accuracy is delta STD; 73.7%, delta STD with -delta R; 61.5%, delta STD with +delta R; 57.7%. CONCLUSION: When ST-segment depression is combined with R-wave amplitude change as a marker for myocardial ischemia, the specificity is increased, but the test accuracy of exercise EKG is not improved.

Diagnostic Value of QT and JT Dispersion in Exercise ECG

BACKGROUND: QT dispersion(QTD : QTmax-QTmin) or JT dispersion(JTD:JTmax-JT-min)in 12 leads ECG has been known to reflect regional variations in ventricular repolarization and has been reported to bel one of the marker of regional myocardial ischemia. To evaluate the significance of QTD or JTD of exercise ECG in diagnosis of coronary artery disease, we studied 106 patients(mean age, 56.9 years old, male 63) who were referred for the evaluation of chest pain on exertion. METHOD: Treadmill exercise stress test with modified Bruce protocol and coronary angiography were performed in 106 patients with chest pain on exertion. ST-segment depression by >1.0 mm 0.08 second after J-point during or after exercise in exercise test and >50% stanosis of epicardial artery in coronary angiogram were defined as positive. Of 106 patients, 41 had positive exercise ECG and positive coronary angiogram(true positive, TP), 20 had positive exercise ECG and negative coronary angiogram(false positive, FT), 20 had negative exercise ECG and positive coronary angiogram(faalse negative, FN), and 23 had negative exercise ECG and negative coronary angiogram(true negative, Tn). QT and JT interval in 12 leads were measured at baseline and peakexercise and were corrected for heart rate using Bazett's formula. QTD and JTD were measured by calculation the difference between the maximum QT and mininum QT and that between maximum JT and minumum JT. RESULTS: QTD at baseline for TP(72.8ms)was prolonged compared to Tn(52.2ms,P<0.01), but was not different from that for FT(70.2 ms). At peak exercise, QTD for TP(81.3 msec) was significantly prolonged(p<0.01), while QTD for FP(71.2 msec) was not different from that for TN(56.8 msec). JTD at baseline(78.4 msec) and at peak exercise(88.2 msec) for TP were significantly prolonged compared to those for TN(55.2msec and 55.1msec p<0.01,p<0.01, respectively), but those for FP were not porlonged(77.0msec and 79.0msec, respectively). QTD and JTD at peak exercise were more markedly prolonged in patients with sever stenosis of coronary artery(p=0.053 and p<0.05, repectively) and multivessels diseases(p<0.01, 0<0.05) than those with less severe disease and single vessel disease. Patients with left anterior descending artery lesion had greater QTD and JTD at peak exercise than those with other vessels lesion(p<0.01). In addition to standard criteria with ST segment displacement in exercise EGC, inclusion of exercise induced QTD of more than 60msec increased the sensitivity of exercise ECG from 66.7% to 83.3%, and JTD of more than 70msec increased the specificity from 52% to 76.0%. CONCLUSION: Measurement of QT dispersion and JT dispersion of exercise ECG may be useful method to identify the severity of coronary artery disease and to improve diagnostic accuracy of exercise ECG in coronary artery disease.

The Prognostic Value of DeltaST/HR Index and Rate-Recovery Loop during Predischarge Exercise Test in Acute Myocardial Infarction

BACKGROUND: The heart rate adjusted ST segment criteria(Delta ST/HR index and rate-recovery loop or R-R loop) compared to standard ST segment criteria may improve the ability of the exercise electrocardiogram for the prediction of severe coronary artery disease and future cardiac events in patients with chronic angina pectoris, but the predictive value of these criteria for predicting these issues has not been studied in patients with acute myocardial infarction. METHODS: 64 patients with first uncomplicated myocardial infarction were studied. All patients performed predischarge(mean 8+/-4 days) symptom-limited exercise test and coronary angiography(mean 11+/-15 days). During the follow-up period(mean 449+/-273 days), the occurrence of the major cardiac events(death, reinfarction, coronary artery bypass surgery) and minor cardiac event(angina, heart failure) were recorded, and then univariate and multivariate analysis of several clinical and exercise variables known to be as prognostic markers were performed. RESULTS: The results are as follows : 1) The sensitivities of Delta ST/HR index and R-R loop(92%, 83% respectively) for predicting multivessel disease showed no significant difference compared to that of standard ST segment criteria(83%). 2) Major cardiac events occurred in 12(20%) of 64 patients and only single independent predictive factor for its prediction was multivessel coronary artery disease(p=0.0001), whereas total cardiac event occurred in 32(50%), multivessel disease(p=0.003), and maximal workload <5mets(p=0.038). 3) For the prediction of total cardiac event, DeltaST/HR index and R-R loop(all 97%) were significantly more sensitive(p<0.05) than standard ST segment criteria(78%), and there was a tendency to increase in specificity in R-R loop(84%) compared to DeltaST/HR index(59%) or standard ST segment criteria(66%). 4) The negative predictive value of all negative test of three ST segment criteria for predicting total cardiac event was 100%. CONCLUSION: Although the heart rate-adjusted ST segment criteria have no advantage over standand ST segment criteria for the prediction of severe coronary artery disease, they can be more useful prognostic markers by enhancing the accuracy of the predischarge exercise electrocardiogram for the prediction of subsequent cardiac events after a first acute myocardial infarction.

ST Segment Change on Treadmill Exercise Electrocardiogram and Coronary Arteriographic Findings in Patients with Angina Pectoris

Although exercise electrocardiography is commonly used to determine the likelihood of coronary artery disease, data of exercise electrocardiography are limited in Korea. Authors reviewed 409 patients with chest pain who underwent 12 lead treadmill exercise electrocardiography and coronary arteriography at Seoul National University Hospital from January, 1984 through September, 1990. All the patients underwent catheterization within three months after having a standard Bruce protocol treadmill exercise test. None of them had prior myocardial infarction, valvular heart disease, cardiomyopathy, and complete left bundle branch block. The study subjects consisted of 208 patients, including 42 patients of coronary artery spasm, with no or insignificant fixed coronary artery stenosis(less than 50% narrowing of luminal diameter), and 201 with significant fixed stenosis. The results were as follows; 1) The sensitivity of treadmill exercise electrocardiography was 73.6%, and the specificity was 88.2%. Positive exercise test in coronary artery spasm was 21.4%. 2) With increasing the extent of coronary artery disease, the proportion of the patients with one-vessel disease who showed positive ST segment change of stage I increase. Most of the patients with one-vessel disease who showed positive ST segment change on stage I had 90% or more stenosis. 3) With increasing the extent of coronary artery disease, the proportion of the patients with positive ST segment change in multiple lead groups increased. 4) ST segment change appeared most frequently in lead group V4-V6 and next in lead group II III a VF regardless of involved arteries. 5) ST segment elevation in lead group V1-V3 or in I/aVL was usually associated with 90% or more stenosis of left anterior descending artery in one-vessel disease, but similar proportion of the patients was noted in multivessel disease. This suggests that ST segment elevation in lead group V1-V3 or in I/aVL is probably associated with severe ischemia, not a specific predictor of left anterior descending coronary artery disease.