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Objective To systematically evaluate the diagnostic value of treadmill exercise test (TET) compared with dynamic electrocardiography (DCG). Methods Databases including Cochrane library, MEDLINE,EMbase,Google Scholar and CNKI were retrieved to collect randomized clinical trials (RCT) and controlled clinical trials(CCT)focusing on comparison of TET and DCG. After screening according to the inclusion and exclusion criteria,all articles received Jadad quality assessment,and were analyzed using Review Manager Version 5.3 software(The Cochrane Collaboration,Oxford,United Kingdom). Results 9 papers with a total of 667 patients who underwent coronary angiography(CAG),TET and DCG were eventually enrolled. Results of the present Meta?analysis were as below.(1)Sensitivity:9 trials(n = 552)suggested that the sensitivity is 80.62% in TET Group versus 72.64%in DCG Group[RR=1.11,95%CI(1.04~1.18),P=0.002]. The difference was statistically significant.(2)Specificity:7 trails(n=126)indicated that no statistical significance[RR=0.86,95%CI(0.71~1.04),P=0.11]was found in specificity when comparing TET(68/115)and DCG(87/126). Conclusion TET has higher sensitivity but similar specificity in comparison with DCG,and it turns out to be a simple and feasible inspecting method in diagnosing coronary heart disease.
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Objective To study the influencing factors on the false negative of electrocardiogram tread?mill exercise test.Methods One hundred and seventy cases coronary heart disease( CHD) patients with coro?nary angiography and carried out electrocardiogram treadmill exercise test from January 2012 to June 2015 in Cardiology Department of the People’ s Hospital of Yanchang County were selected as research objects,including 80 cases of false negative and 90 of positive.The clinical data of two groups were analyzed retrospectively.Results (1)Single factor analysis:CAG results in the false negative group showed that there were 54 cases(67.50%) of single vessel stenosis,14 cases(17.50%) of two vessel stenosis,12 cases(15.00%) of three vessel stenosis,in positive group there were 48 cases(53.33%),34 cases(37.78%) and 8 cases(8.89%) respectively,the differ?ences between the two groups was significant(χ2=8.93,P<0.05).The ST segment of the coronary artery stenosis in the false negative group was 19 cases(23.75%),83 cases (92.22%) in the positive group.There were 61 ca?ses (76.25%) and 7 cases(7.78%) with good collateral circulation in the coronary artery of the two groups,re?spectively,the difference between the two groups was significant(χ2=82.74,P<0.01).There were significant differences in terms of left anterior descending artery(LCX),left anterior descending branch(LAD),left main trunk(LM) diameter between the two groups((3.58±0.95) mm vs. (3.47±0.15) mm,(4.25±0.11) mm vs. (3.94±0.17) mm,(4.58±0.37) mm vs. (4.37±0.26) mm;t=2.91,6.80,2.06;P<0.05).(2)Considering false negative and positive as a dependent variable,and items with significance level including the number of narrow blood vessels,the diameter of coronary artery,LCX,LAD and LM diameters as independent variables in the sin?gle factor analysis,logistic regression analysis was carried out to find that LAD had significant difference in diam?eter,which was independent risk factor for the development of electrocardiogram exercise test false negatives( OR=16.95,95%CI 3.58-80.27,P<0.01).Conclusion False negative is associated with coronary artery diameter for coronary heart disease patients after electrocardiogram treadmill exercise test.The wider coronary diameter is, the easier to produce false negative results in exercise treadmill test.
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Background: With the advent of remote culture, we are becoming physically inactive and becoming prone to cardiovascular disease. Exercise is often used to evaluate the function of cardiovascular system. Objectives: The study aimed to assess the cardiovascular response to exercise in young healthy medical students. Materials and methods: On the basis of physical activity performed subject were categorized into 3 category light, moderate, vigorous exerciser. Cardiovascular response was assessed by using treadmill exercise as per bruce protocol. Pulse rate, B.P., E.C.G were recorded before and after undergoing the treadmill test. Results: Data were analyzed using the paired t-test. The resting heart rate and systolic blood pressure was significantly lower in vigorous group of exerciser. During exercise heart rate, B.P. increased significantly during peak of exercise and recovery occurs within 6 min but recovery was faster in vigorous group of exerciser. Conclusion: It was observed in the study that vigorous exerciser had better parasympathetic tone than moderate and light exerciser.
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Objective To discuss the value of Duke treadmill score in the diagnosis of coronary heart disease.Methods 94 inpatients underwent treadmill test and coronary angiography,the relationship between the Duke treadmill score and the results of coronary angiography was analyzed.Results The prognostic accuracy and positive predictive value of Duke treadmill score to male and female were 88.9％,85.0％ ;those of traditional electrocardiogram ST standard were 89.6％,82.5 ％,the differences were significant (x2 =4.27,P ＜ 0.05).Conclusion The Duke treadmill score is much more significant than the traditional ST standard in the prognostic accuracy and positive predictive value of diagnosing coronary heart disease.
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Objective To investigate the clinical significance of the ST segment changing in treadmill exercise test positive for the diagnosis of coronary heart disease. Methods 133 patients (hospitalized from January 2014 to January 2015) with the ST segment depression≥0.1 mm in treadmill exercise test were retrospectively analyzed. Patients were divided into the observation group and the control group according to the coronary angiography (the dividing line is artery stenosis is more than 50% or not ). ST-segment depression margin and recovery time of the two groups were compared. ST-segment depression margin and recovery time of patients with different vascular lesion number were also analyzed. Results In 133 cases, 79 cases of coronary angiography were positive(59.4%). Positive rate of ST segment recovery time(> 90 s) was 76.9% in. The maximal ST-segment depression margin and recovery time in the observation group were more than the control group, the difference was statistically significant (P 0.05). But in terms of ST-segment recovery time, the double-vessel and multivessel stenosis group were higher than the single-vessel stenosis group , and the difference was statistically significant (P< 0.05). Conclusion Clinically, patients with TET positive combined the ST segment depression and ST-segment recovery time are important hints for the diagnosis of coronary artery disease , and is worthy of promotion.
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Objective To observe the clinical significance and variation of plasma B-type brain natriuretic peptide (△BNP) levels before and after treadmill exercise test (TET) in women with coronary heart disease(CHD). Methods Sixty-one women with suspected coronary heart disease were selected (except for heart failure, blood BNP levels were normal). All patients underwent coronary angiography, were divided into two groups, 25 cases in normal group and 36 cases in coronary heart disease group. Plasma BNP levels were measured before and after the TET test, and data were compared between two groups after one week.Furthermore, the levels of△BNP before and after TET in patients with different degrees of coronary artery lesions were compared. The diagnostic value of the levels of△BNP in coronary heart disease was evaluated by the re-ceiver operating characteristic curve (ROC). Results The plasma BNP level was significantly increased after TET (44.20± 14.53) than that before the test (32.82±10.72) in coronary heart disease group (P<0.01). There were significant differences in levels of△BNP before and after TET in patients with different degrees of coronary lesions. The levels of△BNP were sig-nificantly higher in multi-vessel disease group than those of single and double lesion group (P<0.05). The level of△BNP was significantly higher in double lesion group than that of single lesion group (P < 0.05). When the level of △BNP=7.3 ng/L, the sensibility value and specificity value for the diagnosis of CHD was 82.4%and 81.5%. The area under curve (AUC) was 0.900, and 95%confidence interval was 0.796-0.962. Conclusion The detection of△BNP before and after TET has an important clinical significance in the diagnosis and evaluation of coronary heart disease in women patients.
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Objective To investigate the significance of treadmill exercise test in male patients with coronary heart disease.Methods Two hundred and twenty-four male patients who diagnosed as coronary heart disease by coronary angiography were enrolled in this study,and treadmill exercise test were performed before and 1 month after coronary angiography.The coronary artery stenosis degree and scope were compared between two methods.Results In coronary angiography of 224 patients,the positive was 171 patients and negative was 53 patients.The single stenosis,double stenosis and triple stenosis was 87,55,29 patients.In treadmill exercise test of 224 patients,the positive was 143 patients and negative was 81 patients.The sensibility of treadmill exercise test compared the standard of coronary angiography was 81.3％,positive predictive value was 97.2％.Meanwhile in patients combined with hypertension or diabetic,treadmill exercise test found that the ST segment depression appeared earlier,persistence time longer.The persistence time and the number of down lead in double stenosis and triple stenosis was higher than that in single stenosis.Conclusion Treadmill exercise test is an important method in the diagnosis of coronary artery disease,and can preliminarily estimate the extent of coronary artery stenosis.
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Objective To explore the relationship between body mass index(BMI) and blood lipid,physical activity,blood pressure and electrocardiagram(ECG) lead V1 P wave terminal force(PTFv1).Methods A total of 1 548 heahy volunteers with no diabetes,cardiovascular disease and hypertension were assigned to the normal control,overweight or obese groups.The correlation between BMI and lipid profiles was analyzed.One hundred and ninty-five volunteers without exercise-induced asthma and emergency were required to do treadmill exercise test to analyze the correlation between physical activity score,blood maximum pressure and Ptfv1.Results BMI was significantly different by blood lipid (Cholesterol:F=7.57,P＜0.05; Triglyceride:F=73.40,P＜0.05),physical activity score(F=4.52,P＜0.05) and blood maximum pressure(F=1 1.75,P＜0.05) other than age(P＞0.05).In the three groups,treadmill exercise test was significantly different in Ptfv1(normal control group vs obese group:x2=5.67,P＜0.05; overweight group vs obese group:x2=6.17,P＜0.05).Conclusion With the increase of BMI,blood lipid and maximal systolic pressure were increased,although physical activity score was decreasing.Abnormal PTFv1 was significantly associated with BMI.increased Treadmill exercise test may be helpful in screening potential cardiovascular disease among high risk obesity populations.
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Objective To observe the relationship between short-term heart rate variability(HRV) and heart rate recovery (HRR) after exercise.Methods 495 patients (273 men),whose age ranged 19-85 years,were submitted to treadmill exercise tests and short-term HRV evaluations.The standard deviation of the normal-to-normal interval (SDNN),the square root of the mean squared differences of successive normal-to-normal intervals (RMSSD),the number of interval differences of successive normal-to-normal intervals greater than 50 ms (NN50 count),the proportion derived by dividing NN50 count by the total number of normal-to-normal intervals (pNN50) and frequency(lowfrequency power,high-frequency power,total power) domains were observed.Results Among 495 patients,106 patients(68 men) were elderly(age≥65 years).Male gender and hypertension were significantly higher in elderly patients.The young patients had higher HRR after exercise.HRR at 4min (54 ± 13) vs (60 ± 12) beats/min,P =0.003 was the most significant predictor for positive exercise test result.In the young group,both time domain measures (SDNN:correlation coefficient 0.34,P ＜ 0.001 ; RMSSD:correlation coefficient 0.37,P ＜ 0.001) and frequency domain measures (LF:correlation coefficient 0.21,P ＜ 0.001 ; HF:correlation coefficient 0.13,P =0.01 ; total power:correlation coefficient 0.22,P ＜ 0.001) were significantly associated with HRR at 4min.Conclusion HRR at 4min was significantly associated with short-term HRV of time and frequency domains in young individuals,but not elderly ones,who received treadmill exercise test.
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The study aims to assess the cardiovascular response to treadmill exercise test in healthy Indian adolescents. A group of 50 healthy adolescents took part in the study. Cardiovascular response was assessed by using treadmill exercise test as per Bruce protocol. Pulse rate, blood pressure and ECG were recorded before, during and after undertaking the treadmill test. Mean age and body mass index (BMI) were 18.7±0.51 yrs. and 21.4±3.44 kg/m2 respectively. Karl Pearson Correlation analysis showed highly significant negative correlation between BMI and exercise time (r = –0.598, P<0.001) and between resting DBP and Exercise Time (r = –0.424, P<0.002). While BMI and DBP showed highly significant positive correlation (r = 0.463, P<0.001). During exercise pulse and SBP rose and DBP fell. SBP rose from mean 122 to 175 (rise by 53 mm of Hg) and DBP fell from mean 78 to 65 (fall by 13 mm of Hg). One min recovery pulse was 156 indicating 22% fall from target heart rate. All the parameters returned to near resting value at 6 min recovery. In 30% students DBP showed exaggerated response i.e. rise during exercise. These students had more BMI and higher resting DBP as compared to other students, which could be the reason for exaggerated response in these participants. In ECG there were no significant ST/T changes during exercise or recovery period. This study provides normal data for small sample of healthy Indian adolescents when subjected to treadmill exercise test.
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Objective To determine the diagnostic value of the change of different parts of electrocardiogram in treadmill exercise test (TET) for coronary heart disease (CHD).MethodsFrom Jan.2006 to Mar.2011,445 patients with CHD underwent treadmill exercise test and coronary angiography (CAG) in our hospital.We analyzed retrospectively the diagnostic value of the change of different parts of electrocardiogram in TET test.Results ( 1 ) There were 200 cases who had positive results during treadmill exercise test and 150 cases of them had been diagnosed of CHD by coronary angiography;The other 245 cases had negative results during treadmill exercise test and 39 cases of them had been diagnosed as CHD by coronary angiography.The sensitivity and specificity rates of treadmill exercise test in diagnosis of CHD were 79.36％( 150/189 ) and 80.47％ ( 206/256 ) respectively. ( 2 ) Of the 200 positive cases tested by coronary angiography,150 cases were diagnosed of CHD,including 22,58 and 70 cases with limb,chest and combined chest and limb leads positive results respectively.The positive rates for the groups of combined chest and limb leads and limb ST leads were significantly higher than that of the chest leads only group ( x2:6.34,3.93 ; P ＜0.05).(3)R wave amplitude of the CAG negative group after exercise (17.54 ± 2.52)mm was significantly lower than the CAG positive group ( 19.42 ± 3.46 )mm ( t =6.33,P ＜ 0.05 ).( 4 ) For the 200 cases with positive TET,there were no significant statistical difference ( P ＞ 0.05 ) on CAG positive rate between T wave normalization group [ 73.3％ (44/60) ] with and TET positive group [ 75.0％ (105/140) ].But these two groups had significantly higher ( x2:80.21,132.82 ; P ＜ 0.05 ) CAG positive rates than TET negative group [ 15.9％ (39/245) ].ConclusionThe treadmill exercise test is valuable in noninvasive diagnosis of CHD.The severity of CAG can be preliminarily estimated by analyzing the pattern of the change of different parts of electrocardiogram
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Objective To investigate the clinical significance of treadmill exercise test in the diagnosis of coronary artery disease. Methods137 patients with chest pain,chest distress and palmus but without the change of ECG were selected.Treadmill exercise test was used. Results78 patients were positive and the positive rate was 56.9%,while the negative rate was 43.1%. ConclusionTreadmill exercise test could improve the diagnosis rate and sensitivity rate of coronary artery disease.It plays an important clinical significance in the diagnosis and treatment of coronary artery disease.
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Objective To investigate the clinical characteristics of the results of coronary artery CT angiography and coronary artery angiography in 36 patients with probable positive results of treadmill exercise test(TET).Methods Thirty-six patients due to chest pain received 1ET and coronary artery CT angiography and coronary artery angiography in 2 weeks after admission.The coronary plaques were categorized as noncalcified and calcified plaque on CTA images.Results In 36 patients with probable positive results of TET.23 patients were confirmed as coronary artery disease by coronary artery angiography,and the other 13patients had normal coronary artery.Of 23 coronary artery disease patients,9 patients were presented as onevessel disease,5 patients were presented as two-vessel disease,and 9 patients were presented as three-vessel disease,29 non-calcified plaques and 23 calcified plaques were demeted On CTA.Conclusion TET was useful in confirming the diagnosis of coronary artery disease.The characteristics of the coronary artery plaque is correlated with probable positive results of TET.
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Objective To discuss the value of systolic blood pressure during recovery rate using treadmill exercise test to diagnose coronary heart disease.Methods A total of 88 patients underwent treadmill test and coronary angiography within 2 weeks,and the relativity was analysed between the third minute systolic blood pressure(3SBP)during recovery rate and the results of coronary angiography.Results The sensitivity、specificity、accuracy and prognostication of the third minute systolic blood pressure were:55.6%、82.0%、73.9% and 57.7%.Conclusion The index of the third minute systolic blood pressure is much more significant than the traditional ST standard in the specificity、accuracy and prognostication of diagnosing coronary heart disease.
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BACKGROUND: The goal of this study is to evaluate the differences of the rate and the ratio of heart rate changes, which is well known to reflect the vagal reactivation, after peak exercise between ischemic heart disease and normal during treadmill exercise test. Additionally R-wave amplitude changes are evaluated to have the discriminal power between ischemic heart disease and normal. METHODS: We have studied 253 human (196 control, 57 patients) who took the symptom-limited exercise test using Marquette case 8000 model. The 57 patients who showed the positive result by exercise test have confirmed by coronary angiography. The rate of heart rate changes was defined as the absolute difference of the heart rate subtracted by the just-previous stage heart rate. The ratio of heart rate changes was defined as the percentile of the rate of heart rate changes comparing to the just-previous stage heart rate. The changes of R-wave amplitude at lead V5 and aVF were obtained by the subtraction of R-wave amplitude at the peak exercise stage from that at the standing rest stage respectively. Additively heart rate recovery was defined as the rate of heart rate change which was obtained at 1 minute later after peak exercise. RESULTS: In patients and control, the resting heart rate were 70 +/- 13 bpm and 69 +/- 11 bpm (p>0.05), and the peak heart rate were 136 +/- 22 bpm and 155 +/- 18 bpm respectively (p<0.001). The rate of heart rate changes in patients group were significantly lower than that in control at 1 minute, 3 minute, and 5 minute respectively (p<0.001, p=0.008, p=0.002). The ratio of heart rate changes in patients group were also significantly lower than that in control at 1 minute, 3 minute, and 5 minute respectively (p=0.017, p=0.027, p=0.002). With comparing both groups, the incidences of ventricular ectopy were not different during exercise and recovery stages, and the difference in the changes of R-wave amplitude at lead V5 and aVF were not observed respectively. CONCLUSION: The rate and ratio of heart rate changes are significantly lower in iscemic heart disease than in normal, and these are resulted from the depression of vagal reactivation. These findings are supplemental to make a diagnosis and a arrhythmic risk stratification of ischemic heart disease.
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Humans , Coronary Angiography , Depression , Diagnosis , Exercise Test , Heart Diseases , Heart Rate , Heart , Incidence , Myocardial IschemiaABSTRACT
Objective To investigate the value of treadmill exercise test and dipyridamole electrocardiography stress test (DP T) in diagnosis of coronary heart diseases (CHD), with an attemp of developing a safe, effective and simple diagnostic method for patients intolerable to the exercise. Methods Fifty two male patients aged from 41 to 75 years, averaged 58.44?8.79 years and with suspected or confirmed CHD were recruited to perform the treadmill exercise test, DP T and coronary angiography, respectively, within one month. Results The sensitivity and specificity of the treadmill exercise test for diagnosing CHD were 100% and 78.95%, respectively, while those of DP T for diagnosing CHD were 79.31% and 65.22%, respectively.As corresponded to the number of sites of coronary artery lesions,the numbers of cases with positive results revealed were 0, 2, 10 and 17 by the treadmill exercise tests and 0, 6, 11 and 15 by DP T, respectively.Based on the criteria of DP T, the sensitivity and specificity symptom, the changes in electrocardiography (ECG) and the combination of the two, for diagnosing CHD were 72.41%, 65.22%; 65.52%, 82.61%;and 79.31%, 65.22%, respectively. Conclusion The sensitivity and specificity of the treadmill exercise test and the DP T in the diagnosis of CHD were similar. More positive cases were revealed in above mentioned tests as the sites and degree of coronary artery lesion increased. DP T was particularly suitable for helping diagnose CHD in patients intolerable to exercise.
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AIM:To evaluate the diagnostic value of co-detection of ischemia modified albumin (IMA) and treadmill exercise test (TET) for silent myocardial ischemia (SMI).METHODS:80 patients [55 males and 25 females;mean age (54?8) years] with suspected SMI were selected.All patients were examined with TET and coronary arteriongraphy(CAG) in one week.IMA was detected before TET and two hours after TET.All patients were divided into CHD and NCHD groups combined with the results of CAG.Changes in the concentration of IMA were observed of two groups before and after TET.The diagnostic value of co-detection of ischemia modified albumin and treadmill exercise test was evaluated for SMI.RESULTS:Among the 80 patients,it was diagnosed as CHD 33 cases,NCHD 47 cases.There were significant higher levels of IMA after TET in CHD group (P0.05).IMA levels were significantly higher in the patients of CHD after TET than those patients of NCHD[(13.3?3.5) vs (4.7?1.8) ng/mL,P0.05).The sensitivity value was 81.8% for IMA after TET,specificity was 76.6%,positive predictive value was 71.1%,negative predictive value was 85.7%.The sensitivity was 93.8% with the co-detection of IMA and TET,specificity was 87.5%,positive predictive value was 83.3%,negative predictive value was 95.5%.CONCLUSION:IMA is a useful biochemical marker for the early myocardial ischemia.There is a high sensitivity and negative predictive value for IMA two hours after TET in the diagnosis of SMI.There is much higher diagnostic value with the co-detection of IMA and TET.
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BACKGROUND: QT dispersion (QTd) represents inhomogeneous ventricular repolarization. Increased QTd has been reported to be associated with ischemic heart disease and sudden cardiac death. Successful percutaneous coronary angioplasty (PTCA) produces a favorable recovery of inhomogenous repolarization and reduces QTd. Although treadmill exercise test is commonly used for follow-up test after PTCA, limited data are available about QTd during treadmill test. The purpose of this study was to evaluate the change in QTd and determine its clinical role in follow-up treadmill exercise test after coronary stenting. METHODS: 41 patients with significant coronary artery disease underwent successful coronary stenting, while 46 patients were medically treated. Treadmill exercise test was performed to compare QTd between two groups as a follow-up test at 6 months after coronary stenting and medical therapy. Treadmill exercise test was recorded in pre-test, peak exercise, and recovery 2 minutes phase. QTd and corrected QT dispersion (QTcd) were measured in these ECGs using a digitizer. RESULTS: Coronary stenting significantly reduced QTd and QTcd at 6 months after coronary stenting. QTd and QTcd did not show significant difference between coronary stenting and medical therapy group at initial EKG before treatment. After coronary stenting, QTd and QTcd were significantly reduced than those of medical therapy group. And the changes in QTd and QTcd were more marked at peak exercise (28.2+/-11.9 and 39.3+/-16.2 msec in coronary stenting group vs 40.4+/-20.5 and 57.8+/-30.0 msec in medical therapy group). Lesion location and diseased vessel number were not associated with changes in QTd and QTcd. CONCLUSION: Coronary stenting reduced QTd and QTcd significantly in follow-up treadmill exercise test. Coronary stenting appears to be more effective to relieve myocardial ischemia and to improve inhomogenous ventricular repolarization than medical therapy. The measurement of QTcd during treadmill exercise test may be a useful index to evaluate myocardial ischemia after coronary stenting. Clinical relevance of these finding will require further study.
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Humans , Angioplasty , Coronary Artery Disease , Death, Sudden, Cardiac , Electrocardiography , Exercise Test , Follow-Up Studies , Myocardial Ischemia , StentsABSTRACT
BACKGROUND AND OBJECTIVES: QT interval on ECG strongly depends on heart rate. Prolonged early phase of repolarization may be responsible for mechanisms of arrhythmogenesis. Investigation of physiologic behavior of QT interval and their relation to cardiac cycle length may explain mechanisms of arrhythmogenesis. The aim of this study is to investigate the physiologic behavior of the QT intervals during various stages of treadmill exercise test in healthy airlines pilots. METHOD: A retrospective analysis of treadmill exercise test ws done in 60 healthy men. Each underwent 10 ECG recordings, which were performed in resting, 1 minute, 2 minute and 3 minute of exercise stage 1, 2 and 3 of Bruce protocol respectively. The QT interval was measured as the time interval from the earliest Q onset to the peak T wave (QTp) in precordial lead V2. RESULTS: The mean heart rate before exercise was 72 +/-5 beats/minute, and at 1, 2 and 3 minute of exercise stage 1, 2 and 3 were 96 +/-8, 97 +/-7, 99 +/-9, 112 +/-9, 117 +/-9, 120 +/-10, 137 +/-12, 145 +/-12 and 152 +/-10, respectively. The d-QTp/d-RR at 1, 2 and 3 minute of exercise stage 1, 2 and 3 were 10.4 +/-5.9, 14.1 +/-5.8, 15.1 +/-6.2, 14.8 +/-4.2, 16.1 +/-3.7, 16.3 +/-3.5, 16.8 +/-2.9, 17.1 +/-3.0%, respectively. The QTp interval respond slowly for rapid changes in cycle length. The change of QTp interval showed a linear correlation with the change of the RR interval (y=0.189x-10.864, r=0.83, P<0.0001). CONCLUSION: The changes in QT interval lagged behind the rapid and sustained changes in the heart rate elicited by treadmill exercise test. It is concluded that the d-QTp/d-RR showed hysteresis in the changes in the RR interval may be useful in assessing in the dynamic regulation of the ventricular repolariza-tion process.
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Humans , Male , Electrocardiography , Exercise Test , Heart Rate , Retrospective StudiesABSTRACT
BACKGROUND: Exercise testing is an importnat diagnostic and prognostic procedure in the assessment of patients with ischemic heart disease. But standard ST-segment depression criteria was not high enough to estimate coronary srtery disease. Recently, the heart rate adjustment of ST segment depression, ST segment/heart rate slope and index, have been proposed as a more accurate criteria for diagnosing significant coronary artery disease. The objective of this study was to compare the discriminating power of proposed ST segment/heart rate slope and index with that of a standard method of assessing exercise-induced ST segment depression for estimating coronary artery disease. METHODS: Sixty nine patients with ischemic heart disease were studied with exercise treadmill testing and coronary angiography. Computer-measured ST-segment amplitudes were obtained and analysis of the heart rate-adjusted ST segment depression(ST/HR slope and big up tri, Delta ST/HR index) was done. The sensitivity, specificity, and extent of coronary artery disease on each criteria were compared. RESULTS: 1) The sensitivity of big up tri, Delta ST/HR index partition of 1.6uV/beats/min was slightly higher(83%) and the specificity of ST/HR slope partition of 2.4uV/beats/min was higher(87%) than the standard exercise electrocardiographic criteria. 2) Early onset of ischemic ST-segment depression, profound ST-segment depression(> or =2mm), and downsloping ST-segment were associated with more extensive coronary artery disease. 3) On ST/HR slope, no CAD was 1.7+/-0.26uV/beats/min, one vessel disease was 2.6+/-0.34 uV/beats/min, two vessel disease was 2.7+/-1.36uV/beats/min, one vessel disease was 2.8+/-0.35uV/beats/min, and on big up tri, Delta ST/HR index, no CAD was 1.8+/-0.38uV/beats/min, one vessel disease was 2.8+/-1.36uV/beats/min, two vessel disease 3.4+/-1.44uV/beats/min, and three vessel disease was 3.7+/-2.95uV/beats/min. The increment of ST/HR slope and big up tri, Delta ST/HR index were associated with the coronary artery disease and its severity, but the correlations were not high enough. CONCLUSION: The heart rate adjustment of ST segment depression was not high enough for improved detection of coronary artery disease, compared with standard ST-segment depression criteria. But these indexes can be improved the clinical usefulness of the treadmill exercise test for coronary aretry disease.