Diagnostic value of the ratio of recovery systolic blood pressure to peak exercise systolic blood pressure for the detection of coronary artery disease

It has been previously reported that at treadmill exercise testing an abnormal ratio of recovery systolic blood pressure (SBP) to peak exercise SBP is more sensitive than exercise-induced angina or ST segment depression for diagnosing coronary artery disease (CAD). To investigate whether the SBP ratio keeps its diagnostic value during upright bicycle exercise, we evaluated the ratio of postexercise SBP to peak SBP in 73 patients with angiographically documented CAD and in 48 patients with normal coronary arteries (OV group) undergoing maximal stress testing on a bicycle ergometer. Three minutes after exercise ended, SBP ratio was significantly higher in the CAD than in the OV group (0.79 +/- 0.1 vs 0.71 +/- 0.08; p less than .001). Setting the upper normal limits of the recovery SBP ratio at 2 SDs from the mean for the OV group (SBP ratio = 0.98 and 0.88 at 1 and 3 min after exercise, respectively), with an increase or no change in SBP ratio at between 1 and 3 min of recovery considered an abnormal response, the sensitivity of SBP ratio was 30%, the specificity was 83%, and the accuracy was 51%. The respective values for ST depression were 81% (p less than .0001 vs SBP ratio), 48% (p less than .001 vs SBP ratio), and 67% (p less than .01 vs SBP ratio). Thus, for bicycle ergometer exercise testing, ST segment depression seems to be more accurate than SBP ratio in diagnosing CAD.     

Comparison of postexercise and transesophageal atrial pacing two-dimensional echocardiography for detection of coronary artery disease

Two-dimensional (2-D) echocardiography during transesophageal atrial pacing (TAP) was recently proposed as an alternative to exercise 2-D echocardiography for the diagnosis of coronary artery disease (CAD). To compare these 2 methods, 78 consecutive patients with good-quality echocardiographic (echo) examinations at rest were studied. Two-dimensional echocardiography was performed immediately after supine bicycle exercise and at peak atrial pacing obtained with transesophageal atrial stimulation. Twenty patients were excluded: 16 because of poor quality of 2-D echo images after exercise and 4 because of inadequate TAP studies (atrial capture not achieved in 2 and intolerance in 2). Of the remaining 58 patients, 39 had significant CAD (at least 75% diameter stenosis of at least 1 major coronary artery) and 19 had no significant CAD. The 2 test responses were considered positive if a wall motion abnormality was detected during pacing or after exercise. Sensitivity and specificity were 82% and 95% after exercise and 90% and 84% during TAP. In patients with significant CAD but without wall motion abnormalities at rest, sensitivity was 75% during pacing and 56% after exercise. In patients with significant CAD, the wall motion score index decreased significantly with both types of stress; during pacing wall motion score index was significantly lower than after exercise. Thus, 2-D echo during TAP appears to be a feasible and reliable alternative to postexercise echo for the detection of CAD.     

Radionuclide assessment of left ventricular function during dobutamine infusion in patients with coronary artery disease: comparison with ergometer exercise

The effects of dobutamine on left ventricular function were assessed employing radionuclide ventriculography (RNV) in 7 normal subjects (Group 1) and 21 patients with coronary artery disease (Group 2). After routine bicycle ergometer exercise RNV, dobutamine infusion was started at 5 micrograms/kg/min and the dosage was increased by 5 micrograms/kg/min every 4 minutes to a total of 15 micrograms/kg/min. In Group 1, left ventricular ejection fraction (LVEF) increased by both ergometer exercise and dobutamine infusion. In Group 2, LVEF did not increase during exercise, but increased during dobutamine infusion without evidence of significant myocardial ischemia. Only 2 patients in Group 2 had new regional wall motion abnormality. Left ventricular end-diastolic volume (LVEDV) in Group 2 increased from 191 +/- 19 to 210 +/- 18 ml during ergometer exercise, but decreased from 193 +/- 18 to 153 +/- 19 ml during dobutamine infusion. Short-term low-dose infusion of dobutamine may be used in patients without evidence of significant myocardial ischemia, but probably cannot be substituted for exercise testing in patients with mild to moderate coronary artery disease.     

Assessment of coronary artery disease in hemodialysis patients with delayed systolic blood pressure response after exercise testing

BACKGROUND: We evaluated usefulness of the postexercise systolic blood pressure (SBP) response for detecting coronary artery disease (CAD) in hemodialysis patients. METHODS: A treadmill exercise testing was done, and the SBP response was measured in 44 hemodialysis patients (30 men, 14 women; age 41 to 81 years). The postexercise SBP response was defined as the ratio of SBP after 3 minutes of recovery to SBP at peak exercise. RESULTS: The SBP ratio of the 25 subjects with coronary artery stenosis (1.01+/- 0.13) was significantly greater (p<0.01) than 19 subjects without coronary artery stenosis (0.83+/- 0.10). An SBP ratio greater than 0.92 identified CAD with higher sensitivity, specificity, and accuracy than did the conventional ST-segment depression criterion (76 vs. 56%, 90 vs. 53%, and 82 vs. 55%, respectively). CONCLUSION: Determination of the SBP ratio is a clinically useful, noninvasive method for accurately detecting CAD in hemodialysis patients.     

Exercise two-dimensional echocardiography for diagnosis of coronary artery disease

To improve ultrasound images during exercise 2-dimensional echocardiography (2-D echo), a device was developed to hold the transducer and maintain its orientation relative to the heart. The value of this technique in detecting wall motion abnormalities and changes in ejection fraction was evaluated in 54 men undergoing stress test for angina. Thallium-201 scanning, electrocardiography and exercise 2-D echo were recorded concurrently. Technically satisfactory echo studies were obtained in 47 patients (87%). The sensitivity and specificity of exercise echo in the detection of myocardial ischemia as judged by wall motion abnormalities were 100% and 93%, respectively. Sixteen patients with normal thallium scans increased their ejection fraction (EF) estimated by echo (from 52 +/- 1% at rest to 67 +/- 1% at maximal exercise, p less than 0.001); all showed an increase of 5% or more. In contrast, 11 patients who had reversible thallium scan defects showed a consistent decrease in EF (from 53 +/- 2% at rest to 43 +/- 2% during exercise, p less than 0.001); 20 patients with irreversible thallium scan defects showed no specific trend in the EF (48 +/- 2% at rest and 50 +/- 2% during exercise, difference not significant). Changes in heart rate and blood pressure did not distinguish the 3 groups of patients. Our technique of exercise 2-D echo may be useful for detecting wall motion abnormalities and EF changes during exercise and possibly enhance the sensitivity of thallium scanning in the noninvasive diagnosis of coronary artery disease.     

Comparison between regional myocardial blood flow measurements and results of exercise tests

The relationship between regional myocardial blood flow and the results of exercise tests were evaluated in 54 patients, 40 of whom had angiographically demonstrated coronary artery disease (CAD) and 14 had normal angiograms. After 20 patients had 2-step tests, 20 had bicycle ergometry, and 14 had treadmill tests, regional myocardial specific blood flow (RMBF) at rest was determined by selective injections of xenon-133 into the left coronary artery and quadrantic washout measured with an Anger camera. RMBF (ml/min/100 gm, mean +/- SE) was significantly lower in patients with coronary artery disease (72 +/- 3) than in normals (91 +/- 7, p less than .05) but RMBF in 12 CAD patients with negative exercise tests (75 +/- 6) was similar to regional myocardial blood flow in 28 coronary artery disease patients with positive exercise tests (71 +/- 4). Degree of ST depression did not influence results. Although measurement of RMBF and exercise testing are both useful procedures in the evaluation of patients with CAD, the data in the present study indicate the RMBF measurements at rest cannot predict the result of the postexercise ECG and vice versa.     

Effect of exercise mode on oxygen uptake and blood gases in COPD patients

Patients with chronic obstructive pulmonary disease (COPD) are characterised by decreased exercise tolerance, and, more variably, exercise induced hypoxaemia (EIH). Evaluation of physical work capacity and physiological responses to exercise may be performed by various procedures, but there are diverging opinions as to which exercise test should be preferred. In the current study, oxygen uptake and arterial blood gases in COPD patients have been compared during submaximal and maximal exercise on treadmill and ergometer bicycle. Treadmill exercise resulted in higher peak oxygen uptake than bicycle exercise (1111+/-235 vs. 987+/-167 ml min(-1), P<0.02), while the plasma lactate levels were higher during cycling (1.8+/-0.8 vs. 3.8+/-1.7 mmol l(-1), P<0.001). Neither carbon dioxide output, ventilation, nor rate of perceived exertion (Borg RPE scale) showed significant differences between the two modes of exercise. The EIH during both maximal (delta Sa,O2 = -5.6+/-4.2 vs. -3.4+/-5.1%) and sub-maximal exercise was more pronounced during treadmill walking than during cycling. The present study indicates that the VO2peak in COPD patients is higher, the maximal lactate concentrations lower and the development of EIH more pronounced when exercise testing is performed on a treadmill than on a bicycle ergometer.     

Reproducibility of equilibrium radionuclide ventriculography in patients with coronary artery disease: Response of left ventricular ejection fraction and regional wall motion to supine bicycle exercise

To evaluate the reproducibility of ejection fraction (EF) and regional wall motion (RWM) analyses by rest and exercise equilibrium radionuclide ventriculography (RNV) in the presence of coronary artery disease (CAD), 18 patients underwent two maximum, multistage supine bicycle exercise studies separated by an interval of 2 weeks. There were no significant differences in EF between the two studies, both at rest (56.0 ± 13.8% vs 58.2 ± 11.7%, p = NS) and with exercise (51.1 ± 17.6% vs 54.3 ± 17.6%, p = NS) and a highly significant correlation was shown between the two groups of values (rest r = 0.90, exercise r = 0.93, p < 0.001). There was no significant difference in the change from rest to exercise (?4.9 ± 12.0% vs ?3.8 ± 11.5%, p = NS) between the two studies and the correlation was highly significant (r = 0.69, p < 0.01). The interstudy variabilities were 2.2 ± 6.1% and 1.2 ± 7.3% for rest and exercise, respectively, and 2.0 ± 9.2% for the change from rest to exercise. Ninety-four percent of both rest and exercise regions had similar RWM. Eighty-one percent of the abnormally contracting regions were common to both exercise studies. Utilizing conventional criteria for the diagnosis of CAD, 11 patients had abnormal EF response and nine had abnormal RWM response to exercise on both studies. Combining EF and RWM criteria resulted in the diagnosis of CAD in 15 patients in both studies. We conclude that: (1) there were no significant differences in rest and exercise radionuclide EF and RWM between two supine bicycle exercise studies performed 2 weeks apart in patients with stable CAD and there were significant correlations between the two studies; (2) despite these correlations, the interstudy variabilities emphasize the need for the inclusion of reproducibility studies in all evaluations of interventions by exercise radionuclide ventriculography; and (3) the variations in EF and RWM response to exercise result in a lack of uniformity between the two studies regarding the diagnosis of CAD based on conventional RNV criteria.     

Verification of the left ventricular ejection fraction from gated myocardial perfusion studies (GSPECT)

INTRODUCTION: The perfusion study (which may be obtained using SPECT or GSPECT technology within six hours of administration of the radionuclide Tc-99m-MIBI) reflects the regional blood supply to the left ventricular [LV] myocardium at the time of radionuclide administration (i.e. at rest, at peak exercise, or at peak vasodilatation), while the values of EF, EDV, and ESV measured using GSPECT are parameters of LV contractility at the time of image acquisition (i.e. at rest or in a nearresting state following exercise or vasodilatation). Planar radionuclide ventriculography [RNV] is, however, considered to be the most accurate method for calculating LVEF. AIMS: The main goal of the study was to compare the values of EF obtained by the most frequently used method, GSPECTQGS, and the reference method, RNV - taking into consideration various clinical scenarios (presence or absence of LV dilatation) and various conditions under which GSPECT was recorded (at rest, post-exercise, or post-dipyridamole). METHODS: Two hundred patients (145 males) aged 58+/-11 (18-80) with previously confirmed (n=166, of whom 108 had a history of myocardial infarction) or suspected (n=34) coronary artery disease were included in the study. Ranges of normal values for EF, EDV, and ESV were established based on a group of 26 'normal' subjects. LV dilatation was defined as an EDV >127 ml (at rest, measured by QGS) - this was present in 88 patients. Myocardial perfusion studies were obtained using GSPECT following administration of Tc-99m-MIBI at rest (all patients), as well as one hour after treadmill exercise (138 patients) or dipyridamole administration (48 patients). The resting RNV was conducted within three weeks of the GSPECT exam. The EF values obtained by QGS and RNV were compared for patients with and without LV dilatation. EF, EDV, and ESV values obtained by QGS were compared for resting patients, post-exercise, and post-dipyridamole. RESULTS: 1. The GSPECT EF values calculated using QGS software, at rest or one hour after treadmill exercise or dipyridamole administration, demonstrated, for the study population as a whole, a significant, strong correlation with the results obtained by the reference method, RNV (correlation coefficient, r> or =0.86). The correlation was stronger in patients with LV dilatation than in those without. Both in patients with and without LV dilatation the correlation of EF with RNV was slightly weaker for postexercise (relative to resting) and post-dipyridamole (relative to post-exercise) measurements. 2. QGS tended to underestimate the absolute values of EF, as compared to RNV. 3. In post-exercise and post-dipyridamole measurements, relative to the resting measurements (in patients with previously diagnosed or suspected coronary artery disease) the mean values of EF were lower while EDV and ESV were higher. CONCLUSIONS: In order to complement data on myocardial perfusion, the GSPECT-QGS technique should be optimally used to calculate LV contractility parameters at rest (as opposed to post-exercise or post-dipyridamole), and include a range of normal values for EF, EDV, and ESV, obtained using QGS. Of note, EF measurements by GSPECT are more accurate for dilated than non-dilated ventricles.     

N-terminal pro-brain natriuretic peptide predicts myocardial ischemia and is related to postischemic left-ventricular dysfunction in patients with stable coronary artery disease.

BACKGROUND: The N-terminal-pro-B natriuretic peptide (Nt-pro-BNP) is of diagnostic and prognostic value in coronary artery disease (CAD). We assessed the relationship between Nt-pro-BNP and (1) the extent of ischemia on stress myocardial perfusion imaging (MPI), and (2) changes between the basal and postexercise ejection fraction (EF), in stable patients with a normal EF. METHODS AND RESULTS: One hundred and two patients with stable, documented CAD (EF, 62% +/- 8%) underwent an exercise-rest thallium-201 gated-MPI and serial Nt-pro-BNP assays. Myocardial perfusion imaging produced abnormal results in 57 patients (56%; group 1), and normal results in 45 patients (44%; group 2). Median baseline, immediate postexercise, and 3-hour postexercise Nt-pro-BNP values were higher in group 1 than in group 2: 182 vs 85, 201 vs 86, and 212 vs 99 pg/mL, respectively (P < .001 for all). Postexercise EF decreased in group 1 (53% +/- 11% vs 62% +/- 10%, P < .001), but not in group 2 (61% +/- 9% vs 62% +/- 7%, NS). The Nt-pro-BNP ruled out significant ischemia with a negative predictive value of 0.90, whereas patients within the higher tertile of Nt-pro-BNP had a fivefold higher risk of ischemia compared with patients within the lower tertile. CONCLUSIONS: The post-stress increase in Nt-pro-BNP is related to myocardial ischemia and to postischemic left-ventricular dysfunction, and accurately predicts the presence or absence of myocardial perfusion defects.     

运动试验收缩压和舒张压反应异常对冠心病的诊断价值及其机制

104例患者接受冠脉造影和平板运动试验,评价运动后SBP恢复比和运动中DBP增量对冠心病的诊断价值。SBP恢复比与DBP增量异常的敏感度与特异度分别为59%、52%与96%、92%,而ST段压低标准则分别为71%与84%。高血压病组中三种指标的假阳性率分别为38%、42%与33%。SBP恢复比与EF呈负相关,与SVR呈正相关,提示运动引起的血压反应异常是左心功能受损和SVR增加所致。     

Usefulness of the postexercise response of systolic blood pressure in the diagnosis of coronary artery disease

The normal decline in systolic blood pressure (SBP) during the recovery phase of treadmill exercise does not occur in some patients with coronary artery disease (CAD). In others the recovery values of SBP exceed the peak exercise values. To examine the diagnostic value of this observation, we studied 31 normal subjects and 56 patients undergoing treadmill exercise before coronary cineangiography. Because of large differences in peak exercise pressures between the two groups, recovery ratios were derived by dividing the SBP at 1, 2, and 3 min after exercise by the peak exercise SBP. The 1, 2, and 3 min ratios in the normal subjects declined steadily from 0.85 +/- 0.07 (SD) to 0.79 +/- 0.06 and to 0.73 +/- 0.06, respectively, while the ratios in the patients with CAD remained elevated at 0.97 +/- 0.12 to 0.97 +/- 0.11 to 0.93 +/- 0.13. With use of the upper limits defined by two SDs of the normal value, recovery ratios were compared with the occurrence of angina and with ST segment depression on the exercise electrocardiogram in the patients with CAD. Abnormal ratios were more frequent in patients with CAD (53/56, 95%) than in those with ST segment depression (33/56, 59%), angina (37/56, 66%), and either ST segment depression or angina (42/56, 75%). Twenty of the patients with CAD who were on no medication underwent an additional treadmill exercise test on a separate day and no significant differences were found in the ratios from the two tests. Ten additional patients with CAD underwent treadmill exercise testing while on placebo and while on a beta-blocker.(ABSTRACT TRUNCATED AT 250 WORDS)     

R-wave amplitude changes during exercise stress testing: patients with dilative cardiomyopathy compared to patients with coronary artery disease

R-wave amplitude (RWA) depends to a large extent on the left ventricular filling volume. Changes of RWA are attributed to the Brody-effect. Exercise has been shown to induce a decrease of RWA in a healthy population and an increase in patients with coronary artery disease (CAD). No clear data exist for cardiomyopathy (CMP). Controls (n = 12), patients with CMP (n = 32) and CAD (n = 58) were compared. Alterations of RWA (Wilson lead V5) were correlated with parameters of a bicycle exercise test including resting and exercise hemodynamics and parameters of LV-function including EF, LVEDV and LVEDP. CMP compared to CAD had smaller RWA at rest (0.78 +/- 0.47 vs 1.32 +/- 0.72 mV, P less than 0.01). During comparable levels of exercise CMP (EF 35 +/- 14%) showed no significant changes of RWA. CAD (EF 57 +/- 16%) presented an increase of RWA by +0.11 +/- 0.23 mV (P less than 0.01), while controls showed a straight decline of RWA (-0.31 +/- 0.24 mV). In patients with CAD delta RWA (RWA max exercise - RWA rest) was a more sensitive parameter for detection of disease (assuming delta RWA greater than or equal to +0.1 mV, 36/58 patients) than maximal ST-segment changes (ST-segment-depression in lead V5 greater than or equal to 0.2 mV at 0.08 sec after J-point, 22/58 patients). Precordial leads V2, V4, V5 and V6 showed similar changes. This paper supports the theory that changes of wall thickness or changes in the amount of air respective to the amount of fluid in the lungs are responsible for RWA changes. These changes are clearly dependent on the severity of the disease and on left ventricular function. Therefore measurement of RWA changes during exercise may offer additional information in patients with CAD as well as in patients with CMP.     

Comparative value of 2-dimensional echocardiography and radionuclide angiography for quantitating changes in left ventricular performance during exercise limited by angina pectoris

To compare left ventricular (LV) ejection fraction (EF) measurements made during exercise by 2-dimensional echocardiography (2-D echo) and gated equilibrium radionuclide angiography (RNA), 18 patients with angina pectoris were studied during graded upright bicycle ergometry. For RNA, the left anterior oblique view was used with the patient grasping the camera gantry during the 2-minute count acquisition required for EF calculation. For 2-D echo, biapical views were recorded with the patient's arms resting on a platform, and EF was calculated from volume measurements made using Simpson's rule. Exercise duration was similar for both studies, but EF at maximal exertion was higher by RNA than by 2-D echo (46 ± 15 % vs 35 ± 15 %, p < 0.001). However, echo EF determined 1 minute before maximal exertion, which corresponded to the midpoint of the 2-minute count collection period for RNA, was similar to the RNA value at maximal exercise (44 ± 12 %). Analysis of individual EF values by 2-D echo at rest, at 1 minute before maximal exercise and at maximum exercise showed that there was little change in EF during submaximal exercise, but that EF decreased considerably at maximal exertion when the patients had angina pectoris. Therefore, when the time frame of data acquisition is considered, exercise 2-D echo and gated equilibrium RNA provide similar information regarding LVEF. The latter has the advantage of a 100 % successful study frequency and the former is superior in its ability to detect the rapid changes in LV performance during exercise-limiting symptoms.     

Diagnostic accuracy of 2-D echocardiography for detection of exercise-induced wall motion abnormalities in patients with coronary artery disease: comparison to biplane cineventriculography

To determine the accuracy of two-dimensional echocardiography (2-D echo) for assessment of exercise-induced wall motion abnormalities in patients with coronary artery disease, the results of stress echocardiography were compared with exercise cineventriculography. In 56 consecutive patients, biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echo was obtained using the apical two- and four-chamber-views for left ventricular imaging under identical conditions. In 6 of the 56 patients 2-D echo, in 8 patients cineventriculogram, and in 2 patients both methods were of inadequate quality at rest or during exercise. Of the remaining 40 patients, 34 had coronary artery disease. Local wall motion in 360 wall segments from these patients was analyzed. In 49 segments (14%) in 24 of these patients exercise-induced ischemic wall motion abnormalities were evident during cineventriculography. Only 24 of these 49 asynergies (49%) were also recognized by 2-D echo. Using cross-sectional echocardiography, ischemia-related wall motion abnormalities were best detected septal, whereas apical asynergies were identified in only 3 of 12 segments (25%). Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected of having coronary artery disease is limited and restricted to patients where excellent visualization of the left ventricular endocardium is possible.     

Comparative diagnostic value of exercise polarcardiography and 14-lead electrocardiography in the detection of coronary artery disease

Early postexercise polarcardiographic (PCG) changes in the ST segment vector, as reflected in the variable MS X theta, are reported to clearly distinguish normal subjects from those with myocardial ischemia. We prospectively assessed the value of this test in detecting coronary artery disease (CAD) during treadmill exercise in 178 patients within 1 week of diagnostic coronary angiography. The average postexercise MS X theta was 16.9 +/- 9.7 mV degrees in patients with CAD, whereas it was 16.2 +/- 10.2 mV degrees in patients with CAD (p = NS). The optimal ratio of sensitivity to specificity, using different normal-abnormal cutoff values, was 57% and 56%, respectively, for a delineating MS X theta value of 12. The sensitivity and specificity of a simultaneously recorded 14-lead ECG using the criterion of exercise-induced horizontal downsloping ST segment depression greater than or equal to 0.1 mV, was 71% and 78%, respectively. The PCG results were not improved by analyzing MS X theta during exercise, or by analyzing the difference in MS X theta between rest and exercise or rest and postexercise. The sensitivity of the PCG for multivessel or left anterior descending CAD was higher than for less severe forms of CAD, but was significantly less sensitive than the 14-lead exercise ECG (70% versus 84%; p = 0.02; and 62% versus 75%; p = 0.05, respectively). Thus, exercise polarcardiography, as employed in the present study, does not improve the diagnostic content of the 14-lead exercise ECG. Contrary to previous reports, there is no clear separation of normal from abnormal MS X theta values when a prospective series of patients is tested.     

Myocardial ischemia with negative stress electrocardiography: evaluation by stress RI studies

Patients with negative stress electrocardiography (ECG) (no ST segment depression) were re-evaluated by means of stress RI studies including 201T1 single photon emission computed tomography (SPECT) and 99mTc-RBCs radionuclide ventriculography (RNV). Four hundred seven patients, including 303 with old myocardial infarction (OMI; SPECT: 188, RNV: 115) and 104 with effort angina (EA; SPECT: 58, RNV: 46), all of whom underwent left ventriculography and coronary arteriography, were re-evaluated by symptom-limited graded bicycle ergometer exercise RI testing. The results were as follows: 1. Among those with negative stress ECG (53% of OMI and 31% of EA), 54% and 73% of OMI and EA, respectively, had positive SPECT. 2. Among those with negative stress ECG (56% of OMI and 39% of EA), 70% and 39% of OMI and EA, respectively, had positive delta EF (poor increase in ejection fraction: delta EF less than 5%) and, 41% and 28% of OMI and EA had deteriorated regional wall motion. 3. Those with OMI and negative ECG showed no correlations with the numbers of diseased vessels, infarcted sites, or ischemic areas. In conclusion, RI testing appears to be a significantly more sensitive means of detecting stress-induced ischemia, compared to stress ECG.     

Comparison of five different stress testing methods in the ECG diagnosis of coronary artery disease. Correlation with coronary arteriography.

Five different stress testing methods: bicycle ergometer exercise (BE), treadmill exercise (TD), isoproterenol infusion test (IPN), dopamine infusion test (DPM), and atrial pacing (AP), were performed on 90 male patients who underwent coronary arteriography. Ischemic S-T segment depression of 1.0 mm or greater was used as the criterion for a positive test. Within the group of 56 subjects having significant coronary artery disease (CAD) the diagnostic sensitivity of the single tests was as follows: 64.3% for BE, 66.1% for TD, 69.6% for IPN, 41.1% for DPM, 75.0% for AP. For the 34 subjects with no CAD the folowing specificity was found: 88.2% for BE and for TD, 82.3% for IPN, 85.3% for DPM, 63.8% for AP. When the results of the different tests were combined, it was seen that the association of an ergometric test with IPN enhanced the sensitivity of the exercise test (p less than 0.05) without significantly decreasing the specificity.     

Acute impairment of the endothelial function by maximal treadmill exercise in patients with intermittent claudication, and its improvement after supervised physical training.

AIM: The aim of this study was to determine the effects of maximal exercise and of physical training on endothelial function (EF) of patients with intermittent claudication (IC). METHODS: EF, assessed by ultrasonography of the brachial artery, has been measured in 22 male patients with IC before (pre-exercise EF) and after (postexercise EF) maximal treadmill test. Absolute claudication distance (ACD) and ankle brachial index (ABI) have been measured too. The measurements have been repeated after 18 days (3 times weekly, for 6 weeks) of supervised physical training. RESULTS: Before training, the pre-exercise EF was 7.6+/-2.94 and postexercise EF 5.28+/-3.3 (-33.2%) (P<0.01). After training, the pre-exercise EF was 10.3+/-4.04, whilst postexercise EF was 7.79+/-2.56 (-18.97%) (P<0.01). The differences between the pre-exercise value before and after training and between the postexercise value before and after training were significant (P<0.01). ACD and ABI after training increased respectively from 93.95 to 166.55 m and from 0.67 to 0.71 (P<0.001). CONCLUSIONS: Endothelial dysfunction takes a relevant part in the pathophysiology of IC, with 2/3 of the patients showing an EF lower than the pathological cut-off. Maximal exercise worsens the EF, according to the trend associated with the acute inflammatory response. All these features suggest that physical activity in IC should not utilize the maximal working load, in order to avoid the high inflammatory activation and the acute complications of atherosclerotic plaque. The supervised physical training, besides confirming itself as the most effective means to increase the walking ability, also proved to be able to improve the EF of these patients, as described about other diseases. It is probable that moderate hemodynamic stress reduces the levels of the inflammatory markers and increases the flow-mediated vasodilation through an ischemic preconditioning. The increased walking ability, associated with the improvement of EF could improve the heavy systemic outcome of claudicant patients, as it has been demonstrated in patients with coronary heart disease. Further prospective survival studies on cardiovascular outcomes of trained claudicant patients are needed.     

Diagnostic usefulness of postexercise systolic blood pressure response for detection of coronary artery disease in patients with echocardiographic left ventricular hypertrophy

BACKGROUND: Although exercise-induced electrocardiographic ST segment changes are used to detect coronary artery disease (CAD), their diagnostic value is markedly decreased in patients with left ventricular (LV) hypertrophy. There have been no reports concerning postexercise systolic blood pressure (SBP) response in patients with ultrasound echocardiographic (UCG) LV hypertrophy and CAD. METHODS: Sixty-six patients with both UCG-LV hypertrophy (LV mass index 134 g/m2 or greater for men or 110 g/m2 or greater for women) and positive ST depression of at least 0.1 mV during treadmill exercise testing were studied. Coronary cineangiograms showed normal coronary arteries in 19 patients (group 1) and significant CAD in 47 patients (group 2). The SBP ratio was calculated by dividing the SBP 3 min after exercise (3 min SBP) by the SBP at peak exercise (peak SBP). RESULTS: There were no significant differences between the two groups in LV mass index, SBP at rest, exercise duration, ST depression (at rest and exercise-induced) or 3 min SBP. However, the SBP ratio was significantly higher in group 2 compared with group 1 (0.87+/-0.11 versus 1.01+/-0.18; P=0.004). Analysis of relative cumulative frequency distributions revealed an SBP ratio of 0.92 as the cutoff point for distinguishing a UCG-LV hypertrophy patient with CAD from one without CAD. The sensitivity, specificity and accuracy with an SBP ratio of 0.92 and an ST segment depression of at least 0.1 mV on treadmill exercise testing for detecting CAD in patients with UCG-LV hypertrophy were 77%, 74% and 76%, respectively. CONCLUSION: These findings suggest that the ratio of early post-exercise SBP to peak exercise SBP may be diagnostically useful in detecting CAD in patients with positive ST depression during an exercise test and UCG-LV hypertrophy.