Search

Aims: There is a paucity of randomized diagnostic studies in women with suspected coronary artery disease (CAD). This study sought to assess the relative value of exercise stress echocardiography (ESE) compared with exercise electrocardiography (Ex-ECG) in women with CAD. Methods and results: Accordingly, 416 women with no prior CAD and intermediate probability of CAD (mean pre-test probability 41%), were randomized to undergo either Ex-ECG or ESE. The primary endpoints were the positive predictive value (PPV) for the detection of significant CAD and downstream resource utilization. The PPV of ESE and Ex-ECG were 33% and 30% (P = 0.87), respectively for the detection of CAD. There were similar clinic visits (36 vs. 29, P = 0.44) and emergency visits with chest pain (28 vs. 25, P = 0.55) in the Ex-ECG and ESE arms, respectively. At 2.9 years, cardiac events were 6 Ex-ECG vs. 3 ESE, P = 0.31. Although initial diagnosis costs were higher for ESE, more women underwent further CAD testing in the Ex-ECG arm compared to the ESE arm (37 vs. 17, P = 0.003). Overall, there was higher downstream resource utilization (hospital attendances and investigations) in the Ex-ECG arm (P = 0.002). Using National Health Service tariffs 2020/21 (British pounds) the cumulative diagnostic costs were 7.4% lower for Ex-ECG compared with ESE, but this finding is sensitive to the cost differential between ESE and Ex-ECG. Conclusion: In intermediate-risk women who are able to exercise, Ex-ECG had similar efficacy to an ESE strategy, with higher resource utilization whilst providing cost savings. Central illustration Randomized controlled trial comparing diagnostic accuracy, efficacy, resource utilization, and costs based on an initial exercise echocardiography strategy vs. an exercise electrocardiography strategy in women with suspected angina. [ABSTRACT FROM AUTHOR]

Background: Exercise electrocardiography (ECG) is a noninvasive test aiming at producing ischemic changes. However, resting ECG cannot be adopted in diagnosing myocardial ischemia till ST-segment depressions. Therefore, this study aimed to detect myocardial energy defects in resting ECG using the Hilbert–Huang transformation (HHT) in patients with angina pectoris. Methods: Electrocardiographic recordings of positive exercise ECG by performing coronary imaging test (n = 26) and negative exercise ECG (n = 47) were collected. Based on the coronary stenoses severity, patients were divided into three categories: normal, < 50%, and ≥ 50%. During the resting phase of the exercise ECG, all 10-s ECG signals are decomposed by HHT. The RT intensity index, composed of the power spectral density of the P, QRS, and T components, is used to estimate the myocardial energy defect. Results: After analyzing the resting ECG using HHT, the RT intensity index was significantly higher in patients with positive exercise ECG (27.96%) than in those with negative exercise ECG (22.30%) (p < 0.001). In patients with positive exercise ECG, the RT intensity index was gradually increasing with the severity of coronary stenoses: 25.25% (normal, n = 4), 27.14% (stenoses < 50%, n = 14), and 30.75% (stenoses ≥ 50%, n = 8). The RT intensity index of different coronary stenoses was significantly higher in patients with negative exercise ECG, except for the normal coronary imaging test. Conclusions: Patients with coronary stenoses had a higher RT index at the resting stage of exercise ECG. Resting ECG analyzed using HHT could be a method for the early detection of myocardial ischemia. [ABSTRACT FROM AUTHOR]

Exercise electrocardiography (EET) is a safe and cost-effective method to predict the presence, prognosis, and severity of coronary artery disease (CAD). Various score models have been developed to increase predictive power of EET. In this study, we aimed to evaluate whether adding ST depression duration could have an effect on increasing the value of Duke treadmill score (DTS) in predicting obstructive CAD. In this single centred, cross-sectional study, we evaluated a total of 258 patients who presented with a complaint of chest pain and undergone coronary angiogram in result of a positive EET. DTS was calculated for all the patients. The new score-revised DTS- was calculated by adding total ST depression time to classical DS parameters. We compared area under the curve (AUC) of DTS and revised DTS by Delongi method. Mean age of the group was 58.43 ± 9.37, and 37.2% (n = 96) were female. Mean total ST-depression duration was 171.72 ± 91.43 msec in normal artery group,241.54 ± 118.11 msec in non-obstructive CAD group, and 281.26 ± 113.64 in obstructive CAD group.ST-depression duration in both exercise and recovery, and total ST depression duration were significantly higher in obstructive CAD group than non-obstructive and normal artery groups (p = 0.024, p = 0.01, p < 0.01, and p < 0.01, respectively). Revised DTS had significantly higher predictive value of obstructive CAD compared to classical DS (AUC (95%CI): 0.744 vs. 0.626, p < 0.001). The AUC of DS was significantly lower than the new score (z-score:3.274, p = 0.011). In conclusion, adding ST depression duration to DTS calculation is increasing the discriminative value of DTS to predict obstructive CAD. Benefits of EET within the context of the management of CAD is well-known, hence, it is clear that physicians may use revised DTS. [ABSTRACT FROM AUTHOR]

Myocardial ischemia (MI) has the highest mortality rate in the world. Traditional noninvasive MI examinations include exercise electrocardiography tests (EETs) and stress echocardiography (SE). Treadmill and dobutamine tests are commonly used as stress protocols. In the present study, 278 patients with suspected MI were examined, 66 of whom were diagnosed with MI and 212 did not show evidence of MI by coronary angiography (CAG)/coronary CT angiography (CCTA). All patients underwent clinical EET and SE evaluations prior to CAG/CCTA. All groups were compared based on specific clinical parameters including age, sex, blood pressure, heart rate, blood oxygen saturation, underlying conditions and ejection fraction/fraction shortening. The data indicated superior diagnostic efficiency of the combined EET+SE method for the diagnosis of suspected MI compared with either EET or SE alone. The sensitivity/specificity/positive predictive value and negative predictive value for detecting MI were excellent compared with those of traditional examinations. The diagnostic efficiency of the combination analysis may reduce the prevalence of MI and medical costs. The present study provided novel insight for the development of methods that may be used for MI detection and prediction. [ABSTRACT FROM AUTHOR]

Introduction: Exercise electrocardiography (EET) is frequently used in coronary artery disease, but the specificity of this test is very low. In the literature, parameters such as QT prolongation and QT dispersion which show coronary artery disease and arrhythmia were not sufficiently investigated using EET. The aim of this study was to investigate whether QT interval prolongation or dispersion (QT disp) in a positive EET test could predict critical coronary artery disease (CAD). Material and methods: Patients with a positive exercise test were included in the study. Data regarding QT, QTc (corrected QT interval) and QT disp values before, during and after EET were noted. Critical coronary artery occlusions (= 70%) was recorded from coronary angiographic images. Patients were divided into two groups (critical CAD and non-critical CAD). Results: A total of 192 patients were found to be eligible for the study. There were 126 patients in the non-critical CAD group (group 1) and 66 patients in the critical CAD group (group 2). Recovery QTc, peak QT disp, and recovery QT disp were significantly increased in group 2 (p < 0.001 for each). Also, target heart rate (p = 0.012), basal systolic blood pressure (p = 0.005) and diastolic blood pressure (p < 0.001) were significantly higher in group 1. Recovery QTc (OR = 1.051) and recovery QT disp (OR = 1.117) were determined as the independent predictors for critical CAD. The ROC analysis results indicated that critical CAD could be diagnosed with 90% sensitivity when the recovery QTc cut-off value was set as 404 ms. Conclusions: In patients with positive EET, prolonged QTc and QT disp values measured during the recovery period would predict critical CAD. Thus, the clinical accuracy of EET may be enhanced. [ABSTRACT FROM AUTHOR]

Aims Exercise electrocardiography (ExECG) is widely used in suspected stable angina (SA) as the initial test for the evaluation of coronary artery disease (CAD). We hypothesized that exercise stress echo (ESE) would be efficacious with cost advantage over ExECG when utilized as the initial test. Methods and results Consecutive patients with suspected SA, without known CAD were randomized into ExECG or ESE. Patients with positive tests were offered coronary angiography (CA) and with inconclusive tests were referred for further investigations. All patients were followed-up for cardiac events (death, myocardial infarction, and unplanned revascularization). Cost to diagnosis of CAD was calculated by adding the cost of all investigations, up to and including CA. In the 194 and 191 patients in the ExECG vs. ESE groups, respectively, pre-test probability of CAD was similar (34 ± 23 vs. 35 ± 25%, P = 0.6). Results of ExECG were: 108 (55.7%) negative, 14 (7.2%) positive, 72 (37.1%) inconclusive and of ESE were 181 (94.8%) negative, 9 (4.7%) positive, 1 (0.5%) inconclusive, respectively. Patients with obstructive CAD following positive ESE vs. Ex ECG were 9/9 vs. 9/14, respectively (P = 0.04). Cost to diagnosis of CAD was £266 for ESE vs. £327 for ExECG (P = 0.005). Over a mean follow-up period of 21 ± 5 months, event rates were similar between the two groups. Conclusion In this first randomized study, ESE was more efficacious and demonstrated superior cost-saving, compared with ExECG when used as the initial investigation for the evaluation of CAD in patients with new-onset suspected SA without known CAD. [ABSTRACT FROM AUTHOR]

The goals of this study were to determine the prevalence and determinants of false-positive exercise tests in athletes. Data from all athletes who visited the Department of Sport Medicine for assessment of sports eligibility during a 1.5-year period were reviewed retrospectively. Potential determinants of (false) positive test results that were evaluated included demographics, cardiovascular risk factors, sports characteristics, resting electrocardiogram ( ECG) abnormalities, and exercise capacity. Data from 1298 athletes were included. In 53 athletes (4.1%), the exercise ECG was classified as positive. Among 38 athletes who were referred to a sports cardiologist for further diagnostic evaluation, 36 (95%) were classified as having a false-positive test result and 2 athletes (5%) required coronary revascularization. Athletes with a false-positive test were older than athletes with a negative test (53 ± 8 vs 45 ± 13 years, P = 0.03). In conclusion, exercise electrocardiography has a low positive predictive value in asymptomatic recreational and competitive athletes, with a false-positive test result being associated with higher age. Given the relatively high prevalence of false-positive test results in this population, efforts should be made to develop strategies aimed at identifying false-positive test results in a simple noninvasive manner. [ABSTRACT FROM AUTHOR]

BACKGROUND: To explore the prognostic performance of coronary computed tomography angiography (CCTA) and exercise electrocardiography (XECG) in asymptomatic subjects. METHODS: We retrospectively enrolled 812 (59 ± 9 years, 60.8% male) asymptomatic subjects who underwent CCTA and XECG concurrently from 2003 through 2009- Subjects were followed-up for major adverse cardiac events (MACE) including cardiac death, nonfatal myocardial infarction, unstable angina, and revascularization after 90 days from index CCTA. RESULTS: The prevalence of occult coronary artery disease (CAD) detected by CCTA was 17.5% and 120 subjects (14.8%) had positive XECG. During a mean follow-up of 37 ± 16 months, nine subjects experienced MACE. In multivariable Cox-regression analysis, only the presence of CAD by CCTA independently predicted future MACE (p = 0.002). Moreover, CAD by CCTA improved the predictive value when added to a clinical risk factor model using the likelihood ratio test (p < 0.001). Notably, the prognostic value of CCTA persisted in the moderate-to-high-risk group as classified by the Duke treadmill score (p = 0.040), but not in the low-risk group (p = 0.991). CONCLUSION: CCTA provides incremental prognostic benefit over and above XECG in an asymptomatic population, especially for those in a moderate-to-high-risk group as classified by the Duke treadmill score. Risk stratification using XECG may prove valuable for identifying asymptomatic subjects who can benefit from CCTA. [ABSTRACT FROM AUTHOR]

Background A recent pilot study suggested that exercise-induced myocardial ischaemia may lead to a delayed release of cardiac biomarkers, so that later sampling, for example, at 4 h after exercise could be used for diagnostic purpose. Materials and methods In an observational study, we enrolled 129 consecutive patients referred for evaluation of a suspected coronary artery disease by rest/stress myocardial perfusion single-photon emission computed tomography. The treating cardiologist used all available clinical information to quantify clinical judgment regarding the presence of myocardial ischaemia using a visual analogue scale twice: prior and after stress testing. BNP levels were determined in a blinded fashion at rest, at peak stress and 4 h after peak stress. The presence of myocardial ischaemia was adjudicated based on perfusion single-photon emission computed tomography and coronary angiography findings by an independent cardiologist. Results Myocardial ischaemia was detected in 58 patients (45%). Patients with myocardial ischaemia had significantly higher BNP levels at all times, compared to patients without ischaemia: BNP rest (99 vs. 61 pg/mL P = 0·007), BNP stress (125 vs. 77 pg/mL P = 0·02) and BNP 4 h (114 vs. 71 pg/mL P = 0·018). Diagnostic accuracy as quantified by the area under the receiver operating characteristics curve ( AUC) was moderate for all time points ( AUC 0·64-0·66). The change in BNP between rest and 4 h did not provide added value, neither to the baseline BNP level nor to clinical judgment. Conclusion In contrast to our hypothesis, myocardial ischaemia did not lead to a differential delayed release of BNP. Late sampling did not seem clinically useful. [ABSTRACT FROM AUTHOR]

The article focuses on a research study conducted to review the outcomes of conventional exercise electrocardiography (XECG), single-photon emission computed tomography (SPECT) and coronary computed tomography angiography (coronary CTA) in patients suffering with stable coronary artery disease (CAD). It concluded that up-front diagnostic performance of coronary (CTA) was better than XECG and SPECT.

Aims Recent data have shown that exercise electrocardiogram (ECG) has no incremental prognostic value over clinical and rest ECG parameters in chest pain patients without a history of coronary artery disease (CAD). The incremental prognostic value of stress echocardiography (SE) in this population is unknown. Methods and results Accordingly, 547 consecutive patients (68 ± 4.9 years) with chest pain but no previous history of CAD, referred for SE (exercise and dobutamine), were identified. Patients were followed up for death and acute myocardial infarction (AMI). At a median follow-up period of 28 months, there were a total of 35 hard cardiac events (5 deaths and 30 non-fatal AMI). Among the prognostic clinical, resting/stress ECG, and SE data, univariate predictors were the Framingham risk score (P = 0.025), diabetes (P = 0.06), hypercholesterolaemia (P = 0.06), stress ECG ischaemia (P = 0.044), stress heart rate (P = 0.019), and SE-determined ischaemic burden (stress–rest wall thickening score index; P < 0.001). In a multivariate model, ischaemic burden was the only independent predictor of events (P < 0.001). SE also showed incremental prognostic value over and above clinical (Framingham's risk score) and stress ECG changes in a global χ2 model. This was true also for patients undergoing only exercise SE (n = 347). Conclusion SE provides both independent and incremental prognostic value for the prediction of hard cardiac events in chest pain patients without a previous history of CAD—over and above clinical, ECG, and stress ECG data. [ABSTRACT FROM AUTHOR]

We compared the cost effectiveness of recent approaches [coronary angiography and calcium scoring using computed tomography (CT) and stress magnetic resonance imaging (MRI)] to the diagnosis of coronary artery disease (CAD) with those of the traditional diagnostic modalities [conventional angiography (CATH), exercise ECG, and stress echocardiography] using a decision tree model. For patients with a 10% to 50% pretest likelihood of coronary artery disease, non-invasive coronary angiography using CT was the most cost effective approach, with costs per correctly identified CAD patient of euro4,435 (10% likelihood) to euro1,469 (50% likelihood). Only for a pretest likelihood of 30% to 40% was calcium scoring using CT more cost effective than any of the traditional diagnostic modalities, while MRI was not cost effective for any pretest likelihood. At a pretest likelihood of 60%, CT coronary angiography and CATH were equally effective, while CATH was most cost effective for a pretest likelihood of at least 70%. In conclusion, up to a pretest likelihood for coronary artery disease of 50%, CT coronary angiography is the most cost-effective procedure, being superior to the other new modalities and the most commonly used traditional diagnostic modalities. With a very high likelihood for disease (above 60%), CATH is the most effective procedure from the perspective of society. [ABSTRACT FROM AUTHOR]

Background: There are no reliable non-invasive markers of restenosis after percutaneous transluminal coronary angioplasty (PTCA). The aim of our study was to measure changes in QT interval dispersion after PTCA and to determine whether restenosis subsequently affects QT interval dispersion. Methods and Results: Fifty-six consecutive patients – 41 men and 15 women (mean age: 56.2 ±8.3 years) – with isolated stenosis of the left anterior descending artery who underwent successful PTCA were studied. A symptom-limited treadmill exercise test was performed within 7 days after PTCA and then again before repeated angiography. Repeated coronary angiography revealed restenosis in 15 patients (26.8%) and no signs of significant stenosis in 41 patients (73.2%). QT interval dispersion in the group of patients with restenosis measured before exercise increased from baseline 34 ± 7 to 49 ± 15 ms after 6 months (p < 0.01) and QT interval dispersion measured immediately after exercise increased from baseline 38 ± 4 to 68 ± 21 ms after 6 months (p < 0.001). In contrast, patients without restenosis showed no significant changes in QT interval dispersion measured before (baseline: 34 ± 9 ms; after 6 months 33 ± 12 ms; p = NS) and immediately after exercise (baseline: 34 ± 12 ms; after 6 months: 33 ± 10; p = NS). When QT interval dispersion ≥60 ms (measured 6 months after PTCA procedure) was considered as a potential marker of restenosis, this indicator had very high sensitivity and specificity when measured immediately after exercise (80 and 95% respectively). Conclusions: QT interval dispersion significantly increases in the group of patients with documented restenosis and may be a simple, non-invasive marker of restenosis. However, further studies are needed to confirm this observation. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background . We evaluated the value of coronary artery calcification (CAC) score in coronary artery disease (CAD) detection in asymptomatic hemodialysis (HD) patients by evaluating the association among CAC score, exercise electrocardiography (EECG), and Thallium-201 dipyridamole scintigraphy. Correlation between aortic pulse wave velocity (PWV) and CAC score was also evaluated. Methods . CAC score was assessed with conventional computed tomography in 40 patients. Thirty patients completed EECG and 25; those with a positive CAC score and/or a positive EECG performed Thallium dipyridamole scintigraphy. Carotid-femoral PWV was assessed in all patients. Results . There was no association among CAC score and EECG or Thallium dipyridamole scintigraphy. In contrast, CAC score was correlated with aortic PWV. Conclusion . The previous results question the role of CAC score in the detection of CAD in asymptomatic HD patients. The correlation between CAC score and aortic PWV raises the possibility that CAC score represents more an indicator of coronary artery medial wall calcification than a marker of CAD. [ABSTRACT FROM AUTHOR]

Background Exercise testing after acute myocardial infarction has limited prognostic accuracy. We prospectively used stress-recovery, heart rate-adjusted, ST-segment analysis to predict cardiac death in this clinical setting. [ABSTRACT FROM PUBLISHER]

Background Patients with known or suspected coronary disease are often investigated to facilitate risk assessment. We sought to examine the cost-effectiveness of strategies based on exercise echocardiography and exercise electrocardiography.Methods and results We studied 7656 patients undergoing exercise testing; of whom half underwent exercise echocardiography. Risk was defined with the Duke treadmill score for those undergoing exercise electrocardiography alone, and by the extent of ischaemia by exercise echocardiography. Cox proportional hazards models, risk adjusted for pretest likelihood of coronary artery disease, were used to estimate time to cardiac death or myocardial infarction. Costs (including diagnostic and revascularisation procedures, hospitalisations, and events) were calculated, inflation-corrected to year 2000 using Medicare trust fund rates and discounted at a rate of 5%. A decision model was employed to assess the marginal cost effectiveness (cost/life year saved) of exercise echo compared with exercise electrocardiography. Exercise echocardiography identified more patients as low-risk (51% vs 24%, p<0.001), and fewer as intermediate- (27% vs 51%, p<0.001) and high-risk (22% vs 4%); survival was greater in low- and intermediate-risk and less in high-risk patients. Although initial procedural costs and revascularisation costs (in intermediate-high risk patients) were greater, exercise echocardiography was associated with a greater incremental life expectancy (0.2 years) and a lower use of additional diagnostic procedures when compared with exercise electrocardiography (especially in lower risk patients). Using decision analysis, exercise echocardiography (∈2615/life year saved) was more cost effective than exercise electrocardiography.Conclusion Exercise echocardiography may enhance cost-effectiveness for the detection and management of at risk patients with known or suspected coronary disease. [ABSTRACT FROM PUBLISHER]

Noninvasive cardiokymography has been further developed to be able to record wall motion abnormalities during exercise. The study was designed to evaluate the diagnostic accuracy of stress cardiokymography and electrocardiography in the diagnosis of coronary artery disease. 223 patients were included in a prospective investigation using a newly developed computerized cardiokymography device. Sensitivity, specificity, and positive predictive value were 61, 69 and 90% for exercise cardiokymography, and 57, 74 and 91% for exercise electrocardiography, respectively. There was no statistically significant difference between cardiokymography and electrocardiography. The combination of electrocardiography and cardiokymography did not produce a significant improvement in diagnostic accuracy in comparison to exercise electrocardiography alone.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Abnormal heart rate (HR) recovery at 1 min after exercise (≤12 beats) was recently suggested to be a predictor of all cause and cardiac mortality. Aim: This study aimed to (1) correlate HR recovery at 1 min after exercise with known exercise and myocardial perfusion markers of increased cardiac mortality, and (2) compare the known exercise and myocardial perfusion markers of increased cardiac mortality between patients with a normal and abnormal HR recovery at 1 min after exercise. Methods: One hundred patients with known or suspected coronary artery disease referred for exercise stress testing (ETT) were prospectively enrolled. Percent, ETT time peak HR, HR reserve, summed stress score (SSS), extent of stress (SE%) and reversible perfusion abnormalities (RE%) were recorded in every patient. Results: There was poor correlation with markers of myocardial ischemia or infarction [SSS (r = 0.15), SE% (r = 0.05), RE% (r = 0.12), all p = n.s.] but highly significant correlation between HR recovery at 1 min after exercise and chronotropic variables [ETT time (r = 0.56), peak HR (r = 0.65), HR reserve % (r = 0.64), all p < 0.001]. Patients on β-blockers had significantly more incidence of an abnormal HR recovery at 1 min after exercise, compared to patients not on β-blockers (88 vs. 56%, p < 0.01). Conclusion: Abnormal HR recovery at 1 min after exercise has no correlation with known myocardial perfusion markers of increased cardiac mortality. Patients with an abnormal HR recovery do not appear to have an increased incidence or more severe myocardial infarction or ischemia. However, there is a strong correlation between HR recovery at 1 min after exercise and the chronotropic variables during exercise.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Myocardial perfusion imaging (MPI) with technetium-99m-labeled sestamibi and exercise electrocardiography (EECG) are widely used for risk stratification of patients with known or suspected coronary artery disease (CAD). However, no large-scale studies have addressed the prognostic power of the combined information from these diagnostic tools.Methods and Results: We studied 697 consecutive patients who underwent a 2-day Tc-99m sestamibi cardiac perfusion imaging protocol. The EECG was performed on a bicycle ergometer by symptom-limited exercise. Causes of death were obtained from death certificates. Univariate survival analyses were performed with a Kaplan-Meier estimate and a corresponding log-rank test. A multivariate Cox proportional hazards model was applied to test for potential predictor covariates obtained from hospital records. The predominant risk factors of cardiac death were fixed perfusion defects (relative risk, 2.55; range, 1.43 to 4.55) and an impaired circulatory exercise response (relative risk, 3.26; range, 1.74 to 6.08). The major prognostic information of MPI was the ability to detect patients with a definitively low risk. Patients with impaired circulatory response to exercise test and fixed perfusion defects were at a very high risk.Conclusion: The combined results of MPI and EECG provide substantial information on the long-term risk of cardiac death in patients with suspected CAD. [ABSTRACT FROM AUTHOR]

The response to a standardized angina and infarction questionnaire, the occurrence of coded resting and postexercise ECG findings suggestive of coronary heart disease (CHD), and blood pressure were studied among 417 male Japanese and 237 Finnish workers exposed occupationally to carbon disulfide (CS) and their controls, 391 Japanese and 233 Finnish men without such exposure. All of the subjects were aged 35 to 54 years. Among the Japanese subjects only seven exposed and one unexposed worker had a history of angina; typical angina was present in two exposed and in none of the unexposed men; and one had a history of possible myocardial infarction. In the Finnish exposed and unexposed groups the prevalence were 15 and 10% for total angina, and 4 and 4% for typical angina, respectively. No impressive differences emerged in the prevalences of 'coronary' ECG items between the exposed and unexposed groups. The presence of 'coronary' ECG findings was no more frequent in those with a history of angina than in those workers without such findings. None of the exposed and unexposed Japanese subjects with 'coronary' ECG changes gave history of angina or infarction. The 'coronary' ECG prevalences for the Finnish exposed and unexposed men were 30 and 24%. If a history of angina together with 'coronary' ECG abnormalities are taken as evidence of probable CHD, the total prevalence among the Japanese was 0 % for both the exposed and the unexposed group; and among the Finns, 5 and 2%, respectively. Smoking history, obesity, and blood pressure showed no marked differences in the Japanese groups. The diastolic and systolic blood pressure were significantly higher among the exposed Finnish workers than among the controls. The study yielded no evidence for an increased occurrence of the examined parameters among the Japanese workers exposed to carbon disulfide, whereas the exposure seemed causally associated with excess angina and high blood pressure among the Finns. The potential CHD induced by CS seemed to be undetectable by means of electrocardiography. [ABSTRACT FROM AUTHOR]

Simultaneous two-channel Holter monitoring, with a direct recording system, and maximal exercise testing with a 12-lead precordial electrocardiographic mapping system were performed in 50 patients with chest pain (41 with documented coronary artery disease, 9 without). The exploring Holter leads were placed to correspond to CM5 and an aVF-like lead. In 36 patients, ST segment changes were found with both Holter and the 12-lead precordial electrocardiogram, while in 12 patients no ischaemic changes were detected by either method. Thus the results of the two methods concurred in 48 of 50 patient (96%). The magnitude of the ischaemic change was similar in 24 of 36 patients (67%), while the Holter system underestimated the ischaemic change by 0.5–2.0 mm in 12 patients. When the maximal ST segment deviation in V5 was compared with CM5, the deviations with both systems were identical in all but one patient in whom a difference of 0.5 mm was found. The use of a Holter lead resembling aVF identified maximal ST segment change on only one occasion, and in only four patients was an ST segment change of 1 mm noted. In conclusion, ambulatory monitoring utilizing only CM5 seems to detect most episodes with ST segment changes, but the use of a 12-lead precordial mapping system during exercise testing may expand the possibility of defining the optimal sites for the exploring Holter leads to detect maximal ST segment change. [ABSTRACT FROM PUBLISHER]

The value of a predischarge exercise test combined with thallium-201 myocardial scintigraphy in detecting patients with severe multivessel disease (MVD) was studied in 58 consecutive patients discharged after a first acute myocardial infarction. Twelve electrocardiographic, clinical and scintigraphic variables were analysed. Angiography at one month revealed MVD (>70% narrowing in vessels unrelated to infarction) in 26 patients (45%). ST segment depression of I mm or greater, thallium defects in multiple vascular distributions (MVTL), and reversible thallium defects in a vascular distribution different from the infarct related vessel predicted patients at risk for MVD (predictive value respectively of 68%, 65% and 75%). The other variables were not significantly associated with the presence of MVD. Only ST segment depression and thallium defects in multiple vascular distributions emerged as independent predictors of MVD. Their combination yielded a 77% sensitivity and a 59% specificity for MVD. Combination of thallium imaging with the predischarge exercise ECG significantly improved the stratification provided by the exercise test alone (P<0.05). A positive thallium scan (MVTldefects) associated with a positive ECG (ST depression) carried a risk for MVD of 80% in the population studied. When both tests were negative, MVD was infrequent (risk 22%). Because improvement in the stratification of patients is not as clear as expectedfrom studies performed at a later stage, it appears that exercise thallium scintigraphy at a submaximal level one or two weeks after infarction does not provide optimal information. Predischarge exercise thallium-201 scintigraphy, however, superior to an exercise tolerance test alone in separating patients into those with high and low risk of MVD. [ABSTRACT FROM PUBLISHER]

Objectives. We addressed the question whether in patients with cardiac chest pain referred for stress myocardial perfusion scintigraphy, Tc-99m MIBI SPECT stress imaging should always be followed by a rest imaging procedure. Background. Using Tc-99m MIBI imaging a stress-rest sequence is usually performed implying that the resting study always follows the stress study irrespective of the results of the stress study. As a normal stress study would eliminate a subsequent resting study, it appears desirable to potentially define certain subsets of patients in whom a normal stress study can be expected in order to determine a more selective referral approach to the nuclear medicine department. The consequences of such a more streamlined approach would less impose on the logistics of the department of nuclear medicine, with decrease of investigation time, radiation dose, and costs in a time of retrenchment in the medical sector. Methods. A consecutive series of 460 patients (mean age 58.2 years) was studied who were stratified to 269 patients without prior myocardial infarction, and to 191 patients with documented evidence of a previously sustained mycoardial infarction. All patients underwent Tc-99m MIBI SPECT imaging according to a two-day stress-rest protocol. Results. Patients with and without a previous myocardial infarction showed suboptimal overall predictive accuracies for the exercise electrocardiograms (58% and 60%, respectively). In the total group of 460 patients, 94 (20%) patients showed a normal stress-rest Tc-99m MIBI SPECT; this occurred in 86/269 (32%) patients without a previous myocardial infarction and in only 8/191 (4%) patients with a previous myocardial infarction. Conclusions. Patients with a stress defect at Tc-99m MIBI SPECT imaging should always undergo a resting SPECT study irrespective of the clinical and stress electrocardiographic findings. As patients without a previous myocardial infarction had a normal stress SPECT study in almost one-third (32%) of patients compared to only 4% in patients with a previous myocardial infarction, it may be useful to employ different referral and imaging strategies i.e. a stress-only versus a stress-rest procedure. To schedule referring patients differently according to the presence or absence of a previously sustained myocardial infarction may be cost-saving, less demanding for the nuclear medicine personnel, and patient-convenient. In addition, a stress-only imaging procedure reduces radiation exposure to the individual patient. [ABSTRACT FROM AUTHOR]

The effect of coronary artery bypass surgery (CAB) on ventricular arrhythmias (VA) was studied in a prospective investigation involving 32 patients (mean age 54 years) who underwent CAB because of severe stable angina pectoris. Prior to CAB as well as 12 months later each patient was subjected to the following investigational programme: resting ECG, exercise ECG, 24-h ECG, selective coronary arteriography, ventriculography and cardiac catheterization. Exercise ECG showed VA in only three patients. The prevalence of VA during 24-h ECG was 56 and 66% on the two occasions (NS), while complicated VA (multiform, repetitive, R on T) was seen in 18 and 28%, respectively (NS). The persistence (number of 6-h periods showing VA) was 33 and 47% with regard to any VA (P<0.05), while complicated VA occurred in 13 and 15% of the 6-h periods (NS). Except for an increase in dp/dt/P at the postoperative measurement (P<0.05), no significant change in the performance of the left ventricle was seen after CAB though the graft patency was 77%. It is concluded that in patients with ‘medically intractable’ stable angina pectoris, CAB does not effect the occurrence of VA to any great extent — probably because left ventricular function is unchanged one year after as compared with that prior to CAB. [ABSTRACT FROM PUBLISHER]

Ninety-two patients (15 devoid of coronary artery disease, 24 with atherosclerotic coronary lesions but without antecedent myocardial infarction, 20 with prior anterior myocardial infarction, 33 with prior inferior infarction) were submitted to a stress electrocardiogram and thallium201 scan within the three months preceeding or the month following a coronary angiogram. This study first confirmed that by using a segmental analysis of the scans, the localization of the coronary lesion responsible for the appearance of zones of hypofixation can be determined. In general, however, defects appear only in the territory of the most stenosed vessels. For the detection of coronary disease in the absence of antecedent myocardial infarction, the exercise electrocardiogram showed a sensitivity of 54% and a specificity of 67%. The sensitivity (92%) and specificity (93%) of stress myocardial scintigraphy were clearly superior. Stress thallium201 scintigraphy detected 60% of the patients with anterior infarction and multiple vessel disease, but suggested the existence of multiple lesions in three out of five subjects with isolated LAD disease. After inferior infarction, multiple vessel disease was detected by scintigraphy with a sensitivity of 45% and a specificity of 82%. If an apical defect in the anterior view was considered to be the sign of LAD artery stenosis, the sensitivity of stress myocardial scintigraphy for the detection of multiple vessel disease in the presence of inferior myocardial infarction reached 86% and the specificity 54%. Stress thallium myocardial scintigraphy appears more sensitive and specific than exercise electrocardiography for the detection of coronary artery disease and residual ischaemia after myocardial infarction. [ABSTRACT FROM PUBLISHER]

Four dynamic tests of cardiac function were compared in a group of 13 long-standing insulin-dependent diabetics who had no clinical evidence of cardio-respiratory disease. One patient developed abnormal features during 24 hour ambulatory electrocardiograms while all 13 patients had normal exercise electrocardiograms. The change in left ventricular ejection fraction during dynamic supine exercise as measured by gated blood-pool scintigraphy was not significantly different from control subjects (p<0.1) while during cold stimulation testing the change in left ventricular ejection fraction in the diabetics was highly significantly different from the control subjects (p<0.01). Five of the patients had one or more abnormal tests of autonomic function. The cold stimulation test may be a sensitive index of cardiac dysfunction in diabetics but as the mechanism is unclear alternative explanations are possible. While the etiology of heart disease in such patients is uncertain it is likely to be multifactorial and this test may prove useful in investigating the natural history and pathogenesis of cardiac disease in diabetics. [ABSTRACT FROM AUTHOR]

In this study the use of exercise electrocardiography, by 47 general practitioners in South East Kent has been evaluated. Of 110 consecutive requests the majority (88%) were for diagnostic purposes, while only 7% were for prognostic assessment. Many of those referred were young or had non-cardiac chest pain and in 59% of cases the test result was unlikely to alter the clinical assessment of the probability of ischaemic heart disease (IHD). The test result influenced patient management in 85% of cases. Only 15% of patients were subsequently referred to the district general hospital although all had been considered for referral prior to the test. Although referral for invasive investigation of six patients was expedited by the provision of stress testing, in five patients general practitioners failed to consider any further investigation despite the patient having a strongly positive test. General practitioners use exercise electrocardiography primarily to exclude IHD in patients at low risk and provide reassurance. They rarely use the test as a means to guide management of those with known or probable IHD. [ABSTRACT FROM AUTHOR]

Purpose of Review: To provide an overview of recent studies of coronary computed tomography angiography (CCTA) and how it has helped to improve clinical outcomes for patients presenting with chest pain. Recent Findings: Randomised controlled trials have uniformly demonstrated that the use of CCTA is associated with improvements in patient diagnosis, management and treatments as well as the avoidance of unnecessary invasive coronary angiography. These changes have been associated with consistent reductions in long-term rates of fatal or non-fatal myocardial infarction. Summary: Major beneficial effects in clinical management and patient outcomes are seen with the use of coronary computed tomography angiography. CCTA might be considered to be the first test of choice for the investigation of coronary heart disease. [ABSTRACT FROM AUTHOR]