Exercise Exercise Electrocardiogram Research Articles

Exercise Test Predicts Both Noncardiovascular and Cardiovascular Death in a Primary Prevention Population

ObjectiveTo identify specific causes of death and determine the prevalence of noncardiovascular (non-CV) deaths in an exercise test referral population while testing whether exercise test parameters predict non-CV as well as CV deaths. Patients and MethodsNon-imaging exercise tests on patients 30 to 79 years of age from September 1993 to December 2010 were reviewed. Patients with baseline CV diseases and non-Minnesota residents were excluded. Mortality through January 2016 was obtained through Mayo Clinic Records and the Minnesota Death Index. Exercise test abnormalities included low functional aerobic capacity (ie, less than 80%), heart rate recovery (ie, less than 13 beats/min), low chronotropic index (ie, less than 0.8), and abnormal exercise electrocardiogram (ECG) of greater than or equal to 1.0 mm ST depression or elevation. We also combined these four abnormalities into a composite exercise test score (EX_SCORE). Statistical analyses consisted of Cox regression adjusted for age, sex, diabetes, hypertension, obesity, current and past smoking, and heart rate–lowering drug. ResultsThe study identified 13,382 patients (females: n=4736, 35.4%, 50.5±10.5 years of age). During 12.7±5.0 years of follow-up, there were 849 deaths (6.3%); of these 162 (19.1%) were from CV; 687 (80.9%) were non-CV. Hazard ratios for non-CV death were significant for low functional aerobic capacity (HR, 1.42; 95% CI, 1.19 to 1.69; P<.0001), abnormal heart rate recovery (HR, 1.36; 95% CI, 1.15 to 1.61; P<.0033), and low chronotropic index (HR, 1.49; 95% CI, 1.26 to 1.77; P<.0001), whereas abnormal exercise ECG was not significant. All exercise test abnormalities including EX_SCORE were more strongly associated with CV death versus non-CV death except abnormal exercise ECG. ConclusionNon-CV deaths predominated in this primary prevention cohort. Exercise test abnormalities not only predicted CV death but also non-CV death.

Optimising screening of intermediate to high-risk asymptomatic sportsmen with exercise electrocardiogram. The SEEPRED study

Abstract Funding Acknowledgements Type of funding sources: None. Background The importance of exercise electrocardiogram (ECG) is still controversial in the prevention of cardiovascular events among sportsmen. The aim of this study was to assess the relevance of exercise ECG as a significant prognostic marker for cardiovascular events when any CVD risk factors are present. Methods The SEEPRED cohort study included leisure time asymptomatic sportsmen over 35 years old, referred from 2011 to 2016 in the Sports Medicine Unit of our university hospital. Major adverse cardiovascular events (MACE) and atrial fibrillation were collected 5 years after exercise ECG using a phone questionnaire. Multivariate logistic regression models were performed to predict positive exercise ECG, suspected and confirmed silent myocardial ischemia (SMI) and cardiovascular events. Results Of the cohort of 2457 sportsmen (1898 men; mean age 50.2 ± 9.4 years; physical activity level 29.4 ± 25.1 MET-h/week), 1482 (60%) had at least one cardiovascular disease (CVD) risk factor and 52 (2%) had a SCORE&amp;gt;5%. A total of 256 exercise ECGs (10%) were defined as positive, most of them due to SMI (n = 196; 8%). SMI was an indication for coronary angiography in 43 cases, leading to 33 documented SMIs (1%), including 23 significant stenoses requiring revascularization. In multivariate logistic regression analysis, having at least 2 CVD risk factors was independently associated with (1) positive exercise ECG [OR=1.80 (CI 95%: 1.29-2.52), p=0.0006], with (2) suspected SMI [OR=2.57 (CI 95%: 1.10-6.02), p=0.0304], with (3) confirmed SMI [OR=8.20 (CI 95%: 3.46-19.46), p&amp;lt;0.0001] and with (4) cardiovascular events (MACE or atrial fibrillation) [OR=6.95 (CI 95%: 3.49-13.81), p&amp;lt;0.0001]. Conclusions The study supports the European recommendations for the use of exercise ECG in evaluation of asymptomatic leisure time sportsmen over 35 years. Having at least 2 CVD risk factors was the best predictors for presence of coronary lesions at risk for events.

Cardiovascular Autonomic Function Changes and Predictors During a 2-Year Physical Activity Program in Rheumatoid Arthritis: A PARA 2010 Substudy.

Background: Chronic inflammation leads to autonomic dysfunction, which may contribute to the increased risk of cardiovascular diseases (CVD) in patients with rheumatoid arthritis (RA). Exercise is known to restore autonomic nervous system (ANS) activity and particularly its parasympathetic component. A practical clinical tool to assess autonomic function, and in particular parasympathetic tone, is heart rate recovery (HRR). The aim of this substudy from the prospective PARA 2010 study was to determine changes in HRR post-maximal exercise electrocardiogram (ECG) after a 2-year physical activity program and to determine the main predictive factors associated with effects on HRR in RA.Methods: Twenty-five participants performed physiotherapist-guided aerobic and muscle-strengthening exercises for 1 year and were instructed to continue the unsupervised physical activity program autonomously in the next year. All participants were examined at baseline and at years 1 and 2 with a maximal exercise ECG on a cycle ergometer. HRR was measured at 1, 2, 3, 4, and 5 min following peak heart rate during exercise. Machine-learning algorithms with the elastic net linear regression models were performed to predict changes in HRR1 and HRR2 at 1 year and 2 years of the PARA program.Results: Mean age was 60 years, range of 41–73 years (88% women). Both HRR1 and HRR2 increased significantly from baseline to year 1 with guided physical activity and decreased significantly from year 1 to year 2 with unsupervised physical activity. Blood pressure response to exercise, low BMI, and muscular strength were the best predictors of HRR1/HRR2 increase during the first year and HRR1/HRR2 decrease during the second year of the PARA program.Conclusion: ANS activity in RA assessed by HRR was improved by guided physical activity, and machine learning allowed to identify predictors of the HRR response at the different time points. HRR could be a relevant marker of the effectiveness of physical activity recommended in patients with RA at high risk of CVD. Very inactive and/or high CVD risk RA patients may get substantial benefits from a physical activity program.

A DETECTION SYSTEM OF EXERCISE ELECTROCARDIOGRAM

ABSTRACT Introduction: A new exercise electrocardiogram (ECG) detection system was investigated in this study to diagnose and analyze cardiopulmonary function and related diseases in a comprehensive and timely manner and improve the accuracy of diagnosis. Besides, its reliability and clinical applicability were judged. Objective: A new type of exercise ECG detection system was constructed by adding parameters such as respiratory mechanics, carbon dioxide, and oxygen concentration monitoring based on the traditional ECG detection system. Methods: The new system constructed in this study carried out the ECG signal detection, ECG acquisition module, blood pressure and respiratory mechanics detection and conducted a standard conformance test. Results: The heart rate accuracy detected by the exercise ECG system was greatly higher than that of the doctor's manual detection (P &lt; 0.05). The accuracy of the new exercise ECG detection system increased obviously in contrast to that of the manual detection result (P &lt; 0.05). The key technical index input noise and input impedance test results (24.5 μV and 12.4 MΩ) of the exercise ECG detection system conformed to the standard (&lt; 30 μV and &gt; 2.5 MΩ). The common-mode rejection and sampling rate test results (103.5 dB and 515 Hz) of key technical indicators in the exercise ECG detection system were all in line with the standards (≥89 dB and ≥500 Hz). Conclusion: The complete exercise ECG detection system was constructed through the ECG acquisition module, blood pressure detection, and respiratory mechanics detection module. In addition, this system could be applied to detect ECG monitoring indicators with high accuracy and reliability, which could also be extensively adopted in clinical diagnosis. Level of evidence II; Therapeutic studies - investigation of treatment results.

A Real-Time QRS Detection Algorithm Based on Energy Segmentation for Exercise Electrocardiogram

Motion artifact is widely present in exercise electrocardiogram (ECG) signal, which is an important factor affecting the accuracy of QRS complex detection. A simple-fast QRS detection algorithm based on energy segmentation is proposed, which is suitable for exercise ECG measured by the wearable monitoring device. The proposed method mainly consists of four parts: the 15–25 Hz band-pass filter, the calculation of segmentation energy, the moving average filter and the detection of R-peaks. To enhance the information of the QRS complex, a band-pass filter is used to eliminate noises and suppress unwanted P/T waves. The information of R-R interval and QRS duration is used to energy segmentation, and moving average filter is used to obtain the adaptive energy threshold. Then, an algorithm combined adaptive energy threshold with amplitude threshold is used for QRS detection. The MIT-BIH arrhythmia database and the European ST-T database are chosen to value the correctness of the algorithm. The motion artifact contaminated ECG database is chosen to value the robustness. Exercise ECG signals obtained by lab are used to value the practicality of the algorithm. The simulation results show that the QRS detection algorithm has a sensitivity of 99.36%, a positive predictivity of 99.78%, an accuracy of 99.14%, and performs well even under ECG signal contaminated by strong motion artifacts.

Electronic textile-based electrocardiogram monitoring in cardiac patients: a scoping review.

The objectives of this scoping review were to explore, organize and present the existing research literature on the use of electronic textile (e-textile)-based resting, signal-averaged, ambulatory or exercise electrocardiogram (ECG) monitoring to evaluate the application of e-textile technologies for ECG cardiac monitoring. E-textile-based ECG monitoring of cardiac patients offers a possible new alternative for in-hospital monitoring and post-discharge monitoring during cardiac rehabilitation. Studies that included patients (inpatients or outpatients) who qualified for cardiac rehabilitation programs or continuous ambulatory ECG monitoring were considered. The key concepts that were addressed included resting, signal-averaged, ambulatory or exercise ECG monitoring based on e-textile technologies or e-textile-based cardiac rehabilitation. Studies were excluded if they focused only on specific aspects of the e-textile ECG system rather than a complete ECG system. Research reports, dissertations or books that evaluated e-textile-based ECG monitoring of cardiac patients in a hospital or at home, written in English, and published between January 2000 and March 2018 were considered for inclusion. Published and unpublished literature was located through databases including Ovid Medical Literature Analysis and Retrieval System Online (MEDLINE), PubMed Central (PMC), Institute of Electrical and Electronics Engineers (IEEE Xplore), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Database of Systematic Reviews, Web of Science, Scopus, Expanded Academic ASAP, ProQuest Dissertations and Theses Global, SPORTDiscus, and ENGINE-Australian Engineering Database (Informit). Two independent reviewers screened citations for inclusion while the third reviewer resolved any discrepancies. Meta-data from each study were extracted, and a narrative summary was used to present the results. Furthermore, 38 study authors were contacted to request missing or additional data as required, with 16 responding within eight weeks. Of the 207 studies that were eligible for full-text review, only 8% (n = 17) were included in the final study. Eighty-eight percent (n = 15) of included studies were conducted with an adult population, and 11 studies reported an in-hospital application. Only three groups of researchers reported e-textile integration beyond the textile electrodes, mostly in the form of wiring and custom-made printed circuit boards. Eight studies utilized two ECG sensors, while single-lead ECG was the most common configuration, used in 10 studies. ECG result was the primary parameter reported across the included studies. Resting ECG was the most common form of ECG acquired (n = 10), followed by exercise ECG (n = 6) and ambulatory ECG (n = 5). Eight studies addressed the issue of power requirements, and seven studies used Bluetooth for wireless communication. The primary problem reported across all studies was noise from motion artifact. The recent advances in signal quality and noise reduction for e-textile-based ECG applications are promising. However, the use of a 12-lead, personalized, home-based cardiac rehabilitation monitor system containing fully textile-integrated electronics with diagnostic capability is yet to be reported. Therefore, there is potential for future research in this area. Additionally, motion artifact continues to be a challenge.

Exercise electrocardiogram testing in asymptomatic patient with type 2 diabetes and left ventricular diastolic dysfunction

Background: Type 2 diabetes mellitus (DM) is an established risk factor for cardiovascular events and the development of congestive heart failure (HF). Diastolic dysfunction is considered a precursor of HF and may be diagnosed noninvasively by echocardiography. Diastolic dysfunction is common in well-controlled type 2 diabetic patients without clinically detectable heart disease. Left ventricular diastolic dysfunction represents the earliest preclinical dysfunction and that it can progress to asymptomatic HF. Aim of the Work: The aim of the study is to evaluate if diastolic dysfunction in diabetic patients is due to silent ischemia. Methods: This study included 80 asymptomatic patients with type 2 DM. Echocardiography was done to all patients to assess systolic and diastolic functions. Exercise electrocardiogram (ECG) was done for all patients to detect ischemic heart disease. Coronary angiography was done to patients with positive exercise ECG test. Results: The incidence of diastolic dysfunction was 75%; among the studied groups. Impaired relaxation was detected in 87 % and pseudo normal pattern was detected in 13 % of subjects with diastolic dysfunction. Patients with normal diastolic function had negative stress exercise test, while those with diastolic dysfunction, 12 patients had positive exercise stress ECG (40%) and 18 patients had negative exercise stress ECG (60%). Conclusion: These findings indicate that coronary artery disease is not uncommon in diabetic patients with diastolic dysfunction and increase markedly in patients with positive stress exercise electrocardiography.

Electrocardiographic abnormalities in amateur male marathon runners.

Sports activity has become extremely popular among amateurs. Electrocardiography is a useful tool in screening for cardiac pathologies in athletes; however, there is little data on electrocardiographic abnormalities in the group of amateur athletes. The aim of this study was to analyze the abnormalities in resting and exercise electrocardiograms (ECGs) in a group of amateur athletes, and try to determine whether the criteria applied for the general population or for athletes' ECGs should be implemented in this group. In 40 amateur male marathon runners, 3 consecutive 12-lead ECGs were performed: 2-3 weeks before (stage 1), just after the run (stage 2) and 2-3 weeks after the marathon (stage 3). Resting (stage 1) and exercise (stage 2) ECGs were analyzed following the refined criteria for the assessment of athlete's ECG (changes classified as training-related, borderline or training-unrelated). In resting ECGs, at least 1 abnormality was found in 92.5% of the subjects and the most common was sinus bradycardia (62.5%). In post-exercise ECGs, at least 1 abnormality was present in 77.5% of the subjects and the most common was right atrium enlargement (RAE) (42.5%). Training-related ECG variants were more frequent at rest (82.5% vs 42.5%; p = 0.0008), while borderline variants - after the run (22.5% vs 57.5%; p = 0.0004). Training-unrelated abnormalities were found in 15% and 10% of the subjects, respectively (p-value - nonsignificant), and the most common was T-wave inversion. Even if the refined criteria rather than the criteria used for normal sedentary population were applied, the vast majority of amateur runners showed at least 1 abnormality in resting ECGs, which were mainly training-related variants. However, at rest, in 15% of the subjects, pathologic training-unrelated abnormalities were found. The most frequent post-exercise abnormality was right atrial enlargement. General electrocardiographic screening in amateur athletes should be taken into consideration.

Exercise electrocardiogram in middle-aged and older leisure time sportsmen: 100 exercise tests would be enough to identify one silent myocardial ischemia at risk for cardiac event

BackgroundThe importance of exercise electrocardiogram (ECG) has been controversial in the prevention of cardiac events among sportsmen. The aim of this study was to determine the frequency of silent myocardial ischemia (SMI) from an exercise ECG and its relationship with induced coronary angiographic assessment and potentially preventable cardiac events. MethodsThis prospective cohort study included leisure time asymptomatic sportsmen over 35years old, referred from 2011 to 2014 in the Sports Medicine Unit of the University Hospital of Saint-Etienne. ResultsOf the cohort of 1500 sportsmen (1205 men; mean age 50.7±9.4years; physical activity level 32.8±26.8MET-h/week), 951 (63%) had at least one cardiovascular disease (CVD) risk factor. Family history, medical examination and standard resting 12-lead were collected. A total of 163 exercise ECGs (10.9%) were defined as positive, most of them due to SMI (n=129, 8.6%). SMI was an indication for coronary angiography in 23 cases, leading to 17 documented SMIs (1.1%), including 11 significant stenoses requiring revascularization. In multivariate logistic regression analysis, a high risk of CVD (OR=2.65 [CI 95%: 1.33–5.27], p=0.005) and an age >50years (OR=2.71 [CI 95%: 1.65–4.44], p<0.0001) were independently associated with confirmed SMI. ConclusionsThe association of positive exercise ECG with significant coronary stenosis was stronger among sportsmen with CVD risk factors and older than 50years. Screening by exercise ECG can lower the risk of cardiac events in middle-aged and older sportsmen. One hundred tests would be enough to detect one silent myocardial ischemia at risk for cardiac event.

Increased myocardial energy expenditure in cardiac syndrome X: More work, more pain

The aim of this study was to assess the myocardial energy expenditure (MEE) in patients with cardiac syndrome X (CSX) and to examine its association with exercise electrocardiogram (ECG) parameters. A total of 99 patients who underwent coronary angiography and who were diagnosed as having normal coronary arteries were included. The patients were divided into 2 groups based on symptoms and exercise ECG parameters: 56 CSX patients and 43 control patients with a negative stress test. MEE was calculated using transthoracic echocardiography-derived parameters: circumferential end-systolic stress, left ventricular ejection time, and stroke volume. In patients with CSX, the MEE at rest was 28% higher in than the control group (89.2±36.3 vs. 69.8±17.2 cal/minute). Correlation analysis revealed a moderately negative correlation between MEE and the Duke treadmill score (DTS) (ß:-0.456; p<0.001). Receiver operating characteristic analysis with a cut-off value of 74.6 cal/minute for MEE had a sensitivity of 78.1% and a specificity of 75.3% for the prediction of CSX (area under the curve: 0.872; p<0.001). An extra 1 calorie spent per minute at rest increased the likelihood of CSX by about 86% (odds ratio: 1.863). This study demonstrated that MEE was greater in CSX patients compared with a control group. Increased MEE was determined to be an independent predictor of CSX. DTS was inversely correlated with MEE. Increased MEE may have a crucial role in CSX pathophysiology.

The value of predischarge exercise ECG testing in chest pain patients in the era of high-sensitivity troponins.

The aim of this study was to examine the value of predischarge exercise electrocardiogram (ECG) testing of chest pain patients in whom acute myocardial infarction (MI) had been ruled out by means of high-sensitivity troponins, ECG and history. All patients hospitalised for chest pain who underwent exercise ECG testing before discharge from the Department of Cardiology, Södersjukhuset, Stockholm, Sweden from January 2011 to June 2012 were included. Endpoints were death, MI and post-discharge revascularisation within 90 and 365 days, respectively. The background one-year risk of death and MI for a corresponding age, gender and calendar time-matched Swedish population was also examined. A total of 951 patients were included. In 585 patients (61.5%) the exercise ECG test was negative, in 94 (9.9%) positive and in 272 (28.6%) inconclusive. There were no significant differences regarding death or MI between patients with a positive or a negative test, neither at 90 ( n=1 (1.1%) vs. n=1 (0.2%)) nor at 365 days ( n=2 (2.1%) vs. n=4 (0.7%)) of follow-up. In total there were nine (0.9%) deaths and 10 (1.1%) MIs within 365 days. The one-year rates of death (1.3%) and MI (0.5%) in a matched Swedish population were comparable. Predischarge exercise ECG testing after rule out of MI did not predict subsequent death or MI in a population of patients hospitalised for chest pain. Furthermore, the risks of death and MI in this population were comparable to a matched Swedish population. These findings suggest that patients could be discharged without this test.

Coronary Microvascular Dysfunction Assessed by Intracoronary Acetylcholine Provocation Testing Is a Frequent Cause of Ischemia and Angina in Patients With Exercise‐Induced Electrocardiographic Changes and Unobstructed Coronary Arteries

The exercise electrocardiogram (ECG) is a standard examination in patients with suspected coronary artery disease. However, despite a pathologic result, many patients undergoing diagnostic coronary angiography do not have any significant epicardial stenosis. In this study, we assessed the relation between a pathologic exercise ECG and coronary microvascular dysfunction in response to intracoronary acetylcholine (ACh) provocation in patients without any relevant epicardial stenosis. Coronary microvascular dysfunction is significantly more often in patients with angina, unobstructed coronary arteries and a pathologic exercise stress test compared to those without pathologic stress test. This study recruited 137 consecutive patients with exertional angina pectoris who underwent diagnostic coronary angiography between September 2008 and April 2011 (68% women; mean age, 63 ± 10 years). In none of the patients was there a stenosis of >50%. All patients underwent an exercise ECG before angiography and intracoronary ACh provocation testing for assessment of coronary vasomotor responses directly after angiography. The exercise ECG showed an abnormal result in 69 patients (50%; ST-segment depression ≥0.1 mV and/or reproduction of the patient's usual symptoms). The ACh test revealed a coronary vasomotor abnormality (reproduction of the patient's symptoms, ischemic ECG shifts ± diffuse distal vasoconstriction) in 87 patients (64%). Such a result was significantly more often found in patients with a pathologic exercise ECG (50/69 [72%] vs 19/69 [28%], P = 0.034). There were no other statistically significant differences between patients with and those without pathologic exercise ECG. Coronary microvascular dysfunction is frequently found in patients with exertional angina pectoris and unobstructed coronary arteries. Such a finding is found significantly more often in presence of a pathologic exercise ECG.

Myocardial strain analysis by 2-dimensional speckle tracking echocardiography improves diagnostics of coronary artery stenosis in stable angina pectoris

Purpose: To determine if 2-Dimensional Strain Echocardiography (2DSE) performed at rest in patients with suspected Stable Angina Pectoris (SAP) is able to improve the diagnosis of the presence of significant Coronary Artery Disease (CAD). Methods: In total 296 consecutive patients with clinically suspected SAP, no previous cardiac history and a normal ejection fraction were included. All patients were examined by 2DSE, Exercise Electrocardiogram (ECG) and coronary angiography. 2DSE was performed in the three apical projections. Peak Regional Longitudinal Systolic strain (RLS) was measured in 18 myocardial sites and averaged to provide Global Longitudinal Systolic strain (GLS). Duke Score (DS), including ST-depression, chest pain and exercise capacity, was used as the outcome of the exercise ECG. Results: Patients with an area stenosis ≥70% in at least one epicardial coronary artery were categorized as having significant CAD (n=108). GLS was significantly lower in patients with CAD compared to patients without CAD (17.1% vs. 18.8%, p<0.001), and remained an independent predictor of CAD after multivariable adjustment for baseline data, exercise ECG and conventional echocardiographic parameters (OR 1.17 (1.0-1.3, p=0.012) per 1% decrease). Area under receiver operating characteristics curve (AUC) for exercise ECG and GLS in combination was significantly higher than AUC for exercise ECG alone (0.84 vs. 0.78, p<0.004). Furthermore, RLS predicted significant stenosis in corresponding coronary arteries (Figure 1). ![Figure][1] Figure 1. RLS in stenotic vs non-stenotic segments Conclusion: In patients with suspected SAP GLS at rest is an independent predictor of significant coronary artery disease and significantly improves the diagnostic performance of exercise ECG. Additionally, RLS can identify which coronary artery that suffers from significant stenosis. [1]: pending:yes

Risk scores prognostic implementation in patients with chest pain and nondiagnostic electrocardiograms

BackgroundSeveral risk scores are available for prognostic purpose in patients presenting with chest pain. AimThe aim of this study was to compare Grace, Pursuit, Thrombolysis in Myocardial Infarction (TIMI), Goldman, Sanchis, and Florence Prediction Rule (FPR) to exercise electrocardiogram (ECG), decision making, and outcome in the emergency setting. MethodsPatients with nondiagnostic ECGs and normal troponins and without history of coronary disease underwent exercise ECG. Patients with positive testing underwent coronary angiography; otherwise, they were discharged.End point was the composite of coronary stenosis at angiography or cardiovascular death, myocardial infarction, angina, and revascularization at 12-month follow-up. ResultsOf 508 patients considered, 320 had no history of coronary disease: 29 were unable to perform exercise testing, and finally, 291 were enrolled. Areas under the receiver operating characteristic curves for Grace, Pursuit, TIMI, Goldman, Sanchis, and FPR were 0.59, 0.68, 0.69, 0.543, 0.66, and 0.74, respectively (P < .05 FPR vs Goldman and Grace). In patients with negative exercise ECG and overall low risk score, only the FPR effectively succeeded in recognizing those who achieved the end point; in patients with high risk score, the additional presence of carotid stenosis and recurrent angina predicted the end point (odds ratio, 12 and 5, respectively). Overall, logistic regression analysis including exercise ECG, coronary risk factors, and risk scores showed that exercise ECG was an independent predictor of coronary events (P < .001). ConclusionsThe FPR effectively succeeds in ruling out coronary events in patients categorized with overall low risk score. Exercise ECG, nonetheless being an independent predictor of coronary events could be considered questionable in this subset of patients.

Tissue Doppler echocardiography improves the diagnosis of coronary artery stenosis in stable angina pectoris

Aim To determine if colour tissue Doppler imaging (TDI) performed at rest in patients with suspected stable angina pectoris (SAP) is able to predict the presence of significant coronary artery disease (CAD). This study comprises 296 consecutive patients with clinically suspected SAP, no previous cardiac history, and a normal ejection fraction. All patients were examined by colour TDI, exercise electrocardiogram (ECG), and coronary angiography (CAG). Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates. Duke score (DS), including ST depression, chest pain, and exercise capacity, was used as the outcome of the exercise ECG. Patients with an area stenosis of ≥70% in at least one epicardial coronary artery were categorized as having a significant CAD (n= 108) and were compared with patients without significant CAD (n= 188). Both e' [odds ratio (OR): 1.5 (1.1-1.9, P < 0.01) per cm/s decrease] and s' [OR: 1.7 (1.1-2.5, P < 0.05) per cm/s decrease] remained independent predictors of CAD after multivariable adjustment for baseline, exercise ECG, and conventional echocardiographic parameters. Area under the receiver operating characteristic curve (AUC) for exercise ECG and TDI in combination was significantly higher than AUC for exercise ECG alone (0.84 vs. 0.79, P < 0.01). In patients with suspected SAP colour TDI performed at rest is an independent predictor of significant CAD, and colour TDI improves the diagnostic performance of exercise ECG.

Abstract 8594: Rapid ST-upslope on Exercise Electrocardiogram Predicts Reduced Long Term Mortality from Coronary Heart Disease.

Aims The prognostic value of a rapid ST-upslope on exercise electrocardiogram (ECG) is unknown among healthy individuals, but it may be associated with a well-balanced control of the autonomic nervous system. We aim to test the hypothesis that rapid ST-upslope is associated with reduced risk of dying from coronary heart disease (CHD). Methods and results A group of healthy middle-aged men (n=2014) participated in a cardiovascular survey examination. They underwent an examination program including a symptom limited ECG bicycle exercise test. Exercise induced ST- segments were categorized in three groups: normal ST-segment (n=1383), rapid ST- upslope (n=401) and ST-depression (n=230). Survival analyses were adjusted for smoking status, total cholesterol, systolic blood pressure, maximal heart rate, and physical fitness. The rapid ST-upslope group was associated with a 30% decreased risk of CHD-death (Hazard Ratio (HR) = 0.70 [95%CI 0.51-0.95]) compared to the normal ST-segment group (see image below). The risk of CVD-death was numerically lower in the rapid ST-upslope group (0.82 [95%CI 0.65-1.04]) compared to the normal ST-segment group. The ST-depression group was associated with a 1.45-fold (HR = 1.45 [95%CI 1.09-1.90]) increased risk of CHD-death compared to the normal ST-segment group. Conclusions The rapid ST-upslope on exercise ECG was a common finding (20%) among healthy middle aged men and was associated with a 30% reduced risk of dying from CHD compared to individuals with normal ST-segment. We suggest that rapid ST-upslope on exercise ECG is the true healthy state.

Evidence Fails to Support ECG Screening for Those Without Heart Disease Symptoms

PHYSICIANSDOINGROUTINEPHYSICAL examinationsonolder individuals frequently call for a resting or exerciseelectrocardiogram(ECG)todetect heartabnormalities.Althoughscreening ECGsinasymptomaticindividualsdodetectabnormalitiesassociatedwithhigher riskforadversecardiovascularevents,rigorous evidence is lacking to determine whether such tests actuallychangeclinical actions and improve outcomes, said authors of a 2011 review (Chou R et al. Ann Intern Med. 2011;155[6]:375-385). The review, requested by the US PreventiveServicesTaskForce,reaffirmsthe 2004 recommendation by the task force againstscreeningwithrestingorexercise ECG in adults at low risk for coronary heart disease. Roger Chou, MD, lead author of the reviewandanassociateprofessorofmedicineatOregonHealth&ScienceUniversityinPortland,saidhisteam’smainfocus was to understand what added benefit ECG would provide over traditional Framingham risk assessment to physicians evaluating patients. Framingham riskassessment isbasedonascoringsystemthatcalculatesanindividual’s10-year percentage risk of myocardial infarction or coronary death based on age, sex, levels of total and high-density lipoprotein cholesterol, smoking status, and blood pressure readings. Individuals are stratified to 3 risk levels: low ( 10%), intermediate (10%-20%), or high ( 20%). The reviewers looked at 65 Englishlanguage articles published from 2002 through January 2011 and found that none addressed whether ECG screening improved outcomes, affected clinical decision making, or improved Framingham risk reclassification. They included 2 studies looking at direct harms from ECG screening and found the test safe. The 63 studies addressing ECG findings and risk for cardiovascular events showed that abnormalities on resting ECG or exercise ECG were associated with increased risk. “We wanted to understand how the ECG findings would affect clinical

The accuracy of the electrocardiogram during exercise stress test based on heart size.

BackgroundMultiple studies have shown that the exercise electrocardiogram (ECG) is less accurate for predicting ischemia, especially in women, and there is additional evidence to suggest that heart size may affect its diagnostic accuracy.HypothesisThe purpose of this investigation was to assess the diagnostic accuracy of the exercise ECG based on heart size.MethodsWe evaluated 1,011 consecutive patients who were referred for an exercise nuclear stress test. Patients were divided into two groups: small heart size defined as left ventricular end diastolic volume (LVEDV) <65 mL (Group A) and normal heart size defined as LVEDV ≥65 mL (Group B) and associations between ECG outcome (false positive vs. no false positive) and heart size (small vs. normal) were analyzed using the Chi square test for independence, with a Yates continuity correction. LVEDV calculations were performed via a computer-processing algorithm. SPECT myocardial perfusion imaging was used as the gold standard for the presence of coronary artery disease (CAD).ResultsSmall heart size was found in 142 patients, 123 female and 19 male patients. There was a significant association between ECG outcome and heart size (χ2 = 4.7, p = 0.03), where smaller hearts were associated with a significantly greater number of false positives.ConclusionsThis study suggests a possible explanation for the poor diagnostic accuracy of exercise stress testing, especially in women, as the overwhelming majority of patients with small heart size were women.

Prognostic value of demographic factors, pre-test probability scoring, exercise test diagnosis, and inability to exercise in patients with recent onset suspected cardiac chest pain

To assess the prognostic value of an inconclusive exercise test or inability to exercise in patients with recent onset suspected cardiac chest pain and to determine the independent predictors of events in these patients. This was an observational follow-up study of patients presenting to a rapid access chest pain clinic with a history of recent-onset suspected cardiac chest pain as referred by the family practitioner. The main outcome measure was a composite endpoint of death and acute coronary syndrome hospital admission. The study cohort consisted of 1851 patients in whom a total of 147 events were recorded during a mean follow-up period of 4.1 ± 1.1 years. Those with events were significantly older (65.1 ± 12.5 years versus 56.4 ± 13.2 years, p < 0.001), had higher mean pre-test probability of coronary artery disease (CAD), and had higher prevalence of diabetes (18.4% vs. 13.6%, p < 0.001), hypertension (55.8% vs. 38.7%, p < 0.001), and smoking (36.7% vs. 25.4%, p = 0.03) than those without events. These patients were also more likely to have a positive exercise electrocardiogram (ECG) (15.6% vs. 8.6%, p < 0.001) or not have a diagnostic exercise test because of an inconclusive result or inability to exercise (60.5% vs. 28.6%, p < 0.001). Cox multivariate regression analysis showed that age (hazard ratio, HR 1.03, p < 0.001), pre-test probability of CAD (HR 1.08, p = 0.04), positive exercise ECG (HR 2.94, p < 0.001), and an inconclusive test or inability to exercise (HR 3.45, p < 0.001) were independent predictors of events. In patients with recent onset suspected cardiac chest pain, not having a diagnostic exercise ECG because of an inconclusive test or inability to exercise is an independent predictor of events and has similar prognostic implications to a positive exercise ECG. In addition, pre-test probability estimation at baseline is a robust indicator of clinical outcome. Future models of care need to incorporate early and increased access to non-exercise cardiac imaging techniques in order to meet the needs of this high-risk subgroup of patients.

The Clinical Utility of Cardiopulmonary Exercise Testing in Suspected or Confirmed Myocardial Ischemia

Heart disease is a major cause of morbidity and mortality in the United States, with coronary artery disease (CAD) representing more than half of all cardiovascular events. Stable patients presenting with symptoms suggestive of CAD are likely to undergo an exercise electrocardiogram (ECG) and/ or imaging study as a first-line diagnostic assessment. A cardiopulmonary exercise test (CPX) is an ECG stress test plus ventilatory gas analysis. Recently, CPX has been used to detect exercise-induced myocardial ischemia (EIMI) suggestive of underlying CAD. Two CPX variables, oxygen pulse (VO2/HR) and the slope of oxygen consumption versus work rate (Δ VO2/ Δ WR), have been identified to be especially indicative of EIMI. Currently, there are a number of diagnostic tests available for the identification of CAD, with the most widely used being stress ECG, stress myocardial perfusion imaging (MPI) and echocardiography, and cardiac catheterization. Exercise ECG, although inexpensive, has a number of well-recognized limitations, including low sensitivity resulting in false-negative results. Stress (exercise or pharmaceutically induced) MPI and catheterization are more accurate but also more invasive and expensive. It appears that CPX may improve the diagnostic accuracy of exercise ECG. This review will address the potential utility of CPX in patients with suspected or confirmed myocardial ischemia.