Exercise Electrocardiography Research Articles

Comparative effectiveness of exercise electrocardiography versus exercise echocardiography in women presenting with suspected coronary artery disease: a randomized study.

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. 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. 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.

Teaching medical students the QT interval and its autonomous regulation in a practical ECG course in physiology

Background: The QT interval is a well established marker for ventricular repolarization. As the QT interval is inversely regulated with the heart rate, several correction formula are established to calculate corrected QT intervals (QT c ). In practical courses of physiology, medical students learn the correct measurement of the QT interval and its autonomous regulation. For this, students record and analyse ECGs under resting conditions and during/following a workout. However, little is known about teaching QT/QT c skills in students. In particular, it is not established whether untrained medical students can determine the length of the QT interval in rest and following an exercise with sufficient accuracy to allow discussion of its physiological regulation. Methods: A full cohort of 3rd year medical students (n=380) participated in a practical ECG course. In each course (20 students), ECGs of volunteers were recorded in small groups (2-4 students) under resting conditions and immediately following standardised physical exercise (squats and push-ups). Students calculated HR, QT intervals and QT c intervals using Bazett’s exponential correction. Automatically calculated QT intervals were retrieved from the ECG devices. Following the course, QT intervals of the same ECG passages were measured by experienced physiology teachers and expert clinical electrophysiologists. To compare effects of established QT c correction formulas, QT c was calculated for all retrieved intervals using Bazett, Framingham, Fridericia and Hodges. Data were analysed on the level of individual experiments and as pooled data of student groups. Results: In 117 experiments, students reported resting HRs of ~70 bpm and corresponding QT intervals of ~360 ms. Following exercise, students found an average increase of the HR by ~75% and a decrease of the QT interval by ~25%. Using pooled data sets of each course, the overall efficacy of the Bazett formula could well be demonstrated. Students HR data were highly concordant with the data generated by the automated ECG routines, the experienced physiologists and the clinical electrophysiologists. While average QT and QT c intervals were also comparable between the groups, the variance was substantially higher in students data than in the other groups, especially in the exercise ECGs. In the HR ranges generated in the course, QT correction by Fridericia and Framingham was more efficient than by Bazett and Hodges. Conclusions: Untrained students can determine QT intervals from ECGs recorded under resting conditions and following a workout with sufficient accuracy to demonstrate the autonomous regulation of this important (bio)marker on the level of individual data sets. Due to the high individual variance of the QT c , however, we recommend QT c correction based on data pooled within each student group to discuss the relevance of the QT correction formulas. The study was financed by institutional budget. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

PO-04-017 'LEFT' BROKEN AFTER EXERCISE: A CASE OF PAINFUL LBBB SYNDROME SUCCESSFULLY TREATED WITH LEFT BUNDLE BRANCH AREA PACING

The leading causes of new-onset left bundle branch block (LBBB) include coronary artery disease, hypertension, and cardiomyopathies. However, when the LBBB occurs in the absence of ischemia, in a rate-dependent manner, usually with exertion, it constitutes a painful left bundle branch block. Although there are multiple case reports of this entity, the mechanism, pathophysiology, and treatment are not well defined. We intend to raise awareness of this syndrome and highlight our unique treatment approach. NA A 57-year-old male presented to the cardiology clinic with exertional chest pain and palpitations. He underwent an exercise ECG test, surprisingly on stage 2 of Bruce protocol, at around a heart rate of 116 bpm; he started developing LBBB on every other beat. At a heart rate of 125 bpm, he developed persistent LBBB associated with similar symptoms, both of which persisted in the recovery phase (Figure 1). His Echocardiogram was normal. Invasive coronary angiography revealed normal coronaries. Previous case reports have shown that cardiac rehabilitation helps to delay the onset of LBBB to a higher heart rate; however, he opted for pacemaker implantation as he had severe exercise limitations. He underwent a biventricular-implantable pacemaker with right atrial, left bundle branch area, and coronary sinus (CS) left ventricular (LV) leads. The pacemaker was programmed DDD60 with a rate adaptive AV interval with a start rate of 80 bpm. This would enable the LBB area pacing above a heart rate of 80 bpm. Within one week of implantation, the patient had a complete resolution of his symptoms. A cardiopulmonary exercise test to assess VO2 with pacing programmed off and then on is scheduled as part of the follow-up. The symptoms of the painful LBBB syndrome can be quite severe, resulting in physical and psychological debilitation. Treatment with a physical exercise regimen has been successful as it delays the LBBB onset to a higher heart rate. However, the patient loses the benefit once they stop exercising. A definitive solution is a pacemaker; there are multiple case reports of His bundle and right ventricular pacing, which successfully treated this syndrome. In this case, we used a unique approach of pacing just the LBBB area; in addition, a CS LV lead was placed, which could be used for an earlier activation of the LV if the patient needs that in the future.

Incremental Value of Exercise ECG to Myocardial Perfusion Single-Photon Emission Computed Tomography for Prediction of Cardiac Events.

Background Both myocardial perfusion single-photon emission computed tomography (MPS) and exercise ECG (Ex-ECG) carry prognostic information in patients with stable chest pain. However, it is not fully understood if combining the findings of MPS and Ex-ECG improves risk prediction. Current guidelines no longer recommend Ex-ECG for diagnostic evaluation of chronic coronary syndrome, but Ex-ECG could still be of incremental prognostic importance. Methods and Results This study comprised 908 consecutive patients (age 63.3±9.4 years, 49% male) who performed MPS with Ex-ECG. Subjects were followed for 5 years. The end point was a composite of cardiovascular death, acute myocardial infarction, unstable angina, and unplanned percutaneous coronary intervention. National registry data and medical charts were used for end point allocation. Combining the findings of MPS and Ex-ECG resulted in concordant evidence of ischemia in 72 patients or absence of ischemia in 634 patients. Discordant results were found in 202 patients (MPS-/Ex-ECG+, n=126 and MPS+/Ex-ECG-, n=76). During follow-up, 95 events occurred. Annualized event rates significantly increased across groups (MPS-/Ex-ECG- =1.3%, MPS-/Ex-ECG+ =3.0%, MPS+/Ex-ECG- =5.1% and MPS+/Ex-ECG+ =8.0%). In multivariable analyses MPS was the strongest predictor regardless of Ex-ECG findings (MPS+/Ex-ECG-, hazard ratio [HR], 3.0, P=0.001 or MPS+/Ex-ECG+, HR,4.0, P<0.001). However, an abnormal Ex-ECG almost doubled the risk in subjects with normal MPS (MPS-/Ex-ECG+, HR, 1.9, P=0.04). Conclusions In patients with chronic coronary syndrome, combining the results from MPS and Ex-ECG led to improved risk prediction. Even though MPS is the stronger predictor, there is an incremental value of adding data from Ex-ECG to MPS, especially in patients with normal MPS.

Modern Aspects of Exercise Tolerance Assessment in Children with Post-COVID Syndrome, Pneumonia, and Obesity

An important and understudied problem is the state of health of children and adolescents who have experienced acute respiratory diseases or suffer from chronic diseases. Suffering from COVID-19 and post-COVID-19 syndrome, pneumonia are complex pathological conditions that significantly affect the functional capabilities of the child’s body and quality of life. Obesity, which is also an important medical and social problem, has no less impact on health. The purpose of the work is to summarize the data from the literature about the value of exercise tests in children with postcovid syndrome, after pneumonia of various etiologies, and obesity; modern aspects for assessing exercise tolerance. It is worth noting that nowadays screening programs for examining the health of children, aimed at prevention and early detection of pathological changes, play an important role. One of these methods of diagnosis, which makes it possible to determine and comprehensively analyze the body’s functional capabilities, is the assessment of exercise tolerance. The diagnostic value of analyzing the tolerance level lies in assessing the impact of various pathological conditions on the child’s health, and quality of life. The obtained results can be used to develop rehabilitation measures to eliminate the symptoms of acute diseases and improve the quality ofi fle. Tests with dosed physical exertion are used to assess exercise tolerance. The «gold standard» of the technique is cardiopulmonary exercise testing. However, world tolerance assessment guidelines include the use of other types of tests, such as office and field tests. The «gold standard» for assessing tolerance is the determination of the maximum oxygen consumption (VO2max), which characterizes the maximum amount of oxygen that is absorbed and used by the body during intense physical exertion involving a large possible part of the muscles. Also, during exercise tests, heart rate, blood pressure, and electrocardiogram recording are monitored, which creates significant diagnostic search opportunities for the pediatrician.

Relationship Between Caffeine Consumption and Young Athletes' Comorbidities, Exercise-Related Symptoms, and Baseline Electrocardiogram.

Caffeine consumption causes diverse physiologic effects that can affect athletes both positively and negatively. There is a lack of research investigating the long-term effects of caffeine intake on exercise and on overall cardiovascular health in young athletes. Certain characteristics such as age, body mass index (BMI), race, and medical diagnoses are associated with increased caffeine use, and there is a relationship between caffeine consumption and symptoms during exercise and cardiovascular abnormalities in young athletes. Cross-sectional study. Level 4. This study utilized the HeartBytes National Youth Cardiac Registry to collect data related to demographics, caffeine use, and physical examination and electrocardiogram (ECG) findings of 7425 12- to 20-year-olds (60.6% male, 39.4% female) who attended a Simon's Heart cardiac screening event between 2014 and 2021. Univariable and multivariable logistic regression models were used for analysis. Persons who consumed caffeine were more likely to have attention deficit hyperactivity disorder (ADHD) (adjusted odds ratio [aOR], 1.43; CI, 1.15-1.76]; P < 0.01) and more likely to have a BMI ≥30 kg/m2 (aOR, 1.69; CI, 1.27-2.25]; P < 0.01) compared with nondrinkers. After controlling for age, gender, race, and BMI, there were no significant differences in symptoms during exercise (aOR, 1.27; CI, 0.97-1.66; P = 0.08) or abnormal ECG findings (OR, 0.93; CI, 0.66-1.31; P = 0.70) between those who consume caffeine and those who do not. Caffeine consumption was associated with increased BMI and increased likelihood of having ADHD; however, caffeine use overall was not associated with increased risk of symptoms during exercise or ECG abnormalities. Whereas caffeine consumption overall did not increase risk of exercise-related symptoms, soda drinkers were at higher risk for symptoms during exercise, and coffee drinkers were at higher risk of syncope with exercise. Prospective studies with longitudinal follow-up and more specific outcomes data is the next step in qualifying the impact of caffeine on young athletes.

A novel approach for biometric recognition based on ECG feature vectors

In the field of biometrics, electrocardiogram (ECG) recognition has the advantages of being live, difficult to replicate, and easy to collect. However, most deep learning methods for biometric recognition use a fixed length of ECG beats and only identify ECGs from a fixed number of people. The fixed input length may lead to information loss and the model needs to be retrained when a new ECG is added to the database, which is inconvenient for real applications. In this paper, we propose a biometric recognition method based on an ECG feature vector that uses a pooling layer to accept variable-length beat signals. The method accepts new classes without requiring model retraining while achieving excellent recognition performance. We verified the robustness of the method in the ECG-ID database, the MITDB arrhythmia database, and a private USSTDB database consisting of the ECG records of 60 volunteers before and after exercise. In addition, this method has good recognition ability in cross-database tests. The proposed method reduces the gap in biometric identification of exercise ECGs and demonstrates robustness and good generalization.

Preoperative Stress Testing before Non-Cardiac Surgery.

The current guidelines from various medical societies provide a good summary of data regarding various preoperative exercise tests in patients prior to non-cardiac surgical interventions. However, there is no consensus among experts on the appropriateness of these methods for identifying risk groups for potential perioperative complications. A large volume of published studies describes the role of preoperative exercise stress testing impact in improving the prediction of potential cardiovascular (CV) risk in patients after non-cardiac surgery. Numerous stress tests are available in clinical practice, and the methods used and the best choice depends on the purpose of the study and the availability of equipment in the hospital. Traditionally, the value of exercise electrocardiography (ECG), or ECG stress test, has been based on the belief that it is beneficial for perioperative cardiac risk prediction. However, in the past two decades, the key role of this method has lost its importance due to the growing trend toward the use of imaging techniques. Moreover, in light of current trends, the six-minute walk test (6MWT) is a helpful tool in preoperative assessment and plays an important role in postoperative rehabilitation. Interestingly, the recent finding showed how 6MWT affects the risk of postoperative complications. Cardiopulmonary testing, as a dynamic clinical tool, determines the cardiorespiratory status of a patient. Various clinical indications for cardiopulmonary exercise testing include evaluation of therapy, stratification of risk factors, diagnosis of disease, and control of physical activity. Stress testing is one of the most practical ways of predicting perioperative risk and managing patients. This test is based on ischemia provoked by pharmacological agents or exercise. There is no established evidence of a significant advantage of pharmacological stress over exercise stress imaging in subjects who are capable enough to be physically active. All of these studies examined a stress test for induced myocardial ischemia. Currently, there are no data on the use of ischaemic stress tests, especially diastolic stress tests, in the assessment of perioperative risk before non-cardiac surgical interventions. We consider it promising and essential to continue research in this direction in patients with coronary heart disease and other categories of cardiac patients, in particular, comorbid and low-symptomatic individuals, before elective high-risk surgical interventions.

Early detection of myocardial ischemia in resting ECG: analysis by HHT

BackgroundExercise 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.MethodsElectrocardiographic 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.ResultsAfter 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.ConclusionsPatients 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.

Functional outcomes in post Covid-19 patients with persistent dyspnea: multidisciplinary approach

Background: Post-acute sequelae of SARS-CoV-2 (PASC) have emerged as a major health issue in patients who have previously been infected with Covid-19 virus. Purpose: we aimed at the assessment of functional outcomes in post Covid-19 patients with persistent dyspnea using a multidisciplinary approach including clinical assessment, laboratory investigations, exercise ECG, and different echo-Doppler modalities, including left atrial functions. Methods: The current observational randomized controlled study conducted on 60- patients one month after recovery from Covid-19 infection presented with persistent dyspnea compared to 30 healthy volunteers. All participants were subjected to evaluation of dyspnea by different scores, laboratory investigations, stress ECG, and echo-Doppler examination to measure LV dimensions, volumes, systolic and diastolic functions by M-mode, 2D, and tissue Doppler imaging in addition to 2-D speckle tacking LA strain. Results: Post Covid-19 patients had persistent elevation of inflammatory markers, low functional capacity (evidenced by a higher NYHA class, m MRC score, PCFS scale) and decreased METs by stress ECG compared to control group. Post Covid-19 patients showed LV diastolic dysfunction and impairment of 2D-STE LA functions compared to control group. We found negative correlations between LA strain with NYHA class, mMRC scale, LAVI, ESR and CRP; meanwhile, there were significant positive correlations between LA strain with exercise duration and METs. Conclusion: post Covid patients presented with persistent dyspnea demonstrated low functional capacity evidenced by different scores and stress ECG. Moreover, patients with post Covid syndrome showed elevated inflammatory biomarkers, LV diastolic dysfunction in addition to impaired LA strain functions. Impairment of LA strain was closely correlated to different functional scores, inflammatory biomarkers, exercise duration, and METs suggesting that these could to be the possible etiologies for the persistence of post Covid symptoms.

Positive Stress Electrocardiography in Patients With Non-obstructive Coronary Disease.

Introduction The episodes of myocardial ischemia in patients with non-obstructive coronary disease are extremely variable in provoking factors and presentation. Purpose We investigated the significance of coronary blood flow velocity and epicardial diameter as correlates of a positive electrocardiographic exercise stress test (ExECG) in hospitalized patients with unstable angina and non-obstructive coronary artery disease. Methods The study was a single-center cohort retrospective. ExECG was performed and analyzed in a group of 79 patients with non-obstructive coronary disease (coronary stenoses < 50%). Thirty-one percent of the patients (n=25) were diagnosed with slow coronary flow phenomenon, SCFP; 40.5% (n=32) - patients with hypertensive disease, left ventricular hypertrophy (LVH), and slow epicardialflow; 27.8% (n=22) with hypertension, left ventricular hypertrophy and normal coronaryflow. The patients were hospitalized in University Hospital "Alexandrovska," Sofia in the period 2006-2008. Results The frequency of positive ExECG is increased as a trend was associated with smaller epicardial diameters and pronounced delay in epicardial coronaryflow.In the subgroup with SCFP, the risk for a positive ExECG test was determined by slower coronary flow (36.5±7.7 frames vs. 30.3±4.4 frames, p=0.044) and borderline significant by epicardial lumen diameters (3.3±0.8 mm vs. 4.1±1.0 mm, p=0.051) and greater myocardial mass (92.8±12.6 g/m2 vs. 82.9±8.6 g/m2, p=0.054). In cases of left ventricular hypertrophy, which included both patients with the normal and slow epicardialflow, there were no statistically significant correlates of an abnormal exercise stress ECG test. Conclusions In patients with non-obstructive coronary atherosclerosis and predominantly slow epicardial coronary flow, the provoking of ischemia at an electrocardiographic exercise stress test is associated with the lower epicardial flow velocity at rest and with the smaller epicardial diameter. In SCFP, the risk for an abnormal stress test is determined by slower coronary flow, smaller epicardial lumen diameter, and greater myocardial mass.The presence and size of the plaque burden are not associated with a greater risk of a positive ExECG in these patients.

Diagnostic evaluation of unexplained ventricular tachyarrhythmias in younger adults.

The diagnostic work-up for cardiac arrest from ventricular tachyarrhythmias occurring in younger adults and structurally normal hearts is variable and often incomplete. We reviewed records for all recipients of a secondary prevention implantable cardiac defibrillator (ICD) younger than 60 years at a single quaternary referral hospital from 2010 to 2021. Patients with unexplained ventricular arrhythmias (UVA) were identified as those with no structural heart disease on echocardiogram, no obstructive coronary disease, and no clear diagnostic features on ECG. We specifically evaluated the adoption rate of five modalities of "second-line"cardiac investigations: cardiac magnetic resonance imaging (CMR), exercise ECG, flecainide challenge, electrophysiology study (EPS), and genetic testing. We also evaluated patterns of antiarrhythmic drug therapy and device-detected arrhythmias and compared them with secondary prevention ICD recipients with a clear etiology found on initial assessment. One hundred and two recipients of a secondary prevention ICD under the age of 60 were analyzed. Thirty-nine patients (38.2%) were identified with UVA and were compared with the remaining 63 patients with VA of clear etiology (61.8%). UVA patients were younger (35.6 ± 13.0vs. 46.0 ± 8.6 years, p < .001) and were more often female (48.7% vs. 28.6%, p = .04). CMR was performed in 32 patients with UVA (82.1%), whereas flecainide challenge, stress ECG, genetic testing, and EPS were only performed in a minority of patients. Overall, the use of a second-line investigation suggested an etiology in 17 patients with UVA (43.5%). Compared to patients with VA of clear etiology, UVA patients had lower rates of antiarrhythmic drug prescription (64.1% vs. 88.9%, p = .003) and had a higher rate of device-delivered tachy-therapies (30.8% vs. 14.3%, p = .045). In this real-world analysis of patients with UVA, the diagnostic work-up is often incomplete. While CMR was increasingly utilized at our institution, investigations for channelopathies and genetic causes appear to be underutilized. Implementation of a systematic protocol for work-up of these patients requires further study.

Ectopic Supraventricular Rhythms during Exercise Electrocardiography

Three cases of the new appearance of ectopic supraventricular rhythms during exercise electrocardiography are presented. Transient decrease in the rate of the sinoatrial node or transient increase in the rate of subsidiary pacemaker are responsible. Electrocardiographic criteria for diagnosing the site of origin of supraventricular ectopic foci are discussed. The diagnostic, and prognostic significance of such a finding is not known.

Multi‐modal machine learning based on electrocardiogram data for prediction of patients with ischemic heart disease

Electrocardiogram is a non-invasive method to diagnose patients with cardiovascular diseases. Electrocardiogram analysis methods using deep neural networks have been widely used in recent years and are becoming more efficient and accurate than traditional machine learning methods. Exercise electrocardiogram is useful in the diagnosis of ischemic heart disease, but the study of long-term ischemic heart disease prediction based on exercise electrocardiogram is still limited. To investigate the early predictive value of exercise electrocardiogram in addition to basic physiological data in incident ischemic heart disease in a random general population sample followed from 40 to 69 years of age, a multi-modal fusion model is designed to predict ischemic heart disease based on machine learning methods. With the deep feature extractor and multi-modal feature fusion module, the proposed model performance is better than the traditional expert feature based methods and only deep neural networks. This implies that this proposed model may be improved in a contemporary era of ischemic heart disease prevention with the gradually declining incidence of ischemic heart disease.

Significance of Rate-Pressure Product and Duke Treadmill Score in Predicting Disease Severity in Patients with Coronary Artery Disease: A Cross-sectional Study

Introduction: Exercise electrocardiography is a well-established and cost-effective investigation for evaluating Coronary Artery Disease (CAD). The Rate-pressure Product (RPP), which is the product of maximal Systolic Blood Pressure (SBP) and peak Heart Rate (HR) during exercise, is a widely accepted parameter reflecting cardiac work and evaluating ventricular function. The use of Duke Treadmill Score (DTS) improves the diagnostic accuracy of exercise-induced ST-segment depression and has been observed to provide independent prognostic information. It has been shown that DTS provides information about the complexity of coronary artery lesions assessed by invasive coronary artery testing. Aim: To determine the significance of RPP and DTS in predicting the severity and complexity of angiographic lesions in patients with Stable Ischemic Heart Disease (SIHD) and a positive Treadmill Test (TMT). Materials and Methods: This study involved 100 consecutive patients with a positive TMT but no prior history of Acute Coronary Syndrome (ACS) who underwent coronary angiography at Government Medical College, Kottayam, Kerala, India, between March 2018 and March 2019 after obtaining ethical clearance from the Institutional Review Board. The DTS and RPP were calculated for these patients. All patients then underwent coronary angiography, and their SYNTAX scores were calculated. Correlation analysis was performed to assess the relationship between DTS, RPP, and SYNTAX score using Spearman's correlation coefficient. The Kruskall-Wallis test was used to compare risk factors among groups. Results: A total of 100 patients were evaluated, ranging in age from 40 to 74 years with an average age of 57 years. The average SYNTAX score was 15, ranging from 2 to 56. The average Duke TMT score was -5.2, ranging from 6 to -22. There was a significant negative correlation between DTS and angiographic severity determined by SYNTAX score (r=-0.702, p=0.001). The average RPP was 22174, ranging from 14000 to 37620. The study showed a significant negative correlation between RPP and SYNTAX score (r=-0.201, p=0.04). Diabetic patients had a significantly higher SYNTAX score compared to non-diabetics (r=-0.602, p=0.013). Additionally, a significant negative correlation was observed between the Metabolic Equivalents (METs) attained, duration of exercise, and the SYNTAX score. Conclusion: DTS and RPP derived from the exercise treadmill test have a significant negative correlation with the severity and complexity of CAD as determined by the SYNTAX score in coronary angiography.

Italian return to play protocol after COVID-19 in young competitive and professional athletes: diagnostic yield and cost-benefit analysis.

Return to play (RTP) protocols have been proposed to early detect cardiovascular involvement due to COVID-19 and reduce the risk of sports-related sudden cardiac death. However, uncertainties remain about the true prevalence of COVID-19 myopericarditis, the arrhythmic risk and the cost of this protocol. We collected data from 217 competitive and professional athletes of both genders who underwent RTP protocol (clinical history, resting and exercise ECG, and echocardiography). Holter monitoring and/or cardiac magnetic resonance (CMR) were performed in case of abnormalities. In 107 athletes, the RTP data were compared with those of preparticipation evaluation (PPE) performed prior to COVID-19 infection. Out of 217 consecutive athletes evaluated with the RTP protocol, 7 underwent CMR: among these we found alterations compatible with myopericarditis in 3 (1.4%), with a cost per person of € 223.93 and a cost per diagnosis of € 16,197.53. Of the 107 athletes previously evaluated with PPE, 4 underwent RMC: we made a final diagnosis of myocarditis in 1 athlete (0.9%), whereas another athlete (0.9%) showed moderate pericardial effusion. The clinical presentation of both these athletes was characterized by the presence of ventricular arrhythmias newly detected during RTP. Compared to PPE, during RTP higher values were observed for shortness of breath, weight, heart rate and corrected QT interval, whereas lower values for sinus bradycardia and the E/A ratio of mitral flow. The prevalence of myopericarditis was similar to that reported in previous cross-sectional and case-control studies. The availability of data recorded before COVID-19 was important in the evaluation of athletes with arrhythmias. The RTP protocol has proven to be less cost effective than normal PPE.

Heart Rate Response Patterns during Different Stages of Stress Phase of Exercise Electrocardiography Using Bruce Protocol in Normal Persons

There is no literature about different patterns of heart rate response during different stages of exercise stress electrocardiography using Bruce protocol in normal persons. We studied seventy five individuals after strictly excluding various conditions that could affect exercise capacity or heart rate response. Only ten persons had nearly linear progressive increase in heart rate. Other individuals had variable increase during different stages of stress. We observed eleven different types of responses. Our study shows that every individual has an intrinsic maximal heart rate that can be attained during exercise. Magnitude of the increase in heart rate during a particular stage of stress is influenced by the magnitude of increase in heart rate and percentage of age predicted maximal heart rate attained by the individual prior to that stage. It is also influenced by the relative activation of the sympathetic and the parasympathetic systems during and prior to a particular stage.

Screen-printed fabric electrode for electrocardiogram monitoring on commercial textiles

Due to the low-cost fabrication, printing electronics on flexible substrates shows great potential in robotics, wearable healthcare, and persistent human-machine interfaces. Noninvasive dry-electrodes for electrocardiography (ECG) monitoring are an important technique for detecting early arrhythmias. This article describes a screen printing method for fabricating textile ECG electrodes. The biocompatible carbon ink served as the active electrochemical layer, while the silver paste acted as the conductive path, respectively. The measured results showed that the textile electrode had similar ECG signal monitoring performance compared to commercially available Ag/AgCl electrodes under conditions where the subjects were walking, stationary, and jogging. And the pre-made textile electrodes can be easily connected to the sports bra for monitoring daily exercise ECG. This study demonstrated the feasibility of utilizing textile electrodes for applications in the wearable healthcare industry.

Noninvasive predictors of coronary slow flow phenomenon in patients presenting with chronic coronary syndrome

Background: Patients with coronary slow flow phenomenon (CSFP) exhibit the following characteristics: Predominantly middle-aged males, the majority have mixed pattern angina, persistent chest pain sensations after therapy, and many have had repeated invasive and non-invasive examinations. Objectives: Our study aimed to determine the base of non-invasive predictors of coronary slow flow phenomenon in patients presenting with chronic coronary syndrome. Patients and Methods: This a case-control study included 100 participants of suspected coronary artery disease were divided into two groups matched in age and sex group I: 50 patients with primary (CSFP) and group II: 50 patients with normal coronary angiography. Each patient was undergoing to demographic data taking, physical investigation, good hydration, restrict fasting hours requested for coronary angiography, 12 lead-ECGs were obtained for each patient at rest, laboratory parameters, coronary angiography, Treadmill exercise ECG, Transthoracic echocardiography to assess the thickness of the LV wall, the interior dimensions of the LV, the LV EF using M-mood method and the aortic propagation velocity. Results: Male Sex and CCSA class 3 were significantly decreased in group I compared to group II and male sex,DM, smoker and CCSA class 4 were substantially increase in group I compared to group II (p

Exercise-induced myocardial ischemia presenting as exercise intolerance after carbon monoxide intoxication and smoke inhalation Injury: case report

BackgroundCarbon monoxide intoxication and smoke inhalation injury can lead to severe disorders, and the current literature has elaborated on the importance of major cardiopulmonary impairment. Exercise intolerance has seldom been discussed, particular in patient with low cardiovascular risk.Case presentationTwo young male fire survivors who presented with exercise intolerance after CO intoxication and smoke inhalation injury. Both received bronchodilator and glucocorticoid therapy, high-flow oxygen therapy, and hyperbaric oxygen therapy for airway edema and CO intoxication during acute care. Serum carboxyhemoglobin levels improved after treatment (8.2–3.9% in Case A and 14.8–0.8% in Case B). However, subjective exercise intolerance was noted after discharge. Cardiopulmonary exercise testing revealed exercise-induced myocardial ischemia during peak exercise (significant ST-segment depression on exercise electrocardiogram). They were instructed to exercise with precaution by setting the intensity threshold according to the ischemic threshold. Their symptoms improved, and no cardiopulmonary events were reported in the 6-month follow-up.ConclusionThe present case report raised the attention that exercise intolerance after carbon monoxide intoxication and smoke inhalation injury in low cardiovascular risk population may be underestimated. Cardiopulmonary exercise testing help physician to discover exercise-induced myocardial ischemia and set up the cardiac rehabilitation program accordingly.