Non-diagnostic ECG Research Articles

Are medical history data fit for risk stratification of patients with chest pain in emergency care? Comparing data collected from patients using computerized history taking with data documented by physicians in the electronic health record in the CLEOS-CPDS prospective cohort study.

In acute chest pain management, risk stratification tools, including medical history, are recommended. We compared the fraction of patients with sufficient clinical data obtained using computerized history taking software (CHT) versus physician-acquired medical history to calculate established risk scores and assessed the patient-by-patient agreement between these 2 ways of obtaining medical history information. This was a prospective cohort study of clinically stable patients aged ≥ 18 years presenting to the emergency department (ED) at Danderyd University Hospital (Stockholm, Sweden) in 2017-2019 with acute chest pain and non-diagnostic ECG and serum markers. Medical histories were self-reported using CHT on a tablet. Observations on discrete variables in the risk scores were extracted from electronic health records (EHR) and the CHT database. The patient-by-patient agreement was described by Cohen's kappa statistics. Of the total 1000 patients included (mean age 55.3 ± 17.4 years; 54% women), HEART score, EDACS, and T-MACS could be calculated in 75%, 74%, and 83% by CHT and in 31%, 7%, and 25% by EHR, respectively. The agreement between CHT and EHR was slight to moderate (kappa 0.19-0.70) for chest pain characteristics and moderate to almost perfect (kappa 0.55-0.91) for risk factors. CHT can acquire and document data for chest pain risk stratification in most ED patients using established risk scores, achieving this goal for a substantially larger number of patients, as compared to EHR data. The agreement between CHT and physician-acquired history taking is high for traditional risk factors and lower for chest pain characteristics. ClinicalTrials.gov NCT03439449.

Supermarket/hypermarket opportunistic screening for atrial fibrillation (SHOPS-AF) using sensors embedded in the handles of supermarket trolleys: A feasibility study

BackgroundAtrial fibrillation (AF) increases the risk of death, stroke, heart failure, cognitive decline, and healthcare costs but is often asymptomatic and undiagnosed. There is currently no national screening programme for AF. The advent of validated hand-held devices allows AF to be detected in non-healthcare settings, enabling screening to be undertaken within the community. Method and ResultsIn this novel observational study, we embedded a MyDiagnostick single lead ECG sensor into the handles of shopping trolleys in four supermarkets in the Northwest of England: 2155 participants were recruited. Of these, 231 participants either activated the sensor or had an irregular pulse, suggesting AF. Some participants agreed to use the sensor but refused to provide their contact details, or consent to pulse assessment. In addition, some data were missing, resulting in 203 participants being included in the final analyses. Fifty-nine participants (mean age 73.6 years, 43% female) were confirmed or suspected of having AF; 20 were known to have AF and 39 were previously undiagnosed. There was no evidence of AF in 115 participants and the remaining 46 recordings were non-diagnostic, mainly due to artefact. Men and older participants were significantly more likely to have newly diagnosed AF. Due to the number of non-diagnostic ECGs (n=46), we completed three levels of analyses, excluding all non-diagnostic ECGs, assuming all non-diagnostic ECGs were masking AF, and assuming all non-diagnostic ECGs were not AF. Based on the results of the three analyses, the sensor's sensitivity (95% CI) ranged from 0.70 - 0.93; specificity from 0.15 - 0.97; positive predictive values (PPV) and negative predictive values (NPV) ranged from 0.24 - 0.56 and 0.55-1.00, respectively. These values should be interpreted with caution, as the ideal reference standard on 1934 participants was imperfect. ConclusionThe study demonstrates that the public will engage with AF screening undertaken as part of their daily routines using hand-held devices. Sensors can play a key role in identifying asymptomatic patients in this way, but the technology must be further developed to reduce the quantity of non-diagnostic ECGs.

An intelligent computer-aided diagnosis method for paroxysmal atrial fibrillation patients with nondiagnostic ECG signals

Classification of ECG signals plays an important role in the field of medical diagnosis. Despite that much progress has been made in ECG classification in recent years, most of them focus on single-lead cardiac feature extraction. In this paper, we propose a new classification method based on twelve-lead surface ECG signal by fusing improved hand-crafted ECG features and deep learning classifiers for paroxysmal atrial fibrillation (PAF) detection. Three-dimensional dominated components are extracted without ECG signal segmentation operations, and continuous wavelet transform (CWT) is adopted for time–frequency representation to reflect essential characteristics of multi-resolution frequency domain at different scales. This kind of time–frequency representation has high discriminative power to detect PAF even before pathologic changes in surface twelve-lead ECG signals. Five pre-trained deep neural networks models are used to perform transfer learning and feature fusion. ECG signals are finally classified by using a feature fusion method based on multiple deep networks.

Arrhythmias induced by dextrose-insulin challenge test in nondiagnostic Brugada ECG patterns.

Dynamic ECG changes in Brugada syndrome (BrS) are influenced by several factors, may not be apparent, and can be unmasked by a drug test. Four of six patients with nondiagnostic Brugada ECG index patterns underwent a dextrose-insulin challenge test that resulted in J-ST segment elevation and triggered arrhythmias. Insulin action may be due in part to an outward shift in the K+ current at the end of action potential phase 1 and the dispersion of repolarization, leading to local re-entry with arrhythmogenicity. This effect is likely a phenomenon-specific to BrS.

Simplified Geleijnse score for identifying chest pain features associated with coronary ischemia

BackgroundThe Geleijnse score, which was proposed to assess for coronary ischemia, has practical limitations. ObjectivesOur aim was to design and evaluate a simplified version of the Geleijnse score. MethodsWe enrolled patients with suspected coronary heart disease but negative troponin T or absence of enzymatic curve, and a non-diagnostic 12-lead ECG. The initial study was performed in a retrospective derivation cohort and the results were subsequently validated in a prospective cohort. ResultsFrom 109 patients included in the derivation cohort, 33 (30.3%) received a diagnosis of coronary heart disease. Chest pain with both arms radiation (OR 3.54), severe intensity (OR 2.41), improvement by nitroglycerin (OR 1.61), associated dyspnea (OR 1.97) and prior exertional angina history (OR 2.91) were independently associated with an ischemic origin on multivariate logistic regression analysis. ROC curves comparison demonstrated both the original and simplified scores presented modest predictive ability with significant difference when analyzed using dichotomous cut-offs (0.647 [simplified] vs. 0.544 [original], p = 0.042) but not as a continuous variable (0.670 [simplified] vs. 0.621 [original], p = 0.396). In 305 patients from the validation cohort, the simplified score presented extensively increased predictive accuracy than the Geleijnse, in the continuous (c-indexes = 0.735 vs. 0.685, p = 0.040) and the dichotomic (c-indexes = 0.682 vs. 0.514, p<0.001) forms. ConclusionsA simplified version of the Geleijnse score, including some routine clinical manifestations associated with coronary heart disease, presented significantly better predictive ability compared to the original score.

Prediction of significant coronary artery disease in acute chest pain without infarction in emergency department: MAPAC Cardio-PreTest model.

Acute nontraumatic chest pain is a frequent reaso n for consultation in emergency departments and represents a diagnostic challenge. The objective is to estimate the risk of significant coronary artery disease (CAD) in patients with cardiogenic acute chest pain for whom the diagnosis of infarction was ruled out in the emergency department with a nondiagnostic ECG and negative high-sensitivity troponins. We prospectively recruited 1625 patients from emergency departments of seven Spanish hospitals. The outcome was presence of significant CAD determined by presence of ischaemia in functional tests or more than 70% stenosis in imaging tests. In this study, we developed a predictive model and evaluated its performance and clinical utility. The prevalence of significant CAD was 14% [227/1625; 95% confidence interval (CI), 12-16]. MAPAC Cardio-PreTest model included seven predictors: age, sex, smoking, history of hypertension, family history of CAD, history of hyperuricaemia, and type of chest pain. The optimism-adjusted model discrimination was C-statistic 0.654 (95% CI, 0.618-0.693). Calibration plot showed good agreement between the predicted and observed risks, and calibration slope was 0.880 (95% CI, 0.731-1.108) and calibration-in-the-large -0.001 (95% CI, -0.141 to 0.132). The model increased net benefit and improved risk classification over the recommended approach by the European Society of Cardiology [Net Reclassification Index (NRI) of events = 5.3%, NRI of nonevents = 7.0%]. MAPAC Cardio-PreTest model is an online prediction tool to estimate the individualised probability of significant CAD in patients with acute chest pain without a diagnosis of infarction in emergency department. The model was more useful than the current alternatives in helping patients and clinicians make individually tailored choices about the intensity of monitoring or additional coronary tests.

Computerized history taking improves HEART score determination in acute chest pain patients

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Robert Bosch Stiftung (Stuttgart, Germany) Region Stockholm (ALF project; Stockholm, Sweden) Introduction Chest pain is a common chief complaint in emergency departments (EDs). The Acute Cardiovascular Care Association recommends the use of History, ECG, Age, Risk factors, and Troponin (HEART) score for risk stratification. In hectic and overcrowded EDs computerized history taking (CHT) is one structured way for collecting the components of HEART score, which include medical history (H- and R-variables). Purpose To determine the proportion of acute chest pain patients where CHT can be used to calculate HEART score, and what interrater reliability the included variables have with physician acquired medical history. Methods Prospective cohort study with acute chest pain patients self-reporting medical histories using a CHT program (Clinical Expert Operating System, CLEOS) on a tablet. CLEOS, with &amp;gt;17,000 decision nodes, mimics a physician interview and tailors each interview continuously depending on previous answers. Clinically stable women and men aged &amp;gt;18 years with a chief complaint of chest pain and non-diagnostic ECG or serum markers for acute coronary syndrome were enrolled. Patients unable to carry out a CHT interview (e.g., severe impaired vision or confusion) were excluded. As recommended in regional guidelines a modified HEART score using the traditional classification of anginal symptoms, i.e. 1) central chest pain, 2) provoked by physical exertion and/or emotional stress, and 3) relieved by rest and/or nitrates, and traditional risk factors was used (see Table 1). Observations to each discrete H- and R-variable and medical history data were extracted from electronic health records (EHR) and the CHT database by the research staff. Cohen’s kappa statistics and interpretation according to Landis &amp; Koch was used to describe the interrater reliability. Results A total of 1,000 consecutive patients were enrolled in one tertiary university hospital ED during 2017–2019 (mean age 55±17 years; 54% women), comparable to the general chest pain population (mean age 58±19 years; 50% women). A complete HEART score could be calculated in 60% of patients (H-variable 91%; R-variable 60%). Registered observations from EHR and CHT and interrater reliability data are presented in Table 1. Interrater reliability for the H-variable (classical anginal symptoms) was slight to moderate (kappa 0.19-0.44) and the R-variable (traditional risk factors) was moderate to almost perfect (kappa 0.56-0.88). Conclusions HEART score could be calculated in a majority of acute chest pain patients by the use of CHT. Interrater reliability was high for traditional risk factors but low to moderate for classical anginal symptoms. Our ongoing studies assess whether CHT combined with a risk score such as HEART score in an acute setting can be useful for improved risk stratification and, more important, to improve clinical outcomes.

Unshielded magnetocardiography contributes to non-invasively rule-out ischemic heart disease in patients with chest pain of uncertain origin

Abstract Background Out of millions of patients (pts) screened every year for chest pain in emergency departments (EDs) only 10% to 20% are affected by an acute coronary syndrome (ACS) or angina due to ischemic heart disease (IHD). Unless ECG recording and serum markers are clearly positive, most of them must undergo complete clinical workout to exclude IHD prior to discharge. Moreover, since even effort-ECG and echocardiography don't exhaustively rule-out IHD, second-level exams are frequently needed, enhancing hospitalization time and related costs. Magnetocardiography (MCG) is increasingly reported as a sensitive, non-invasive, radiation-free method with high negative predictive value (PV) to rule out IHD. Purpose Retrospective cohort study to evaluate the reliability likelihood of unshielded MCG (uMCG) as a tool for rapid rule-out of IHD. Method Rest uMCG data of 263 patients (pts), all chest-pain free at the moment of MCG scan, were retrospectively analyzed. uMCG was recorded with a 36-channel SQUID system (intrinsic sensitivity 30 fT/√Hz, above 1Hz), for 90 seconds. With proprietary software, 13 MCG parameters were automatically calculated from T-wave magnetic field (T-MF): 5 parameters quantifying the dynamics of the MF extrema and eight, obtained from inverse solution with the equivalent magnetic dipole (EMD) model, quantifying the spatial dynamics of the T-wave effective magnetic vector (T-EMV). Pts were stratified as follows: – Group A, chest pain pts, with IHD confirmed by subsequent SPECT and coronary angiography (mean age 66±11 years, 36.7% female); – Group B, chest pain pts, with IHD excluded by subsequent SPECT or coronary angiography (mean age 59±10 years, 28.8% female); – Group C, healthy control subjects (mean age 25±7 years, 48.6% female). Only 60 pts in each group were randomly selected for the analysis. Non-parametric Kruskal-Wallis tests were used to compare the 13 MCG predictors among groups. Linear discriminant analysis was employed to assess likelihood ratios (LHR) and PVs, considering a mean IHD prevalence of 13% (range 10–20%) in chest-pain pts. Results Positive LHR was 9, while the negative LHR was 0.3, resulting in a helpful reduction of the pre-test probability of IHD. Whereas positive PV ranges from 51 to 70%, hardly confirming IHD diagnosis, negative PV ranges from 92 to 96%, giving confidence for a safe IHD rule-out. Conclusions Automatic analysis of T-MF and of T-EMV dynamics from rest MCG provided impressive negative LHR and PV values that, if confirmed in prospective multicenter trials, would rank MCG as a useful tool for quick and early triage of pts with acute chest pain and still non-diagnostic ECG and enzyme patterns, to rule-out those whose symptoms are of non-ischemic origin. Interestingly, a similar high negative PV has been recently reported using MCG QRS predictors. Thus, even better results could be expected by combining algorithms for automatic assessment of both T-wave and QRS predictors. Funding Acknowledgement Type of funding sources: None.

Angina due to coronary artery spasm (variant angina): diagnosis and intervention strategies

ABSTRACT Introduction Since Prinzmetal first described a ‘variant’ form of angina pectoris, with predominantly resting episodes of pain and cyclic severity variations, it has gradually become apparent that this clinical presentation is caused by episodes of coronary artery spasm (CAS) involving focal or diffuse changes in large and/or small coronary arteries in the presence or absence of ‘fixed’ coronary artery stenoses. However, most clinicians have only limited understanding of this group of disorders. Areas covered We examine the clinical presentation of CAS, associated pathologies outside the coronary vasculature, impediments to making the diagnosis, provocative diagnostic tests, available and emerging treatments, and the current understanding of pathogenesis. Expert opinion CAS is often debilitating and substantially under-diagnosed and occur mainly in women. Many patients presenting with CAS crises have non-diagnostic ECGs and normal serum troponin concentrations, but CAS can be suspected on the basis of history and association with migraine, Raynaud’s phenomenon and Kounis syndrome. Definitive diagnosis requires provocative testing at coronary angiography. Treatment still centers around the use of calcium antagonists, but with greater understanding of pathogenesis, new management options are emerging.

UNVEILING THE VILLAIN: AN INTRIGUING CASE OF DIAGNOSING BRUGADA SYNDROME

TOPIC: Cardiovascular Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Brugada syndrome is a rare condition that is associated with an increased risk of ventricular tachyarrhythmias and sudden cardiac death. The typical electrocardiographic features of Brugada syndrome are variable and are known to be revealed by several precipitants such as drugs, and febrile illnesses. The following case describes the incidental ECG findings of Brugada pattern in a patient who presented with dizziness, shortness of breath and recently diagnosed deep vein thrombosis in her left leg. CASE PRESENTATION: A 63-year-old female with a history of breast cancer on tamoxifen, and recently diagnosed deep vein thrombosis on rivaroxaban presented to the emergency department with shortness of breath. Chest x-ray revealed no radiographic abnormality. EKG was significant for coving ST segment elevations on V1 and V2 consistent with Brugada type 1. She underwent emergent left heart catheterization which revealed normal coronaries. CT chest with contrast demonstrated the presence of a right subsegmental pulmonary embolism. Echocardiography revealed a left ventricular EF of 70% and no valvular pathology. Her shortness of breath improved. She was counselled on risks, given a list of medications to avoid and advised to treat fevers. She declined to have genetic testing. DISCUSSION: The typical EKG features of Brugada syndrome are variable and are known to be revealed by several precipitants. The patient was not aware of any family history of Brugada syndrome. She stated that during her knee replacement surgeries, she had a witnessed vasovagal syncopal episode with no VF or VT reported on telemetry. CONCLUSIONS: This case highlights the presentation of Brugada syndrome in a patient precipitated by pulmonary embolism. It is recommended that such patients undergo genetic testing. Current recommendations are to place an ICD in those who survived cardiac arrest. Pharmacological treatment with quinidine is also an option. Treatment of asymptomatic patients is more complicated, and personalized risk-stratification is essential to providing the right management for these patients. REFERENCE #1: Antzelevitch C, Brugada P, Borggrefe M, et al. Brugada syndrome: report of the second consensus conference: endorsed by the Heart Rhythm Society and the European Heart Rhythm Association. Circulation 2005;111:659–70 REFERENCE #2: Veltmann C, Schimpf R, Echternach C, et al. A prospective study on spontaneous fluctuations between diagnostic and non-diagnostic ECGs in Brugada syndrome: implications for correct phenotyping and risk stratification. Eur Heart J 2006;272544–52 REFERENCE #3: Lamelas P, Labadet C, Spernanzoni F, et al. Brugada electrocardiographic pattern induced by fever. World J Cardiol 2012;4:84–6 DISCLOSURES: No relevant relationships by HANAD BASHIR, source=Web Response No relevant relationships by Jeff Courson, source=Web Response No relevant relationships by NICOLE LAO, source=Web Response No relevant relationships by Gauranga Mahalwar, source=Web Response

Detection of Significant Coronary Artery Disease by Two Dimensional Speckle Tracking Echocardiography in Patients with Suspected ACS and Non-Diagnostic ECG and Cardiac Biomarkers

Detection of Significant Coronary Artery Disease by Two Dimensional Speckle Tracking Echocardiography in Patients with Suspected ACS and Non-Diagnostic ECG and Cardiac Biomarkers

Abstract 13628: Absence of Coronary Artery Calcium in Ruling Out Obstructive Cad on Coronary Computed Tomography Angiography (ccta) Among Patients With Stable and Acute Chest Pain: A Systematic Review

Introduction: Coronary computed tomography angiography (CCTA) is a class IIA recommendation in low-intermediate risk patients with suspected acute coronary syndrome (ACS) and a normal or nondiagnostic cardiac biomarker and ECG. However, there is little consensus on whether absence of coronary artery calcium (CAC) can safely identify patients with stable and acute chest pain (CP) who can avoid more advanced downstream testing. In this study, we conducted a systematic analysis investigating utility of CAC zero in ruling out obstructive coronary artery disease (CAD) among patients with stable and acute CP undergoing coronary CT angiography (CCTA). Methods: We searched online databases (PubMed, MEDLINE) for original research articles published between 2005 and 2020 examining the relationship between CAC and significant stenosis on CCTA (defined as &gt;50% coronary luminal narrowing) among patients with stable and acute chest pain. Results: A systematic review of published articles revealed 18 studies including 27,719 patients with stable CP and 12 studies including 7,184 patients with acute CP undergoing simultaneous CCTA and CAC scoring. Overall, 12,664 (45%, 95% CI: 39%-50%) patients with stable CP and 4,327 (56%, 95% CI: 48%-64%) patients with acute CP had CAC zero. The pooled prevalence of obstructive CAD among those with CAC=0 was 3% (95% CI: 2%-4%) among stable CP patients and 2% (95% CI: 1%-3%) among acute CP patients. The negative predictive values for any CAC ruling out obstructive disease were 97% (95% CI: 96-98%) and 98% (95% CI: 96-100%), respectively (Figure). Conclusions: Among over 34,000 patients with stable and acute CP patients undergoing CCTA, the absence of CAC was associated with a very low likelihood of obstructive CAD. These findings support role of CAC zero in a value-based healthcare delivery model as a gatekeeper for more advanced testing.

External validation of a clinical decision rule to identify patients at low risk for acute coronary syndrome who do not need objective coronary artery disease testing

Abstract Background Rapid high-sensitivity cardiac troponin (hs-cTn) based algorithms have substantially improved the early rule-out of acute myocardial infarction (AMI) and thereby facilitated the selection of patients eligible for outpatient management. However, it remains unclear, which patients after rule-out of AMI should still undergo objective anatomic or functional cardiac testing for the detection of relevant coronary artery disease. A pilot study has derived a clinical decision rule for the selection of patients who do not need objective anatomic or functional cardiac testing for coronary artery disease (“No Objective Testing” (NOT) rule). Purpose To externally validate the performance of the NOT-rule in a multicentre study. Methods Patients presenting to the ED with symptoms suggestive of an acute coronary syndrome (ACS) were enrolled in a large prospective international multicentre study at 12 study sites in five European countries. Two independent cardiologists centrally adjudicated the final diagnosis using all clinical data including cardiac imaging and at least 90-day follow-up. The NOT-rule is applied in patients, in whom a 2h accelerated diagnostic protocol (using hs-cTnI concentrations at 0h/2h and ECG data) has ruled-out AMI and based on clinical variables. In brief, the first rule is a weighted score derived from independent predictors of ACS that classifies patients as low-risk if they score ≤4 points. The second rule was simplified and ruled patients out if they were younger than 50 years, had no history of an AMI or known CAD, and no prescribed nitrates. The third rule equals the second except nitrate use was omitted. Primary objective was the safety and efficacy of the NOT-rules for rule-out of major adverse cardiac events (MACE) including AMI, unstable angina pectoris, urgent or emergency revascularisation or cardiovascular death at 30-days of follow-up. Secondary objective was the safety and efficacy for rule-out of MACE at 2-years. Results Out of 3188 enrolled patients, 2162 (68%) had hs-cTnI concentrations at 0h and 2h below the 99th centile as well as a non-diagnostic ECG and were therefore eligible for the analysis. MACE at 30-days occurred in 302 (14%) patients. The second and third rule offered highest safety and efficacy for rule-out of MACE at 30-days. Both identified 492 (23%) patients at low-risk with a sensitivity of 99.7% (95% CI 98.2–99.9%) and a negative predictive value (NPV) of 99.8% (95% CI 98.6–99.9%). One MACE was missed within 30-days (revascularisation of a one-vessel CAD). Sensitivity 98.9% (95% CI 97.1–99.7%) and NPV 99.2% (95% CI 97.8–99.7) were also very high for 1-year MACE, as well as 2-year MACE 98.4% (95% CI 96.5–99.4%) and 98.4% (95% CI 96.5–99.3%), respectively. Conclusions The NOT rules proved to be a safe tool that identifies nearly one-fourth of patients at very low risk for MACE, who may not need objective anatomic or functional cardiac testing for coronary artery disease. Performance of NOT rules Funding Acknowledgement Type of funding source: Other. Main funding source(s): Swiss National Science Foundation, the Swiss Heart Foundation, the KTI, the European Union, the Stiftung für kardiovaskuläre Forschung Basel, the University of Basel, the University Hospital Basel

Predictive factors of a prolonged total ischemic time in patients presenting with ST-segment elevation myocardial infarction

Abstract Introduction Total ischemic time (TIT), the time from symptom onset to therapeutic reperfusion of infarcted myocardium is a key factor in the treatment of patients with ST-segment elevation myocardial infarction (STEMI). The identification of the predictive factors of a prolonged TIT will allow design specific strategies to optimize this time and improve the quality of care of these patients. Our objective was to evaluate independent factors predicting prolonged TIT. Methods We performed a prospective observational study, with consecutive inclusion of all patients presenting within 24 hours of symptom onset of STEMI (n=546), transferred to our center for primary percutaneous coronary intervention (pPCI). Results The median TIT was 190 (137–281) minutes. No significant differences were found according to the year of study. In the univariate analysis, age showed a slight trend (p=0.05); for each year that is increased, the TTI increases 1.3 minutes. Women had higher TII than men [219 (145–332) vs. 187 (133–270) minutes; p=0.02]. No statistically significant differences were found in relation to the presence of cardiovascular risk factors. Patients treated during non-working hours had shorter TIT than those treated during working hours [179 (130–252) vs. 202 (142–307) minutes; p=0.03]. The distance to a 24h-PCI hospital was an independent predictive factor. Those patients whose first medical contact (FMC) was in a non-PCI-capable hospital or in a clinic showed the highest TIT [226 (147–336) and 205 (146–304) minutes, respectively; p&amp;lt;0.001]. Patients with initial non-diagnostic ECG presented a significantly longer TIT (p&amp;lt;0.001) than patients correctly diagnosed since the beginning, with a median difference of 188 minutes. A trend was observed for the Killip-Kimball classification variable (p=0.07). Patients with previous infarction had shorter TIT compared to those who have never had it (p=0.02). In the multivariate binary logistic regression analysis, the variables: initial non-diagnostic ECG, FMC (in a non-PCI-capable hospital or clinic) and the distance to 24h-PCI hospital (&amp;gt;90 km) were independent predictive factors of a TIT &amp;gt;180 minutes. An initial non-diagnostic or misinterpreted ECG sextuples the risk of a prolonged TIT. Conclusions In our area, the total ischemic time is determined by a non-diagnostic or misinterpreted EKG, the first medical contact and the distance to a 24h-PCI hospital. Funding Acknowledgement Type of funding source: None

Implications of Abnormal Exercise Electrocardiography With Normal Stress Echocardiography

Patients with abnormal (positive) exercise electrocardiography, but normal stress echocardiography (+ECG/-Echo) are commonly encountered in clinical practice; however, the prognostic significance of this discordant result is unclear. To determine whether patients with +ECG/-Echo have a higher rate of adverse clinical events and a poorer prognosis than patients with negative exercise ECG and normal stress Echo imaging (-ECG/-Echo). Between January 1, 2000, and February 28, 2014, a total of 47 944 consecutive patients without known coronary artery disease who underwent exercise stress Echo at Duke University Medical Center were evaluated for inclusion in this observational cohort study. Data analysis was conducted from January 1, 2000, to December 31, 2016. Patients were categorized as having -ECG/-Echo, +ECG/-Echo, or +Echo (-ECG/+Echo and +ECG/+Echo). The primary outcome was a composite end point of death, myocardial infarction, hospitalization for unstable angina, and coronary revascularization. Secondary outcomes included individual adverse events and downstream testing. After excluding submaximal tests and nondiagnostic ECG or stress imaging results, 15 077 patients (mean [SD] age, 52 [13] years; 6228 [41.3%] men) were classified by stress test results. Of these, 12 893 patients (85.5%) had -ECG/-Echo, 1286 patients (8.5%) had +ECG/-Echo, and 898 patients (6.0%) had +Echo. Through a median follow-up of 7.3 (interquartile range, 4.4-10.0) years, the composite end point occurred in 794 patients with -ECG/-Echo (8.5%), 142 patients with +ECG/-Echo (14.6%), and 297 patients with +Echo (37.4%). Death occurred in 425 patients with -ECG/-Echo (4.8%), 50 patients with +ECG/-Echo (5.9%), and 70 patients with +Echo (11.2%). Myocardial infarction occurred in 195 patients with -ECG/-Echo (2.2%), 31 patients with +ECG/-Echo (3.6%), and 59 patients with +Echo (8.7%). The addition of stress ECG findings to clinical and exercise data yielded incremental prognostic value. Patients with -ECG/-Echo imaging results had the least downstream testing (2.3%), followed by +ECG/-Echo (12.8%), and +Echo (33.6%) (P < .001). The presence of +ECG results with normal stress Echo imaging may identify a population of patients who are at slightly increased risk for adverse cardiac events, which was not previously recognized. Further study is needed to determine whether these patients will benefit from intensification of medical management.

Methemoglobinemia due to local anesthesia: a rare cause of cyanosis and chest pain after placement of implantable cardioverter defibrillator.

Although methemoglobinemia is rare in adulthood, it may have fatal consequences if unnoticed. We planned to implant an implantable cardioverter defibrillator ICD in a 50-year-old male patient for primary prevention. Following sterile draping, prilocaine 5 mg/kg (400 mg) was injected subcutaneously for local anesthesia. We injected an additional dose of 200 mg due to pain during subclavian vein puncture. A DDD-R ICD was placed successfully within approximately 40 minutes. The patient complained of sudden chest pain and dyspnea 15 minutes after bed rest and was transferred to the coronary care unit due to cyanosis and deterioration of general status. Physical examination revealed blood pressure of 110/80 mmHg, pulse rate of 110 bpm, and otherwise unremarkable signs. Peripheral oxygen saturation was determined as 83% by pulse oximeter. Possible pneumothorax and cardiac perforation were excluded by emergency chest radiograph and echocardiography. Blood gas analyses was performed to assess for methemoglobinemia, which revealed pH 7.41, pCO2 40 mmHg, oxygen saturation 98.2%, and methemoglobin 7.9% that peaked to 12.3%. Methylene blue (1%) was slowly injected over 10 minutes at a dose of 1 mg/kg. Cyanosis waned and methemoglobin values decreased to 4.1%, 2.1%, and 1.1% at 2, 8, and 16 hours following the administration, respectively. The patient was safely discharged 2 days after implantation of pacemaker. Methemoglobinemia should be considered in cases presenting with cyanosis, non-diagnostic ECG, and a discrepancy in oxygen saturation between pulse oximetry and blood gas analyses.

Value of the coronary artery disease consortium rule in patients with acute chest pain and negative troponins referred for exercise stress testing.

To assess the value of the pretest probability (PTP) of coronary artery disease (CAD) for predicting stress testing results and coronary events in patients with acute chest pain and negative troponins. A total of 3527 patients without a history of CAD referred to our chest pain unit with suspected acute coronary syndromes, nondiagnostic ECGs, and negative troponin levels underwent exercise stress testing. PTP was estimated with the CAD consortium prediction rule, and was categorized as low (<15%), low-intermediate (15-65%), intermediate-high (66-85%), and high (>85%). The endpoints were the presence of signs of inducible myocardial ischemia on stress testing and the occurrence of coronary events within 6 months. The probability of exercise-induced myocardial ischemia was 2.6, 12.6, 42.9, and 82.1% in patients with low, low-intermediate, intermediate-high, and high PTP, respectively (Ptrend<0.001). The cumulative rate of coronary events within 6 months was also significantly lower in patients with low PTP of CAD (0.8%) than in those with low-intermediate (6.9%), intermediate-high (32.5%), or high PTP (66.7%) (Ptrend<0.001). Per 10% increment in PTP of CAD, the adjusted odds ratios for inducible myocardial ischemia and coronary events within 6 months were, respectively, 1.71 (95% confidence interval: 1.61-1.85) and 1.87 (95% confidence interval: 1.74-2.01). PTP was associated strongly with the likelihood of exercise-induced myocardial ischemia and coronary events in patients with suspected acute coronary syndromes and negative troponins. The yield of stress testing in the subset of patients with low PTP was very low.

Risk stratifying chest pain patients in the emergency department using HEART, GRACE and TIMI scores, with a single contemporary troponin result, to predict major adverse cardiac events

BackgroundThe majority of patients presenting to the ED with cardiac sounding chest pain have a non-diagnostic ECG and the problem of differentiating those suffering an acute coronary syndrome from those...

Efficacy and safety of dextrose-insulin in unmasking non-diagnostic Brugada ECG patterns

BackgroundTypical diagnostic, coved-type 1, Brugada ECG patterns fluctuate spontaneously over time with a high proportion of non-diagnostic ECG patterns. Insulin modulates ion transport mechanisms and causes hyperpolarization of the resting potential. We report our experience with unmasking J-ST changes in response to a dextrose–insulin test. MethodsNine patients, mean age 40.5±19.4years (range: 15–65years), presented initially with a non-diagnostic ECG pattern, which was suggestive of Brugada syndrome (group I). They were compared with 10 patients with normal ECG patterns (group II). Participants received an infusion of 50g of 50% dextrose, followed by 10IU of intravenous regular insulin. Positive changes were defined by conversion to a diagnostic ECG pattern. ResultsThe dextrose–insulin test was positive in six of seven (85.7%) patients (kappa 0.79, p=0.02) that was confirmed with a pharmacologic test (kappa 1, p=0.003). One had an inconclusive test, and two with a negative test had an early repolarization ECG pattern. All subjects in group II had a negative test (p<0.01). The maximum changes of the J-ST segment were observed 41.3±31.4minutes (range 3–90minutes) after dextrose–insulin infusion. One patient had monomorphic ventricular bigeminy without spontaneous or induced ventricular fibrillation. ConclusionChanges in J-ST segment in the Brugada syndrome are influenced by glucose–insulin, and this report reproduces and supports the efficacy and safety of this metabolic test in the differential diagnosis of patients with non-diagnostic ECG patterns.

Validation of the new Vancouver Chest Pain Rule in Asian chest pain patients presenting at the emergency department.

The new Vancouver Chest Pain (VCP) Rule recommends early discharge for chest pain patients who are at low risk of developing acute coronary syndrome (ACS), and thus can be discharged within 2 hours of arrival at the emergency department (ED). This study aimed to assess the performance of the new VCP Rule for Asian patients presenting with chest pain at the ED. This prospective cohort study involved patients attended to at the ED of a large urban centre. Patients of at least 25 years old, presenting with stable chest pain and a non-diagnostic ECG, and with no history of active coronary artery disease were included in the study. The main outcome measures were cardiac events, angioplasty, or coronary artery bypass within 30 days of enrolment. The study included 1690 patients from 27 August 2000 to 1 May 2002, with 661 patients fulfilling the VCP criteria. Of those for early discharge, 24 had cardiac events and 13 had angioplasty or bypass at 30 days, compared to 91 and 41, respectively, for those unsuitable for discharge. This gave the rule a sensitivity of 78.1% for cardiac events, including angioplasty and bypass. Specificity was 41.0%, and negative predictive value (NPV) was 94.4%. We found the new VCP Rule to have moderate sensitivity and poor specificity for adverse cardiac events in our population. With an NPV of less than 100%, this means that a small proportion of patients sent home with early discharge would still have adverse cardiac events.