Ischemic Electrocardiogram Research Articles

Association of Hypertension and Ischaemic ECG Changes in Type II Diabetes Mellitus

Background: Type 2 diabetes mellitus (T2DM) is one of the most common metabolic disorders to the current generation. It usually leads to multi-system­ic complications such as cardiovascular diseases, proteinuria, micro albumin­uria, retinopathy, hypertension, ischaemic changes and chronic kidney disease. These complications increase the morbidity and mortality of patients. The pro­longed hyperglycemia leads to vascular damage. It causes insufficient blood flow to the cardiac muscles which may cause myocardial or cardiac ischaemia. The aim of this study was to find out the prevalence of hypertension and isch­aemic ECG changes in T2DM patients attending Kathmandu Medical College.
 Methods: Total 360 type 2 diabetic patients were included. Blood pressure was measured and electrocardiogram (ECG) was recorded by 12 leads ECG. Statistical analysis was done using SPSS version 16. p<0.05 was considered to be statistically significant.
 Results: The mean age of the patients was 66.88 ± 1.52 years, age ranging from 40 – 95 years. In this study 168 patients (46.66%) had systolic hyperten­sion, 204 patients (56.67%) had diastolic hypertension and 126 (35%) had both systolic and diastolic hypertension. About 103 (28.61%) showed ECG changes in hypertensive patients. Only 4 (1.11%) non- hypertensive had ECG changes. This study showed statistically significant relation of hypertension and isch­aemic ECG changes in type 2 diabetes mellitus cases with p- value 0.03.
 Conclusions: There is a high prevalence of hypertension among T2DM pa­tients. In these patients, there is a statistically significant association between hypertension and ischaemic ECG changes.

Association between Ischemic Electrocardiographic Changes during Acetylcholine Provocation Test and Long-Term Clinical Outcomes in Patients with Vasospastic Angina

Objectives Intracoronary injection of acetylcholine (Ach) has been shown to induce significant coronary artery spasm (CAS) in patients with vasospastic angina. Clinical significance and angiographic characteristics of patients with ischemic electrocardiogram (ECG) changes during the Ach provocation test are not clarified yet. Methods A total 4,418 consecutive patients underwent coronary angiography with Ach provocation tests from 2004 to 2012 were enrolled. Ischemic ECG changes were defined as transient ST-segment depression or elevation ( > 1 mm) and T inversion with/without chest pain. Finally, a total 2,293 patients (28.5% of total subjects) proven CAS were enrolled for this study. Results A total 119 patients (5.2%) showed ECG changes during Ach provocation tests. The baseline clinical and procedural characteristics are well balanced between the two groups. Ischemic ECG change group showed more frequent chest pain, higher incidence of baseline spasm, severe vasospasm, multi-vessel involvement, and more diffuse spasm ( > 30 mm) than those without ischemic ECG changes. At 5 years, the incidences of death, major adverse cardiac events (MACE) and major adverse cardiac and cerebral events (MACCE) were higher in the ischemic ECG change group despite of optimal medical therapy. Conclusions The patients with ischemic ECG changes during Ach provocation tests were associated with more frequent chest pain, baseline spasm, diffuse, severe and multi-vessel spasm than patients without ischemic ECG changes. At 5-years, the incidences of death, MACE and MACCE were higher in the ischemic ECG change group, suggesting more intensive medical therapy with close clinical follow up will be required.

Sex Disparities in First Medical Contact of Patients with Suspected Acute Coronary Syndrome Using Telemedicine Technology.

Background:Reducing door-to-balloon time may not reduce mortality, but reducing the time from symptom onset to first medical contact (FMC) may alone improve patient outcomes. The purpose of this study was to focus on analyzing sex differences in FMC call delay and its trend over the decades in patients with suspected acute coronary syndrome (ACS).Methods:Large private telemedicine data in patients with suspected ACS were used to investigate time delay in contacting a telemedicine call center. We identified 24,592 calls to a primary call center of patients with anginal symptoms and first electrocardiogram (ECG), using mobile 12-lead ECG devices. For the purpose of the current analysis, we included the first call of 14,420 patients for whom demographic, clinical ECG data were available.Results:First mobile ECG changes included suspected S-T Segment (ST) elevation in 2,220 (16%) cases, ST depression in 3,143 (22%) cases, or both in 685 (5%) patients. There were 6,721 (47%) calls to the center within less than 1 h of symptom onset. Chest pain, dyspnea, heart rate, male sex, absence of diabetes mellitus, early time period of the study, and ischemic ST segment changes on the first ECG were all independently associated with the increased likelihood of contacting the center within less than 1 h of symptom onset to FMC (p < 0.01 for all).Conclusions:Both chest pain and ischemic ECG changes were sex dependent for early medical contact, as such factors were significant among men (p = 0.001 and p = 0.024, respectively), but not among women (p = 0.024). The later time period of the study was associated with a shorter time delay among women more than that of men (p = 0.014). Women with prehospital chest pain or ischemic ST segment changes tend to seek medical help later than men. Temporal trends show attenuation of this sex disparity, with more women presenting earlier in the last decade.

Development of a New Index of Body Shape to Detect Ischemic Electrocardiogram Abnormalities

【目的】IHD（虚血性心疾患）関連の心電図異常を見出す能力が高い，侵襲性のない新しい体格指数を作成することを目的とした。

Protective Effect and Metabonomics Research of "Biao-Ben Acupoint Combination" Electroacupuncture in Chronic Myocardial Ischemia Model Rats

To observe the effect of electroacupuncture (EA) on ischemic electrocardiogram (ECG), histopathological changes and serum metabolite profile in chronic myocardial ischemia (CMI) rats, so as to reveal its mechanisms underlying protecting ischemic myocardium. A total of 45 male Wistar rats were randomly divided into normal control, CMI model and EA groups, with 15 rats being in each group. The rats in the control group received subcutaneous injection of 0.9% normal saline (5 mg•mg－1•d－1, for 7 days), and those in the model and EA groups received subcutaneous injection of isopropylarterenol hydrochloride (5 mg•mg－1•d－1, for 7 days) to establish CMI model. EA (2 Hz/100 Hz, 1 mA) was applied to bilateral "Zusanli" (ST 36), "Guanyuan" (CV 4) and "Neiguan" (PC 6) for 10 min, once daily for 21 days. The ECG-ST segment of the standard limb lead II was used for evaluating the severity of myocardial ischemia, and the histopathological changes of myocardium were observed under microscope after H．E. staining. The profile of serum metabolites was analyzed by nuclear magnetic resonance mass spectrometry combined with principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) in 21 rats (n＝7 in each group)．. After modeling, the amplitude of ECG-ST was significantly increased in comparison with the normal control group (P<0.01), suggesting a successful establishment of CMI model. H．E. stain showed an apparent injury of the myocardial tissue as interstitial edema, vasodilatation and hemorrhage, infiltration of inflammatory cells, unclear veins, and increased intercellular space, etc. with irregularly arranged myocardial cells being dissolved, ruptured and necrotic, and with obvious edema, blurred shape, uneven staining, karyopyknosis, and glass-like lesions. After EA intervention, the amplitude of ECG-ST in the EA group was evidently lower than that of the model group (P<0.01), and the severity of the myocardial injury was relatively milder relevant to the model group, suggesting an alleviation of the injured myocardium. In the PLS-DA score plot, the normal control group and the EA group outline were close to each other, and Glucose, Lactate, Creatine, Acetate, 3-Hydroybutyrate might be the potential metabolic differential biomarkers (VIP > 1). The PLS-DA analysis revealed deviations in 51 differential biomarkers in serum，among which, Glucose, Lactate, Creatine, Acetate and 3-Hydroybutyrate may contribute to the effect of EA in improving CMI. EA stimulation of acupoints can ameliorate ischemic myocardial injury in CMI rats, which may be related to its effect in regulating serum sugar, lipid metabolism and energy metabolism.

Risk Factor Modeling for Cardiovascular Disease in Type 1 Diabetes in the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study: A Comparison With the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study (DCCT/EDIC).

In a recent Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study report, mean HbA1c was the strongest predictor of cardiovascular disease (CVD) after age. In DCCT/EDIC, mean diabetes duration was 6 years (median 4) at baseline and those with high blood pressure or cholesterol were excluded. We now replicate these analyses in the Pittsburgh Epidemiology of Diabetes Complications (EDC) prospective cohort study of childhood-onset (at <17 years of age) type 1 diabetes, with similar age (mean 27 years in both studies) but longer diabetes duration (mean 19 years and median 18 years) and no CVD risk factor exclusion at baseline. CVD incidence (CVD death, myocardial infarction (MI), stroke, revascularization, angina, or ischemic electrocardiogram) was associated with diabetes duration, most recent albumin excretion rate (AER), updated mean triglycerides, baseline hypertension, baseline LDL cholesterol, and most recent HbA1c Major atherosclerotic cardiovascular events (CVD death, MI, or stroke) were associated with diabetes duration, most recent AER, baseline systolic blood pressure, baseline smoking, and updated mean HbA1c Compared with findings in DCCT/EDIC, traditional risk factors similarly predicted CVD; however AER predominates in EDC and HbA1c in DCCT/EDIC. Thus, the relative impact of HbA1c and kidney disease in type 1 diabetes varies according to diabetes duration.

Diagnostic accuracy of prehospital electrocardiograms interpreted remotely by emergency physicians in myocardial infarction patients

BackgroundPrehospital 12‑lead electrocardiogram (ECG) is the most widely used screening tool for recognition of ST-segment elevation myocardial infarction (STEMI). However, prehospital diagnosis of STEMI based solely on ECGs can be challenging. ObjectivesTo evaluate the ability of emergency department (ED) physicians to accurately interpret prehospital 12‑lead ECGs from a remote location. MethodsAll suspected prehospital STEMI patients who were transported by EMS and underwent angiography between 2006 and 2014 were included. We reviewed prehospital ECGs and grouped them based on: 1) presence or absence of a culprit artery lesion following angiography; and 2) whether they met the 3rd Universal Definition of Myocardial Infarction. We also described characteristics of ECGs that were misinterpreted by ED physicians. ResultsA total of 625 suspected STEMI cases were reviewed. Following angiography, 94% (590/625) of patients were found having a culprit artery lesion, while 6% (35/625) did not. Among these 35 patients, 24 had ECGs that mimicked STEMI criteria and 9 had non-ischemic signs. Upon ECG reinterpretation, 92% (577/625) had standard STEMI criteria while 8% (48/625) did not. Among these 48 patients, 35 had ischemic signs ECGs and 13 did not. Characteristics of misinterpreted ECGs included pericarditis, early repolarization, STE > 1 mm (1‑lead only), and negative T-wave. ConclusionsRemote interpretation of prehospital 12‑lead ECGs by ED physicians was a useful diagnostic tool in this EMS system. Even if the rate of ECG misinterpretation is low, there is still room for ED physicians operating from a remote location to improve their ability to accurately diagnose STEMI patients.

Received care compared to ADP-guided care of patients admitted to hospital with chest pain of possible cardiac origin.

PurposeTo assess the extent to which accelerated diagnostic protocols (ADPs), compared to traditional care, identify patients presenting to emergency departments (EDs) with chest pain who are at low cardiac risk and eligible for early ED discharge.Patients and methodsRetrospective study of 290 patients admitted to hospital for further evaluation of chest pain following negative ED workup (no acute ischemic electrocardiogram [ECG] changes or elevation of initial serum troponin assay). Demographic data, serial ECG and troponin results, Thrombolysis in Myocardial Infarction (TIMI) score, cardiac investigations, and outcomes (confirmed acute coronary syndrome [ACS] at discharge and major adverse cardiac events [MACEs]) over 6 months of follow-up were analyzed. A validated ADP (ADAPT-ADP) was retrospectively applied to the cohort, and processes and outcomes of ADP-guided care were compared with those of care actually received.ResultsPatients had mean (±SD) TIMI score of 1.8 (±1.7); six (2.0%) patients were diagnosed with ACS at discharge. At 6 months, one patient (0.3%) re-presented with ACS and two (0.6%) died of non-coronary causes. The ADAPT-ADP defined 97 (33.4%) patients as being at low risk and eligible for early ED discharge, but who instead incurred mean hospital stay of 1.5 days, with 40.2% in telemetry beds, and 21.6% subject to non-invasive testing with only one positive result for coronary artery disease. None had a discharge diagnosis of ACS or developed MACE at 6 months.ConclusionCompared to traditional care, application of the ADAPT-ADP would have allowed one-third of chest pain patients with initially negative investigations in ED to have been safely discharged from ED.

Outcome of all-comers with STEMI based on the grade of ischemia in the presenting ECG

BackgroundGrade 3 ischemia (G3I) in the 12‑lead electrocardiogram (ECG) predicts poor outcome in patients with ST-elevation myocardial infarction (STEMI). The outcome of G3I in “real-life” patient cohorts is unclear. MethodsThe aim of the study was to establish the prognostic significance of grade 2 ischemia (G2I), G3I and the STEMI patients excluded from ischemia grading (No grade of ischemia, NG) in a real-life patient population. We assessed in-hospital, 30-day and 1-year mortality as well as other endpoints. ResultsThe NG patients had more comorbidities and longer treatment delays than the two other groups. Short-term and 1-year mortality were highest in patients with NG and lowest in patients with G2I. Maximum troponin level was highest in G3I, followed by NG and G2I. In logistic regression multivariable analysis, NG was independently associated with 1-year mortality. ConclusionsNG predicted poor outcome in STEMI patients. G2I predicted relatively favorable outcome.

A Risk Assessment Score and Initial High-sensitivity Troponin Combine to Identify Low Risk of Acute Myocardial Infarction in the Emergency Department.

Early discharge of patients with presentations triggering assessment for possible acute coronary syndrome (ACS) is safe when clinical assessment indicates low risk, biomarkers are negative, and electrocardiograms (ECGs) are nonischemic. We hypothesized that the Emergency Department Assessment of Chest Pain Score (EDACS) combined with a single measurement of high-sensitivity cardiac troponin (hs-cTn) could allow early discharge of a clinically meaningful proportion of patients. We pooled data from four patient cohorts from New Zealand and Australia presenting to an emergency department with symptoms suggestive of ACS. The primary outcome was major adverse cardiac events (MACE) within 30 days of presentation. In patients with a nonischemic ECG we evaluated the sensitivity for MACE and percentage low risk of every combination of high-sensitivity cardiac troponinT (hs-cTnT) concentration and high-sensitivity cardiac troponinI (hs-cTnI) concentration with EDACS. We used a standard smoothing technique on the probability density function for hs-cTn and EDACS and applied bootstrapping to determine the optimal threshold combinations, namely, the combination that maximized the percentage low risk with ≥98.5% sensitivity for MACE. From 2,536 patients, 2,258 presented without an ischemic ECG of whom 272 (12.1%) had a MACE within 30 days. The optimal threshold for hs-cTnI was 7 ng/L combined with an EDACS threshold of 16 (36.8% patients low risk). The optimal thresholds for hs-cTnT were 8ng/L combined with an EDACS threshold of 15 (30.2% patients low risk). Single measurements of both hs-cTnI and hs-cTnT at presentation combined with EDACS to identify over 30% of patients as low risk and therefore eligible for safe early discharge after only one blood draw.

High-Sensitivity Cardiac Troponin T Improves the Diagnosis of Perioperative MI

The diagnosis of myocardial infarction (MI) after noncardiac surgery has traditionally relied on using relatively insensitive contemporary cardiac troponin (cTn) assays. We hypothesized that using a recently introduced novel high-sensitivity cTnT (hscTnT) assay would increase the detection rate of perioperative MI. In this ancillary study of the Vitamins in Nitrous Oxide trial, readjudicated incidence rates of myocardial injury (new isolated cTn elevation) and MI were compared when diagnosed by contemporary cTnI versus hscTnT. We probed various relative (eg, >50%) or absolute (eg, +5 ng/L) hscTnT change metrics. Inclusion criteria for this ancillary study were the presence of a baseline and at least 1 postoperative hscTnT value. Among 605 patients, 70 patients (12%) had electrocardiogram changes consistent with myocardial ischemia; 82 patients (14%) had myocardial injury diagnosed by contemporary cTnI, 31 (5.1%) of which had an adjudicated MI. After readjudication, 67 patients (11%) were diagnosed with MI when using hscTnT, a 2-fold increase. Incidence rates of postoperative myocardial injury ranged from 12% (n = 73) to 65% (n = 393) depending on the hscTnT metric used. Incidence rates of MI using various hscTnT change metrics and the presence of ischemic electrocardiogram changes, but without event adjudication, ranged from 3.6% (n = 22) to 12% (n = 74), a >3-fold difference. New postoperative hscTnT elevation, either by absolute or relative hscTnT change metric, was associated with an up to 5-fold increase in 6-month mortality. The use of hscTnT compared to contemporary cTnI increases the detection rate of perioperative MI by a factor of 2. Using different absolute or relative hscTnT change metrics may lead to under- or overdiagnosis of perioperative MI.

Correlation between electrocardiographic changes and coronary findings in patients with acute myocardial infarction and single-vessel disease.

Correlation of ST-segment elevation on the 12-lead electrocardiogram (ECG) with the expected affected coronary territory is established in patients with ST-elevation myocardial infarction (STEMI). In patients with non-ST-elevation myocardial infarction (NSTEMI), correlation of ischemic ECG abnormalities with the affected coronary territory has not been well-established. We sought to investigate the correlation of electrocardiographic abnormalities with the location of 1-vessel obstructive coronary artery disease (CAD) in patients with both STEMI and NSTEMI. In this retrospective study, the charts of all patients referred for coronary angiography in 2012 were reviewed. Patients with a single obstructive coronary artery plus angina-equivalent symptoms and an elevated cardiac troponin I was included. Available ECGs were interpreted by an experienced cardiologist (WSA) blinded to the result of angiography. Patients with complete bundle branch block or ventricular pacing were excluded. Ischemic ECG changes were correlated to a coronary territory based on predefined criteria. Of 131 included patients (mean age 64±13 years; 74% male), 29 had STEMI and 102 had NSTEMI. Eleven of 11 patients (100%) with anterior STEMI had left anterior descending artery (LAD) obstructive CAD. Of 18 patients with inferior STEMI, 14 (78%) had right coronary artery (RCA) obstructive CAD, 3 (17%) had left circumflex artery (LCX) artery obstructive CAD, and 1 (5%) had LAD obstructive CAD. Of 102 NSTEMI patients, 53 (52%) had definite ECG ischemic abnormalities. Of 31 patients with anterior definite ECG ischemic abnormalities, 30 (97%) had LAD obstructive CAD, and 1 (3%) had RCA obstructive CAD. Of 22 patients with inferior definite ECG ischemic abnormalities, 14 (64%) had RCA obstructive CAD, 5 (23%) had LCX obstructive CAD, and 3 (14%) had LAD obstructive CAD. Patients with anterior STEMI had LAD obstructive CAD. Patients with inferior STEMI were highly likely to have RCA or LCX obstructive CAD. Only half of NSTEMI patients had definite ischemic ECG abnormalities. When present, anterior ischemic ECG changes in patients with single vessel CAD with NSTEMI were predictive of LAD obstructive CAD.

Relation of Coronary Flow Reserve to Other Findings on Positron Emission Tomography Myocardial Perfusion Imaging and Left Heart Catheterization in Patients With End-stage Renal Disease Being Evaluated for Kidney Transplant

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD) and often goes undetected. Abnormal coronary flow reserve (CFR), which predicts increased risk of cardiac death, may be present in patients with ESRD without other evidence of coronary artery disease (CAD). We prospectively studied 131 patients who had rest and dipyridamole pharmacologic stress N13-ammonia positron emission tomography myocardial perfusion imaging (PET MPI) for kidney transplant evaluation. Thirty-four patients also had left heart catheterization. Abnormal PET MPI was defined as qualitative ischemia or infarct, stress electrocardiogram ischemia, or transient ischemic dilation. CFR was calculated as the ratio of stress to rest coronary blood flow. Global CFR < 2 was defined as abnormal. Of 131 patients who had PET MPI (66% male, 55.6 ± 12.1 years), 30% (39 of 131) had abnormal PET MPI and 59% (77 of 131) had abnormal CFR. In a subset of 34 patients who had left heart catheterization (66% male, 61.0 ± 12.1 years), 68% (23 of 34) had abnormal CFR on PET MPI, and 68% (23 of 34) had ≥70% obstruction on left heart catheterization. Abnormal CFR was not significantly associated with abnormal PET MPI (p = 0.13) or obstructive CAD on left heart catheterization (p = 0.26). In conclusion, in the first prospective study of PET MPI in patients with ESRD, abnormal CFR is highly prevalent and is independent of abnormal findings on PET MPI or obstructive CAD on left heart catheterization.

Riesgo de infarto de miocardio en pacientes críticos mayores de 65 años

Introducción. La enfermedad cardiovascular es la de mayor morbimortalidad en el mundo. El comportamiento de la enfermedad cardiovascular en la población añosa es poco conocida. Objetivo. Determinar el riesgo de infarto de miocardio en pacientes críticos mayores de 65 años. Diseño. Estudio observacional transversal durante el periodo 2014-2015. Lugar. Hospital II Vitarte EsSalud, Lima, Perú. Participantes. Pacientes críticos mayores de 65 años. Métodos. Se recogió los datos de historias clínicas de emergencia de 140 pacientes críticos mayores de 65 años. Se analizó la edad, sexo, antecedentes, prioridad de atención. Se detalló la relación entre las alteraciones electrocardiográficas y valor positivo de troponina. Se calculó la razón de prevalencia y el OR de prevalencia. Principales medidas de resultados. Relación entre las alteraciones electrocardiográficas y valor positivo de troponina. Resultados. Los resultados de las pruebas de troponina en varones y mujeres, mayores al valor superior de referencia, representaron el 50 y 66%, respectivamente, tanto al ingreso al servicio de emergencia como en el control obtenido entre 6 y 12 horas después. Alrededor de 70% de pacientes con alteraciones de tipo isquémicas en el electrocardiograma (ECG) tuvieron troponina positiva para necrosis miocárdica. La prevalencia (RP) y el OR de prevalencia (ORP) para ECG isquémico y troponina positiva al ingreso fue 1,779 (IC95%: 1,215 a 2,604), y 3,7 (IC95%: 1,662 a 8,44), respectivamente. Para el ECG y troponina positiva control, la RP fue 1,969 (IC95%: 1,345 a 2,884) y el ORP fue 5,101 (IC95%: 2,187 a 11,9). Conclusiones. Se encontró un mayor riesgo de infarto de miocardio en pacientes críticos mayores de 65 años que presentaron alteraciones electrocardiográficas de tipo isquémicas durante su permanencia en el servicio de emergencia.

Spontaneous Coronary Artery Dissection Causing ST-Elevation Myocardial Infarction in a Young Adult: A Case Report

Introduction: ST-elevation myocardial infarction (STEMI) rarely occurs among patients 18 to 34 years old. Spontaneous coronary artery dissection (SCAD) is a rare cause of STEMI that is frequently described among patients in peripartum period. SCAD has a high mortality rate when not recognized and treated immediately. We present a case of SCAD presenting as STEMI in a nineteen-year-old non pregnant patient. Case: A nineteen-year-old female with chronic kidney disease complained of sudden-onset substernal chest pain. Physical examination showed blood pressure of 140/90 mmHg, heart rate of 112 beats per minute, with findings of of bibasilar rales, pedal edema and cold and clammy extremities. Electrocardiogram (ECG) showed ST-elevation in leads V3 to V6. Cardiac troponin was elevated, and echocardiography revealed left ventricular segmental hypokinesia and depressed systolic function. Patient was diagnosed with acute anterolateral wall STEMI. Coronary angiogram revealed total occlusion of the mid segment of the left anterior descending artery (LAD), while the rest of the coronary arteries were strikingly normal. After initial balloon angioplasty and stenting of the mid LAD, coronary artery dissection was noted at the distal LAD. A stent was successfully deployed, achieving thrombolysis-in-myocardial-infarction (TIMI) flow grade III with no residual stenosis. Patient remained stable and was discharged improved. Discussion: STEMI rarely happens in young adults. Moreover, literature highlights the rarity of STEMI caused by SCAD. SCAD usually occurs among young pregnant patients who have no risk factors for atherosclerosis. In this report, we highlight the importance of suspecting SCAD among young patients who present with STEMI and of prompt treatment with revascularization in similar clinical situations. Conclusion: SCAD remains a rare cause of STEMI, but it should be considered when young individuals present with STEMI. Treatment is primarily urgent revascularization especially if there is persistent chest pain or ischemic ECG changes, hemodynamic instability, or unstable arrhythmia. Keywords: spontaneous coronary artery dissection, SCAD, acute coronary syndrome, ACS, ST-elevation myocardial infarction, STEMI

Electrocardiogram pearl: ST-T changes in patient with chest pain – Ischemia or infarction?

Most common electrocardiogram (ECG) findings of myocardial ischemia are ST segment deviations & T wave (ST-T) alterations. However, multiple other conditions can cause ST-T changes mimicking ischemia including ventricular hypertrophy, bundle branch block, electrolyte imbalance, drugs, channelopathies, etc. Uncommonly, incorrect placement of limb leads can also produce ST-T changes leading to diagnostic dilemma. We report a case of erroneous limb-lead placement in a 45 years male mimicking ischemic ECG changes.

The Use of Very Low Concentrations of High-sensitivity Troponin T to Rule Out Acute Myocardial Infarction Using a Single Blood Test.

Recent single-center and retrospective studies suggest that acute myocardial infarction (AMI) could be immediately excluded without serial sampling in patients with initial high-sensitivity cardiac troponin T (hs-cTnT) levels below the limit of detection (LoD) of the assay and no electrocardiogram (ECG) ischemia. We aimed to determine the external validity of those findings in a multicenter study at 12 sites in nine countries. TRAPID-AMI was a prospective diagnostic cohort study including patients with suspected cardiac chest pain within 6 hours of peak symptoms. Blood drawn on arrival was centrally tested for hs-cTnT (Roche; 99th percentile = 14 ng/L, LoD = 5 ng/L). All patients underwent serial troponin sampling over 4-14 hours. The primary outcome, prevalent AMI, was adjudicated based on sensitive troponin I (Siemens Ultra) levels. Major adverse cardiac events (MACE) including AMI, death, or rehospitalization for acute coronary syndrome with coronary revascularization were determined after 30 days. We included 1,282 patients, of whom 213 (16.6%) had AMI and 231 (18.0%) developed MACE. Of 560 (43.7%) patients with initial hs-cTnT levels below the LoD, four (0.7%) had AMI. In total, 471 (36.7%) patients had both initial hs-cTnT levels below the LoD and no ECG ischemia. These patients had a 0.4% (n = 2) probability of AMI, giving 99.1% (95% confidence interval [CI] = 96.7% to 99.9%) sensitivity and 99.6% (95% CI = 98.5% to 100.0%) negative predictive value. The incidence of MACE in this group was 1.3% (95% CI = 0.5% to 2.8%). In the absence of ECG ischemia, the detection of very low concentrations of hs-cTnT at admission seems to allow rapid, safe exclusion of AMI in one-third of patients without serial sampling. This could be used alongside careful clinical assessment to help reduce unnecessary hospital admissions.

Electrocardiographic indicators of acute coronary syndrome are more common in patients with ambulance transport compared to those who self-transport to the emergency department journal of electrocardiology

IntroductionThe American Heart Association recommends individuals with symptoms suggestive of acute coronary syndrome (ACS) activate the Emergency Medical Services' (EMS) 911 system for ambulance transport to the emergency department (ED), which enables treatment to begin prior to hospital arrival. Despite this recommendation, the majority of patients with symptoms suspicious of ACS continue to self-transport to the ED. The IMMEDIATE AIM study was a prospective study that enrolled individuals who presented to the ED with ischemic symptoms. ObjectivesThe purpose of this secondary analysis was to determine differences in patients presenting the ED for possible ACS who arrive by ambulance versus self-transport on: 1) time-to-initial hospital electrocardiogram (ECG), 2) presence of ischemic ECG changes, and 3) patient characteristics. MethodsInitial 12-lead ECGs acquired upon patient arrival to the ED were evaluated for ST-elevation, ST-depression, and T-wave inversion.ECG signs of ischemia were analyzed both individually and collapsed into an independent dichotomous variable (ED ECG ischemia yes/no) for statistical analysis. Patient characteristics tested included: gender, age, race, ethnicity, English speaking, living alone, mode of transport, and presenting symptoms (chest pain, jaw pain, shortness of breath, nausea/vomiting, syncope, and clinical history). ResultsIn 1299 patients (mean age 63.9, 46.7% male), 384 (29.6%) patients arrived by ambulance to the ED. The mean time-to-initial ECG was 47minutes for ambulance patients versus 53minutes for self-transport patients (p<0.001). Mode of transport was found to be an independent predictor for time-to-initial ECG controlling for age, gender, and race (p=0.004). There were significantly higher rates of ECG changes of ischemia for patients who arrived by ambulance versus self-transport (p=0.02), and patient characteristics differed by mode of transport to the ED. DiscussionOur findings indicate that less than 30% of individuals with symptoms of ACS activate the EMS ‘911’ system for ambulance transport to the ED. Individuals more likely to activate 911 have timelier ECG but higher rates of ischemic changes, specifically ST-depression and T-wave inversion. Individuals least likely to activate 911 are women, younger individuals, Latino ethnicity, live with a significant other, and those experiencing chest or jaw pain.

Impact of epicardial adipose tissue volume quantified by non-contrast electrocardiogram-gated computed tomography on ergonovine-induced epicardial coronary artery spasm

ObjectiveEndothelial dysfunction of the coronary artery is thought to lead to the development of coronary spasms. Epicardial adipose tissue may be a marker of coronary atherosclerosis. This study investigated the diagnostic impact of epicardial fat volume (EFV), quantified with non-contrast electrocardiogram (ECG)-gated computed tomography (CT), on ergonovine-induced coronary spasms. MethodsWe included 97 patients with suspected coronary spastic angina who underwent ECG-gated CT and an ergonovine provocation test. The EFV was measured with CT data sets using dedicated software. Coronary spasm was defined as total or subtotal occlusion (compared with the relaxed state after nitroglycerin) that was associated with ischemic ECG changes and concurrent chest pain. ResultsCoronary spasms were observed in 27 patients (28%). The EFV was significantly higher in patients with spasms compared with those without spasms (175.0±57.8cm3 vs. 129.7±57.8cm3, p<0.01). Univariate logistic regression analyses indicated significant relationships between coronary spasms and EFV (per 10cm3, odds ratio (OR): 1.13; p<0.01), male gender (OR: 3.34; p<0.01), and smoking (OR: 3.42; p<0.01). In the multivariate model, EFV (per 10cm3, OR: 1.10; p=0.03) and male gender (OR: 5.94; p=0.02) remained significant predictors of coronary spasm. The optimal EFV threshold for predicting coronary spasm was 149.4cm3, identified with a receiver operating characteristic curve. ConclusionsIncreased EFV was associated with ergonovine-induced epicardial coronary artery spasms.

Electrocardiographic Responses to Deer Hunting in Men and Women

Deer hunting includes various stimuli resulting in augmented sympathetic activity, increased heart rate (HR) response, and rhythm changes. Collectively, these superimposed stresses may increase an individual's risk for cardiovascular events. We undertook this study to evaluate HR and rhythm responses in multiple phases of deer hunting in men and women with and without cardiovascular disease (CVD). Nineteen participants age 38.3 ± 13.8 years (mean ± SD) with body mass index 29.2 ± 6.9 kg/m(2) followed their normal hunting routine. HR and rhythm were recorded continuously during the hunt using a small leadless electrocardiogram (ECG) patch monitor. Data were collected on 13 of 19 hunters while hiking. Three hunters recorded HR ≥85% of their age-predicted heart rate maximum (HRmax) for 1 to 2 minutes. Arrhythmias were detected in both participants with CVD and in 8 without CVD. Recorded rhythms included premature atrial, junctional, and ventricular complexes. Six hunters climbed a tree stand; 3 of them recorded HR ≥85% HRmax with sustained elevated HR response for 2 to 3 minutes with premature junctional contractions. Four of 19 participants dragged deer carcasses. During the drag, 1 male hunter recorded an HR of 91% HRmax, and another male hunter without CVD recorded an exercise-induced ischemic ECG. Fifteen of 19 hunters experienced "buck fever" (acute extreme excitation), with 7 reaching ≥85% HRmax for up to 1 minute. Ventricular bigeminy and trigeminy and ventricular couplets were observed in 1 subject during buck fever. Men and women with and without CVD recorded substantial increases in HR and clinically relevant arrhythmias while deer hunting.