Abnormal ST-segment changes in anterior and inferior leads during acute inferior myocardial infarction.

Anterior and inferior ST elevation on electrocardiography (ECG) in patients with acute myocardial infarction is uncommon. ST-segment elevation due to right ventricular infarction induced by right coronary occlusion may extend from V1 to V3/V4, resembling the pattern of transmural ischemia of the anterior wall of the left ventricle. In addition, a wraparound left anterior descending (LAD) artery can produce ischemia manifesting as ST-segment elevation in the anterior and inferior leads. Our case report reveals dynamic ST-segment changes in acute inferior myocardial infarction, including the appearance of the shark fin ECG pattern, unlike what has been reported before.

A Case of Reverse Takotsubo Cardiomyopathy After Administering a Local Anesthetic Containing Epinephrine.

Takotsubo cardiomyopathy (TCM) is a rare syndrome characterized by acute and transient distinctive wall motion abnormalities accompanied by other defined objective findings. There are many variants of TCM, including the reverse (or basal) subtype. While the pathogenesis is not fully understood, both endogenous and exogenous catecholamines have been implicated. This case report describes a 30-year-old active-duty military female who developed reverse TCM immediately following local anesthetic with epinephrine administration in preparation for an elective septorhinoplasty. She developed electrocardiogram (ECG) changes, temporary hemodynamic instability, and cardiac troponin elevation. Transthoracic echocardiogram (TTE) demonstrated significantly reduced systolic and diastolic function, with akinesis of the basal segments and normal wall motion of the apical segments, consistent with a reverse Takotsubo pattern. Coronary computed tomography (CT) angiography showed normal coronary arteries. Repeat TTE was performed two days after the initial event and showed near-complete resolution of the wall motion abnormalities. Fourteen days later, TTE showed normalization of cardiac function. While there is a favorable prognosis for most patients with this diagnosis, there does remain the potential for significant adverse outcomes, risk of recurrence, and a non-negligible mortality rate. It is widely known that physical and emotional triggers can precipitate TCM through the release of catecholamines. This case, in addition to numerous other case reports, provides further documentation and support that exogenous epinephrine administration is also associated with the development of TCM. Clinicians should consider the diagnosis of Takotsubo cardiomyopathy if hemodynamic or ECG changes arise following epinephrine administration.

Acute Left Circumflex Coronary Artery Occlusion　- Diagnostic Problems of Initial Electrocardiographic Changes.

Background: Acute coronary syndrome (ACS) with occlusion of the left circumflex coronary artery (LCX) poses diagnostic problems that may lead to a delay in reperfusion. Methods and Results: From a group of 1,269 consecutive patients with ACS, 138 patients with ACS due to LCX occlusion were analyzed for clinical, electrocardiographic, and angiographic presentations, as well as door-to-balloon (DTB) time. Electrocardiographic changes were classified into 4 patterns: ST-segment elevation in inferior/lateral leads (ST-E); ST-segment depression in V1-V4 (ST-D); no significant ST changes (No-ST); and others. The No-ST group was associated with a longer DTB time (P<0.0001) compared with the ST-E and ST-D groups. Compared with the No-ST and ST-E groups, the ST-D group presented with a more advanced Killip class (P=0.003), greater peak creatine phosphokinase (P=0.007) and peak creatine kinase-MB (P=0.006), more frequent proximal LCX occlusion (P=0.007), and worse 1-year outcomes (P=0.0034). Conclusions: One-third of ACS patients with LCX occlusion showed no ST-segment changes, resulting in significantly longer DTB time. Improving diagnostic accuracy is challenging but critical to avoid delayed reperfusion in these patients without electrocardiographic changes.

Teenager Presenting With Chest Pain and ST-Segment Changes on Electrocardiogram After SARS-CoV-2 Illness: Early Repolarization vs. Acute Pericarditis.

The ST-segment elevation is commonly associated with acute myocardial Infarction. However, there are other non-ischemic causes of ST-elevation. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly contagious illness that continues to plague the world since the first case was reported in China over two years ago. As cases of the diseases become rampant, we have learned more of its complications which can include cardiac and pericardial disease. We present a case report of a young African American male who presented with chest pain six weeks after being diagnosed with SARS-Cov-2 pneumonia. Electrocardiogram (EKG) showed ST-segment changes that were initially presumed to be acute pericarditis. The patient was initially treated with colchicine. After further workup and a second opinion, ST-segment changes were thought to be likely benign early repolarization changes rather than pericarditis. Differential diagnosis of ST-segment changes on EKG in the patient with chest pain is broad. Subtle findings on EKG are important in distinguishing these differentials and should be well known and understood.

Strangulation: A Cause or Mimicker of Global Myocardial Hypoxia on ECG.

ST segment changes are often associated with myocardial ischemia but may be mimickers. We present a 21-year-old male who suffered a cardiac arrest following a suicide attempt by strangulation. Initial ECG revealed diffuse ST depressions and ST elevation in augmented vector right (aVR), concerning myocardial ischemia. However, repeat ECG revealed normal ST segments and an echocardiogram revealed no wall motion abnormalities. This case highlights the effects of systemic hypoxia on cardiac muscle and the need for a broad differential diagnosis when interpreting an ECG. This is invaluable when ST segment changes mimic acute myocardial infarction, but the clinical scenario suggests global hypoxia.

Clinical valuation of ST changes in a group of patients with ventricular arrhythmias: The inSighT Study.

BACKGROUND: The inSighT study was designed to determine the prevalence of ischemic changes as recorded by implantable cardioverter-defibrillator (ICD) ST deviations in intracardiac electrocardiograms (EGM) over the 24 h preceding malignant ventricular arrhythmias (VT/VF). METHODS: The study enrolled patients with known coronary artery disease (CAD) or high risk of future development of CAD implanted with an ICD equipped with an ST monitoring feature (Ellipse™/Fortify Assura™, St. Jude Medical). Device session records were collected at each in-clinic follow-up. EGM ST levels of the beats over the 15 minutes prior to VT/VF events were compared using a t test with those from a baseline period of 23-24 h prior to the VT/VF event. All events with p < .05 were visually inspected to confirm they were evaluable; additional criteria for exclusion from further analysis included inappropriate therapy, aberrant conduction, and occurrence of VT/VF within 24h prior to the current event. RESULTS: The study enrolled 481 ICD patients (64 ± 11 years, 83% male) in 14 countries and followed them for 15±5 months. A total of 165 confirmed VT/VF episodes were observed, of which 71 events (in 56 patients, 34% of all patients with VT/VF) were preceded by significant (p < .05) ST-segment changes unrelated to known non-ischemic causes. None of the analyzed demographic and clinical factors proved to be associated with greater odds of presenting with ST-segment changes prior to VT/VF episode. CONCLUSION: In this exploratory study, characteristic ST-segment changes, likely representative of ischemic events, were observed in 34% of all patients with VT/VF episodes.

Diagnostic value of electrocardiographic ST-segment changes for myocardial injury related to percutaneous coronary intervention / 中国基层医药

Objective:To investigate the diagnostic value of electrocardiographic ST-segment changes for myocardial injury related to percutaneous coronary intervention.Methods:We included 60 patients who received percutaneous coronary intervention in Haining People's Hospital from January 2020 to February 2021 in this study. We detected serum troponin I level before and after treatment and recorded electrocardiographic ST-segment changes. Taking serum troponin I level as a reference, we divided these patients into myocardial injury and non-myocardial injury groups and analyzed the influential factors of myocardial injury.Results:Balloon inflation time and stent length were (85.6 ± 56.2) minutes and (25.2 ± 15.2) mm in the myocardial injury group, and they were (48.5 ± 39.2) minutes and (17.2 ± 8.2) mm in the non-myocardial injury group. There were no significant differences in balloon inflation time and stent length between the two groups ( t = -3.01, -2.42, both P < 0.05). The proportion of patients with electrocardiographic ST-segment changes was significantly higher in the myocardial injury group than in the non-myocardial injury group [(80.77% (21/26) vs. 5.88% (2/34), χ2= 34.95, P < 0.001). Multivariable logistic regression analysis results showed that electrocardiographic ST-segment changes were an influential factor of myocardial injury ( r = 69.25, P < 0.05). Conclusion:Electrocardiographic ST-segment changes are an independent influential factor of myocardial injury related to percutaneous coronary intervention. It can effectively judge the possibility of developing a myocardial injury and increase the safety of percutaneous coronary intervention.

Transient recovery of epicardial and torso ST-segment ischemic signals during cardiac stress tests: A possible physiological mechanism.

BACKGROUND: Acute myocardial ischemia has several characteristic ECG findings, including clinically detectable ST-segment deviations. However, the sensitivity and specificity of diagnosis based on ST-segment changes are low. Furthermore, ST-segment deviations have been shown to be transient and spontaneously recover without any indication the ischemic event has subsided. OBJECTIVE: Assess the transient recovery of ST-segment deviations on remote recording electrodes during a partial occlusion cardiac stress test and compare them to intramyocardial ST-segment deviations. METHODS: We used a previously validated porcine experimental model of acute myocardial ischemia with controllable ischemic load and simultaneous electrical measurements within the heart wall, on the epicardial surface, and on the torso surface. Simulated cardiac stress tests were induced by occluding a coronary artery while simultaneously pacing rapidly or infusing dobutamine to stimulate cardiac function. Postexperimental imaging created anatomical models for data visualization and quantification. Markers of ischemia were identified as deviations in the potentials measured at 40% of the ST-segment. Intramural cardiac conduction speed was also determined using the inverse gradient method. We assessed changes in intramyocardial ischemic volume proportion, conduction speed, clinical presence of ischemia on remote recording arrays, and regional changes to intramyocardial ischemia. We defined the peak deviation response time as the time interval after onset of ischemia at which maximum ST-segment deviation was achieved, and ST-recovery time was the interval when ST deviation returned to below thresholded of ST elevation. RESULTS: In both epicardial and torso recordings, the peak ST-segment deviation response time was 4.9±1.1 min and the ST-recovery time was approximately 7.9±2.5 min, both well before the termination of the ischemic stress. At peak response time, conduction speed was reduced by 50% and returned to near baseline at ST-recovery. The overall ischemic volume proportion initially increased, on average, to 37% at peak response time; however, it recovered to only 30% at the ST-recovery time. By contrast, the subepicardial region of the myocardial wall showed 40% ischemic volume at peak response time and recovered much more strongly to 25% as epicardial ST-segment deviations returned to baseline. CONCLUSION: Our data show that remote ischemic signal recovery correlates with a recovery of the subepicardial myocardium, whereas subendocardial ischemic development persists.

Pharmacological and simulated exercise cardiac stress tests produce different ischemic signatures in high-resolution experimental mapping studies.

OBJECTIVE: Test the hypothesis that exercise and pharmacological cardiac stressors create different electrical ischemic signatures. INTRODUCTION: Current clinical stress tests for detecting ischemia lack sensitivity and specificity. One unexplored source of the poor detection is whether pharmacological stimulation and regulated exercise produce identical cardiac stress. METHODS: We used a porcine model of acute myocardial ischemia in which animals were instrumented with transmural plunge-needle electrodes, an epicardial sock array, and torso arrays to simultaneously measure cardiac electrical signals within the heart wall, the epicardial surface, and the torso surface, respectively. Ischemic stress via simulated exercise and pharmacological stimulation were created with rapid electrical pacing and dobutamine infusion, respectively, and mimicked clinical stress tests of five 3-minute stages. Perfusion to the myocardium was regulated by a hydraulic occluder around the left anterior descending coronary artery. Ischemia was measured as deflections to the ST-segment on ECGs and electrograms. RESULTS: Across eight experiments with 30 (14 simulated exercise and 16 dobutamine) ischemic interventions, the spatial correlations between exercise and pharmacological stress diverged at stage three or four during interventions (p<0.05). We found more detectable ST-segment changes on the epicardial surface during simulated exercise than with dobutamine (p<0.05). The intramyocardial ischemia formed during simulated exercise had larger ST40 potential gradient magnitudes (p<0.05). CONCLUSION: We found significant differences on the epicardium between cardiac stress types using our experimental model, which became more pronounced at the end stages of each test. A possible mechanism for these differences was the larger ST40 potential gradient magnitudes within the myocardium during exercise. The presence of microvascular dysfunction during exercise and its absence during dobutamine stress may explain these differences.

Characterizing the transient electrocardiographic signature of ischemic stress using Laplacian Eigenmaps for dimensionality reduction.

OBJECTIVE: Despite a long history of ECG-based monitoring of acute ischemia quantified by several widely used clinical markers, the diagnostic performance of these metrics is not yet satisfactory, motivating a data-driven approach to leverage underutilized information in the electrograms. This study introduces a novel metric for acute ischemia, created using a machine learning technique known as Laplacian eigenmaps (LE), and compares the diagnostic and temporal performance of the LE metric against traditional metrics. METHODS: The LE technique uses dimensionality reduction of simultaneously recorded time signals to map them into an abstract space in a manner that highlights the underlying signal behavior. To evaluate the performance of an electrogram-based LE metric compared to current standard approaches, we induced episodes of transient, acute ischemia in large animals and captured the electrocardiographic response using up to 600 electrodes within the intramural and epicardial domains. RESULTS: The LE metric generally detected ischemia earlier than all other approaches and with greater accuracy. Unlike other metrics derived from specific features of parts of the signals, the LE approach uses the entire signal and provides a data-driven strategy to identify features that reflect ischemia. CONCLUSION: The superior performance of the LE metric suggests there are underutilized features of electrograms that can be leveraged to detect the presence of acute myocardial ischemia earlier and more robustly than current methods. SIGNIFICANCE: The earlier detection capabilities of the LE metric on the epicardial surface provide compelling motivation to apply the same approach to ECGs recorded from the body surface.

False-positive electrocardiographic changes during exercise test in a patient with pectus excavatum.

Exercise-induced ST-segment changes simulating myocardial ischemia have been described in otherwise normal subjects during hyperventilation. We present the case of a 60-year-old man with pectus excavatum showing significant exercise-induced "pseudo-ischaemic" ST-segment changes with neither coronary artery disease nor anxiety-induced hyperventilation. We found no report of the possible causative role of a narrow antero-posterior chest diameter in inducing "pseudo-ischaemic" ST-segment changes during exercise stress test in the literature.

Changes in central venous oxygen saturation, lactates, and ST segment changes in a V lead ECG with changes in hemoglobin in neurosurgical patients undergoing craniotomy and tumor excision: A prospective observational study.

BACKGROUND AND AIMS: The aim of the study was to observe the trends in central venous oxygen saturation (ScvO2), lactate, and ST segment changes with change in hemoglobin in patients undergoing acute blood loss during surgery and to assess their role as blood transfusion trigger. MATERIAL AND METHODS: Seventy-seven consecutive patients undergoing craniotomy at a tertiary care institution were recruited for this study after obtaining written, informed consent. After establishing standard monitoring, anesthesia was induced with standard anesthetic protocol. Hemodynamic parameters such as heart rate, blood pressure (mean, systolic, diastolic), pulse pressure variation (PPV), and physiological parameters such as lactate, ScvO2, ST segment changes were checked at baseline, before and after blood transfusion and at the end of the procedure. STATISTICAL ANALYSIS: Comparison of the mean and standard deviation for the hemodynamic parameters was performed between the transfused and nontransfused patient groups. Pearson correlation test was done to assess the correlation between the covariates. Receiver operating characteristic (ROC) curve was constructed for the ScvO2 variable, which was used as a transfusion trigger and the cutoff value at 100% sensitivity and 75% specificity was constructed. Linear regression analysis was done between the change in hemoglobin and the change in ScvO2 and change in hemoglobin and change in the ST segment. RESULTS: There was a statistically significant positive correlation between the change in ScvO2 and change in hemoglobin during acute blood loss with a regression coefficient of 0.8 and also between change in ST segment and hemoglobin with a regression coefficient of -0.132. No significant change was observed with lactate. The ROC showed a ScvO2 cutoff of 64.5% with a 100% sensitivity and 75% specificity with area under curve of 0.896 for blood transfusion requirement. CONCLUSIONS: We conclude that ScvO2 and ST change may be considered as physiological transfusion triggers in patients requiring blood transfusion in the intraoperative period.

A case of conservative management for left ventricular giant pseudoaneurysm without ST segment changes.

Left ventricular (LV) rupture after myocardial infarction (MI) occasionally results in formation of LV pseudoaneurysm (LVPA) which is prone to rupture because of its thin wall. However, cases of LVPA without ST changes including segment elevation in electrocardiogram (ECG) are rare. In this case, we describe a patient who had relatively mild symptoms and giant LVPA with no specific ECG changes following MI with a confirmed diagnosis via transthoracic echocardiography. Although surgical treatment options are often recommended, conservative therapy was adopted, following which the patient had been well-medicated using antihypertensive drugs and anticoagulants. .

Prinzmetals angina presenting with non critical lesion with normal FFR -to stent or not to stent.

Variant angina also called Prinzmetals angina is an enigma characterized by transient circadian symptoms of chest pain associated with ECG changes. The patient is symptom free with normal ECG and echo during symptom free periods. We present a case associated with transient ST-segment elevation with non critical lesion with normal FFR.

ST-segment elevation myocardial infarction vs. hypothermia-induced electrocardiographic changes: a case report and brief review of the literature.

BACKGROUND: Diagnosed ST-segment elevation myocardial infarction (STEMI) usually prompts rapid cardiac catheterization response. OBJECTIVE: Our aim was to raise awareness that hypothermia can cause electrocardiographic (ECG) changes that mimic STEMI. CASE REPORT: Emergency Medical Services (EMS) was called for altered mental status and lethargy in a 47-year-old man with a medical history of paraplegia. His history included hepatitis C, hypertension, seizures, anxiety, and recent pneumonia treated with i.v. antibiotics. When brought in by EMS, the patient was responsive only to painful stimuli. His blood glucose was 89 mg/dL; blood pressure was 80/50 mm Hg, and ECG showed ST elevations diffusely. His vital signs in the emergency department were heart rate 53 beats/min, blood pressure 134/79 mm Hg, respiratory rate 14 breaths/min, pulse oximetry of 100%, and a rectal temperature of 32.7°C (91°F). A second ECG showed diffuse ST elevation, sinus bradycardia with a rate of 56 beats/min, and a first-degree atrioventricular block. J waves were noted in V3-V6, I and II. There were no reciprocal changes or ST depressions. A bedside ultrasound showed no pericardial effusion. The patient underwent cardiac catheterization, which showed no coronary artery disease and a normal ejection fraction. Later, hypercapneic respiratory failure with bilateral pneumonia developed and was intubated. His ECG the following day, once he was rewarmed, showed complete resolution of ST elevation and almost complete resolution of J waves. CONCLUSION: Obtaining a complete set of vital signs is key to making a correct diagnosis. Hypothermia should be considered in the differential diagnosis of ST elevation.

Clinical analysis of difference of inferior ST segment change of acute anterior wall myocardial infarction / 中国基层医药

Objective To investigate the clinical characteristics of inferior acute myocardial infarction (IAMI) with different inferior ST segment change.Methods The clinical data of 64 cases with acute anterior wall myocardial infarction from January 2010 to February 2012 in the hospital were prospectivly analyzed.According to wall leads ECG ST segment in the change situation,they were divided into three groups,group A (16 cases),under the wall (]Ⅱ,Ⅲ,aVF) of at least two lead ST segment elevation ≥0.1mV,group B(26 cases) under the wall(Ⅱ,Ⅲ,aVF) of at least two lead ST segment depression,group C (22 cases) under the wall(Ⅱ,Ⅲ,aVF) only a lead or no ST segment change.The infarct related artery,acute anterior wall myocardial infarction with different inferior ST-T change (infarction related coronary artery,IRCA),the infarct size and heart function were studied.Results IRCA in the three groups was consistent.The comparison of IRCA among the three groups showed that,A group of patients with “around the apical LAD” COSCO segment,accounting for 81.25％,and 26 cases in B group were not “around the apical LAD”,which was not “around the apical LAD” in 18 cases,8 cases of non-“ around the apex” COSCO LAD,of 22 patients in C group,21 cases non-“ around the apical LAD”,1 case was “around the apical LAD” COSCO,and the difference was statistically significant(F =6.32,5.92,7.08,4.11,all P ＜ 0.05).Conclusion IRCA is the LAD of acute anterior wall myocardial infarction of inferior ST segment changes may be related with the length of LAD and the lesion site,changes of inferior ST segment of anterior wall AMI can predict the IRCA position and LAD morphology,consistent with most studies.Patients with anterior wall and inferior wall ST segment elevation if IRCA is “around the apical LAD”,the infarction area is smaller,better heart function.