Cardiac and non-cardiac causes of T-wave inversion in the precordial leads in adult subjects: A Dutch case series and review of the literature

Advancing Fairness in Cardiac Care: Strategies for Mitigating Bias in Artificial Intelligence Models Within Cardiology

In the dynamic field of medical artificial intelligence (AI), cardiology stands out as a key area for its technological advancements and clinical application. In this review we explore the complex issue of data bias, specifically addressing those encountered during the development and implementation of AI tools in cardiology. We dissect the origins and effects of these biases, which challenge their reliability and widespread applicability in health care. Using a case study, we highlight the complexities involved in addressing these biases from a clinical viewpoint. The goal of this review is to equip researchers and clinicians with the practical knowledge needed to identify, understand, and mitigate these biases, advocating for the creation of AI solutions that are not just technologically sound, but also fair and effective for all patients.

ST segment and T wave abnormalities: A narrative review

INTRODUCTION

The electrocardiogram (ECG) is a valuable tool for interpreting ventricular repolarization. This article aims to broaden the diagnostic scope beyond the conventional ischemia-centric approach, integrating an understanding of pathophisiological influences on ST-T wave changes.

METHODS

A review was conducted on the physiological underpinnings of ventricular repolarization and the pathophisiological processes that can change ECG patterns. The research encompassed primary repolarization abnormalities due to uniform variations in ventricular action potential, secondary changes from electrical or mechanical alterations, and non-ischemic conditions influencing ST-T segments.

RESULTS

Primary T waves are characterized by symmetrical waves with broad bases and variable QT intervals, indicative of direct myocardial action potential modifications due to ischemia, electrolyte imbalances, and channelopathies. Secondary T waves are asymmetric and often unassociated with significant QT interval changes, suggesting depolarization alterations or changes in cardiac geometry and contractility.

CONCLUSION

We advocate for a unified ECG analysis, recognizing primary and secondary ST-T changes, and their clinical implications. Our proposed analytical framework enhances the clinician's ability to discern a wide array of cardiac conditions, extending diagnostic accuracy beyond myocardial ischemia.

Longitudinal ECG changes among adults with HIV in Tanzania: A prospective cohort study

The prevalence of cardiovascular disease (CVD) is rising among people with HIV (PWH) in sub-Saharan Africa (SSA). Despite the utility of the electrocardiogram (ECG) in screening for CVD, there is limited data regarding longitudinal ECG changes among PWH in SSA. In this study, we aimed to describe ECG changes over a 6-month period in a cohort of PWH in northern Tanzania. Between September 2020 and March 2021, adult PWH were recruited from Majengo HIV Care and Treatment Clinic (MCTC) in Moshi, Tanzania. Trained research assistants surveyed participants and obtained a baseline ECG. Participants then returned to MCTC for a 6-month follow-up, where another ECG was obtained. Two independent physician adjudicators interpreted baseline and follow-up ECGs for rhythm, left ventricular hypertrophy (LVH), bundle branch blocks, ST-segment changes, and T-wave inversion, using standardized criteria. New ECG abnormalities were defined as those that were absent in a patient's baseline ECG but present in their 6-month follow-up ECG. Of 500 enrolled participants, 476 (95.2%) completed follow-up. The mean (± SD) age of participants was 45.7 (± 11.0) years, 351 (73.7%) were female, and 495 (99.8%) were taking antiretroviral therapy. At baseline, 248 (52.1%) participants had one or more ECG abnormalities, the most common of which were LVH (n = 108, 22.7%) and T-wave inversion (n = 89, 18.7%). At six months, 112 (23.5%) participants developed new ECG abnormalities, including 40 (8.0%) cases of new T-wave inversion, 22 (4.6%) cases of new LVH, 12 (2.5%) cases of new ST elevation, and 11 (2.3%) cases of new prolonged QTc. Therefore, new ECG changes were common over a relatively short 6-month period, which suggests that subclinical CVD may develop rapidly in PWH in Tanzania. These data highlight the need for additional studies on CVD in PWH in SSA and the importance of routine CVD screening in this high-risk population.

Six-month blood pressure and glucose control among HIV-infected adults with elevated blood pressure and hyperglycemia in northern Tanzania: A prospective observational study

BACKGROUND

People with HIV in sub-Saharan Africa are increasingly developing age-related comorbidities. The purpose of this prospective observational study was to describe 6-month outcomes among Tanzanians with HIV and elevated blood pressure or hyperglycemia under current care pathways.

METHODS

Adults presenting for routine HIV care were enrolled and underwent blood pressure and blood glucose measurements. Participants with abnormal blood pressure or glucose were referred for further care, as per current guidelines. Participants' blood pressure and point-of-care glucose were re-evaluated during their 6-month follow-up visit. Elevated blood pressure was defined as systolic ≥140 mmHg or diastolic ≥90 mmHg. Hyperglycemia was defined as fasting glucose ≥126 mg/dl or random glucose ≥200 mg/dl. An electrocardiogram was obtained at enrollment and at follow-up. Interim myocardial infarction and interim myocardial ischemia were defined as new pathologic Q waves and new T-wave inversions, respectively.

RESULTS

Of 500 participants, 155 had elevated blood pressure and 17 had hyperglycemia at enrolment. At 6-month follow-up, 7 (4.6%) of 155 participants with elevated blood pressure reported current use of an anti-hypertensive medication, 100 (66.2%) had persistent elevated blood pressure, 12 (7.9%) developed interim myocardial infarction, and 13 (8.6%) developed interim myocardial ischemia. Among 17 participants with hyperglycemia, 9 (56%) had persistent hyperglycemia at 6 months and 2 (12.5%) reported current use of an anti-hyperglycemic medication.

CONCLUSIONS

Interventions are needed to improve non-communicable disease care pathways among Tanzanians with HIV.

Cardiac Concerns in the Pediatric Athlete

Cardiovascular disease remains the number one cause of death in Americans. It is no secret that exercise mitigates this risk. Exercise and regular physical activity are beneficial for physical health including aerobic conditioning, endurance, strength, mental health, and overall improved quality of life. Unfortunately, today many children and adolescents are sedentary, lacking the recommended daily amount of physical activity, leading to higher rates of obesity, cardiovascular disease, stroke, diabetes, anxiety, and depression. Given this rising concern, the World Health Organization launched a 12-year plan to improve physical activity in children and adolescents by reducing the inactivity rate by 15% in the world. How does this apply to children and adolescents with acquired or congenital heart disease?.

From 12 to 1 ECG lead: multiple cardiac condition detection mixing a hybrid machine learning approach with a one-vs-rest classification strategy

OBJECTIVE

Detecting different cardiac diseases using a single or reduced number of leads is still challenging. This work aims to provide and validate an automated method able to classify ECG recordings. Performance using complete 12-lead systems, reduced lead sets, and single-lead ECGs is evaluated and compared.

APPROACH

Seven different databases with 12-lead ECGs were provided during the PhysioNet/Computing in Cardiology Challenge 2021, where 88,253 annotated samples associated with none, one, or several cardiac conditions among 26 different classes were released for training, whereas 42,896 hidden samples were used for testing. After signal preprocessing, 81 features per ECG-lead were extracted, mainly based on heart rate variability, QRST patterns and spectral domain. Next, a One-vs-Rest classification approach made of independent binary classifiers for each cardiac condition was trained. This strategy allowed each ECG to be classified as belonging to none, one or several classes. For each class, a classification model among two binary Supervised Classifiers and one Hybrid Unsupervised-Supervised classification system was selected. Finally, we performed a 3-fold cross-validation to assess the system's performance.

MAIN RESULTS

Our classifiers received scores of 0.39, 0.38, 0.39, 0.38, and 0.37 for the 12, 6, 4, 3 and 2-lead versions of the hidden test set with the Challenge evaluation metric (CM). Also, we obtained a mean G-score of 0.80, 0.78, 0.79, 0.79, 0.77 and 0.74 for the 12, 6, 4, 3, 2 and 1-lead subsets with the public training set during our 3-fold cross-validation.

SIGNIFICANCE

We proposed and tested a machine learning approach focused on flexibility for identifying multiple cardiac conditions using one or more ECG leads. Our minimal-lead approach may be beneficial for novel portable or wearable ECG devices used as screening tools, as it can also detect multiple and concurrent cardiac conditions.

New Precordial T Wave Inversions in Hospitalized Patients

BACKGROUND

The incidence of precordial T changes has been described in athletes and in specific populations, while the etiology in a large patient population admitted to the hospital has not previously been reported.

METHODS

All electrocardiograms (ECGs) read by the same physician with new (compared to prior ECGs) or presumed new (no prior ECGs) precordial T wave inversions of >1 mm (0.1 mV) in multiple precordial leads were retrospectively reviewed and various ECG, patient-related, and imaging parameters assessed. A total of 226 patients and their ECGs were initially selected for analysis. Of these, 35 were eliminated leaving 191 for the final analysis.

RESULTS

Patients and their ECGs were divided into 5 groups based on diagnosis and incidence including Wellens syndrome, takotsubo, type 2 myocardial infarction, other (including multiple diagnoses), and unknown. Although subtle differences including number of T inversion leads, depth of T waves, QTc intervals, and other variables were present between some groups, diagnosis in individual cases required appropriate clinical, laboratory, or imaging studies. For example, although Wellens syndrome was identified in <20% of cases, a presenting history of chest discomfort with precordial T changes either on the admission or next-day ECG was highly sensitive and specific for this diagnosis. In some cases, type 2 myocardial infarction can also have a Wellens-like ECG phenotype without significant left anterior descending disease.

CONCLUSIONS

Precordial T wave changes in hospitalized patients have various etiologies, and in individual cases, the changes on the ECG alone cannot easily distinguish the presumptive diagnosis and additional data are required.

Remote Analysis and Transmission System of Electrocardiogram in Prehospital Setting; a Diagnostic Accuracy Study

INTRODUCTION

One of the trends in the development of medical technologies is considered to be telemedicine. This study aimed to evaluate the accuracy of a remote electrocardiogram (ECG) analysis and transmission system in prehospital setting.

METHODS

In this cross-sectional study, the data of 19,265 ECGs was gathered from emergency medical service (EMS) database of Almaty city, Kazakhstan, from 2015 to 2019. All ECGs were recorded in the prehospital setting by a paramedic, using "Poly-Spectrum" ECG recording device. Subsequently, all ECGs were sent to the cardiologist for interpretation and the findings were compared between software and cardiologist.

RESULTS

19,265 ECGs were registered. The average time from taking ECGs to receiving an expert's conclusion was 9.2 ± 2.5 minutes. The medical teams were called in 17.9% of cases after paramedic ECG recording; however, in the rest of the cases there was no need to call those teams. Using the device reduced the number of visits of specialist teams. The overall sensitivity, specificity, and accuracy of ECG analysis device in diagnosis of ECG abnormalities were 83.8% (95%CI: 82.6 - 84.9), 95.5% (95%CI: 95.1 - 95.8), and 93.3% (95%CI: 92.9 - 93.7), respectively.

CONCLUSION

The findings of this study showed the 93.3% accuracy of automatic ECG analysis device in interpretation of ECG abnormalities in prehospital setting compared with the cardiologist interpretations. Using the device causes a decrease in the number of cardiologist visits needed as well as reduction in cost and elapsed time.

An idiopathic case of precordial deep T-wave inversion

Introduction and importance

One percent of the patients referred to cardiac intensive care unit (CICU) are presented with T-wave inversion.

Case presentation

We present a case of 78-year-old woman with chest pain and dyspnea. ECG showed precordial deep T-wave inversion.

Clinical discussion

Cardiomyopathies, ischemia and other pathologies were ruled out.

Conclusion

It is likely to be a first reported case of idiopathic deep T-wave inversion seen in the family without any cardiac or non-cardiac etiology.

•

T-wave inversion is commonly presented in electrocardiogram (ECG) of infants.

•

Precordial lead T-wave inversion is seen in infants and can be seen in childhood period as well.

•

Familial clustering of this type of ECG was attractive.

•

Genetic analysis of these findings can give more meaningful conclusions.

When Manual Analysis of 12-Lead ECG Holter Plays a Critical Role in Discovering Unknown Patterns of Increased Arrhythmogenic Risk: A Case Report of a Patient Treated with Tamoxifen and Subsequent Pneumonia in COVID-19

Several medicines, including cancer therapies, are known to alter the electrophysiological function of ventricular myocytes resulting in abnormal prolongation and dispersion of ventricular repolarization (quantified by multi-lead QTc measurement). This effect could be amplified by other concomitant factors (e.g., combination with other drugs affecting the QT, and/or electrolyte abnormalities, such as especially hypokalemia, hypomagnesaemia, and hypocalcemia). Usually, this condition results in higher risk of torsade de point and other life-threatening arrhythmias, related to unrecognized unpaired cardiac ventricular repolarization reserve (VRR). Being VRR a dynamic phenomenon, QT prolongation might often not be identified during the 10-s standard 12-lead ECG recording at rest, leaving the patient at increased risk for life-threatening event. We report the case of a 49-year woman, undergoing tamoxifen therapy for breast cancer, which alteration of ventricular repolarization reserve, persisting also after correction of concomitant recurrent hypokalemia, was evidenced only after manual measurements of the corrected QT (QTc) interval from selected intervals of the 12-lead ECG Holter monitoring. This otherwise missed finding was fundamental to drive the discontinuation of tamoxifen, shifting to another "safer" therapeutic option, and to avoid the use of potentially arrhythmogenic antibiotics when treating a bilateral pneumonia in recent COVID-19.

Transient deep and giant negative T waves in dogs with myocardial injury

INTRODUCTION

Although transient deep and giant negative T waves (NTWs) may develop during myocardial injury (MI) in humans, no data exist on this repolarization abnormality in canine MI. Therefore, this study aimed to describe the occurrence of transient deep/giant NTWs in dogs with MI.

ANIMALS, MATERIALS AND METHODS

Medical records were retrospectively searched to identify dogs with MI and transient deep/giant NTWs. Signalment, history, and selected diagnostic test results were reviewed. Data analysis was descriptive.

RESULTS

Six cases were diagnosed with MI associated with deep (n = 1) and giant (n = 5) transient NTWs. Myocardial injury was classified as acute in all cases and was due to snake envenomation (n = 3), sepsis (n = 2), and systemic inflammatory response syndrome (n = 1). At the time of deep/giant NTWs identification, all dogs had elevated cardiac troponin I and ≥1 echocardiographic abnormality of the left ventricular structure and/or function. Moreover, all dogs with giant NTWs had prolonged QT intervals. After the MI resolution, T-wave polarity and QT-interval duration became normalized in all dogs. Moreover, left ventricular morphological and functional parameters were completely normalized in four dogs. In contrast, ventricular echogenicity remained heterogeneous in two dogs, despite otherwise normalized ventricular parameters. Five dogs were still alive at the conclusion of the study.

CONCLUSIONS

Transient deep/giant NTWs may develop in dogs with acute MI and T-wave polarity changes seem to occur synchronously with the evolution of myocardial damage. Moreover, transient deep/giant NTWs seem associated with a favorable prognosis in canine MI.

Abnormal Cardiac Repolarization After Seizure Episodes in Structural Brain Diseases: Cardiac Manifestation of Electrical Remodeling in the Brain?

Background

Abnormal cardiac repolarization is observed in patients with epilepsy and can be associated with sudden death. We investigated whether structural brain abnormalities are correlated with abnormal cardiac repolarizations in patients with seizure or epilepsy.

Methods and Results

We retrospectively analyzed and compared 12‐lead ECG parameters following seizures between patients with and without structural brain abnormalities. A total of 96 patients were included: 33 women (17 with and 16 without brain abnormality) and 63 men (44 with and 19 without brain abnormality). Brain abnormalities included past stroke, chronic hematoma, remote bleeding, tumor, trauma, and postsurgical state. ECG parameters were comparable for heart rate, PR interval, and QRS duration between groups. In contrast, corrected QT intervals evaluated by Fridericia, Framingham, and Bazett formulas were prolonged in patients with brain abnormality compared with those without (women: Fridericia [normal versus abnormal], 397.4±32.7 versus 470.9±48.9; P=0.002; Framingham, 351.0±40.1 versus 406.2±46.1; P=0.002; Bazett, 423.8±38.3 versus 507.7±56.6; P<0.0001; men: Fridericia, 403.8±30.4 versus 471.0±47.1; P<0.0001; Framingham, 342.7±36.4 versus 409.4±45.8; P<0.0001; Bazett, 439.3±38.6 versus 506.2±56.8; P<0.0001). QT dispersion and T_peak−T_end intervals were comparable between groups. We also observed abnormal ST‐segment elevation in 5 patients. Importantly, no patients showed fatal arrhythmias during or after seizures.

Conclusions

Our study demonstrated that brain abnormalities can be associated with abnormal cardiac repolarization after seizures, which might be a manifestation of electrophysiological remodeling in the brain.

Rupturing Abdominal Aneurysm Presenting as Acute Coronary Syndrome

A 61-year-old male presented to the emergency ward with pain in his upper abdomen. Due to an abnormal electrocardiogram (ECG) and elevated cardiac enzymes the cardiologist was consulted to exclude cardiac pathology. The consulting cardiologist advised to exclude an abdominal diagnosis before treating the condition as an acute coronary syndrome (ACS). Before noninvasive imaging had been performed, the clinical situation deteriorated and an emergency laparotomy revealed a ruptured aortic aneurysm. Despite immediate revascularization multiple organ failure ensued and the patient died a few days later. This case illustrates that the suspicion of ACS should never delay the investigation of other life-threatening disorders. Contrarily angina, ECG abnormalities, and myocardial ischemia are all well known to concur with major vascular, intra-abdominal, intra-cranial, and pulmonary pathology; hence these other life-threatening conditions should always be considered and preferably be ruled out prior to further investigation and treatment of ACS.

ELECTROCARDIOGRAM CHANGES IN ADDISON DISEASE: POTENTIAL CLINICAL MARKER FOR ADRENAL CRISIS

Objective

To present a unique phenomenon of a patient in addisonian crisis with electrocardiogram (ECG) anomalies that resolved following glucocorticoid therapy.

Methods

We present the case report followed by discussion with literature review.

Results

A 25-year-old male with Addison disease (AD) presented with a 1-week history of lightheadedness, shortness of breath, chest pain, abdominal pain, postural hypotension, and tachycardia. The patient was diagnosed with addisonian crisis and started on intravenous, high-dose glucocorticoids. An ECG showed right-heart axis deviation and T-wave inversions. In the context of ongoing chest pain, there was concern for myocardial ischemic attack and the patient underwent an extensive cardiac evaluation. Cardiac workup was negative and an echocardiogram showed an ejection fraction of 50 to 55%. The ECG abnormalities resolved 1 day into his hospital admission and his other symptoms resolved 2 days following treatment with steroids.

Conclusion

AD is a rare, potentially lethal, and commonly misdiagnosed disease often first encountered clinically amidst an incident episode of adrenal crisis. Our AD patient was undergoing an adrenal crisis with ECG changes positive for probable cardiac ischemia. Glucocorticoid deficiency has been previously linked with decreased cardiac function and myocardial ischemia, though the underlying mechanisms are not fully clear. This patient recovered within 2 days after receiving corticosteroid supplementation. There have been similar cases previously reported. In each of these, patients underwent extensive and costly workup to evaluate cardiac function, yet all patients fully recovered with corticosteroids. Understanding the physiology and clinical presentation of adrenal crisis will be useful in establishing an earlier diagnosis, thus preventing mortality and avoiding unnecessary, expensive evaluations.

Late T-wave inversion following resolution of non-ischemic acute pulmonary edema

Electrocardiographic (ECG) changes occurring several hours after the onset of acute cardiogenic pulmonary edema have been seldom described. The proposed explanatory mechanisms are various and not fairly established. In the absence of significant coronary artery disease, these ECG abnormalities could be attributed to mechanisms implicated in coronary microcirculatory dysfunction.

The association between T wave inversion and apical hypertrophic cardiomyopathy

Objectives Electrocardiograhy (ECG) is the first step in hypertrophic cardiomyopathy (HCMP) diagnosis. For various reasons, the T wave inversion (TWI) and ECG change with time and HCMP is not easy to diagnosis. The aim of this retrospective study was to investigate the association between TWI on ECG and apical HCMP. Methods A total of 4,730 ECGs presenting TWI from January 2011 to March 2013 in Pusan National University Hospital were enrolled. 133 patients who were examined by both echocardiography and coronary angiogram were analyzed. Patients were divided into two groups: Group A (TWI ≥ 10 mm) and Group B (5 mm ≤ TWI &lt; 10 mm). HCMP is defined by a wall thickness ≥ 15mm in one or more LV myocardial segments. Apical HCMP is defined to be hypertrophy that is confined to LV apex. The patients who had ECGs with at least one month interval were divided 3 groups: Normal T wave, Abnormal T wave, and Persistent TWI. The prevalence of Apical HCMP and coronary artery disease (CAD) was reviewed among the three groups. Results In this study there were a total 133 patients, with patients divided into Group A which had 15 patients and Group B which had 118 patients. Among the 23 patients with apical HCMP, three patients were Group A and twenty patients were Group B ( P = 0.769). Regarding constancy of TWI, persistent TWI group was higher in apical HCMP than in other groups ( P = 0.038). CAD had no difference between groups ( P = 0.889). Conclusions T wave negativity was not associated with incidence of apical HCMP. However, apical HCMP was diagnosed more frequently in patients with persistent TWI. Further follow up echocardiographic study is needed to evaluate the progression of apical HCMP in patients with TWI.

Comparison between Negative T waves characteristics in acute coronary syndrome and pulmonary embolism

BACKGROUND

Electrocardiogram (ECG) is the first available modality used in patients with chest pain and dyspnea in emergency rooms. We aimed to study differences between acute coronary syndrome (ACS) and acute pulmonary embolism (APE) in patients presented primarily with abnormal negative T waves on their admission Electrocardiogram.

METHODS

This research was a retrospective study in which 297 patients (97 patients with APE and 200 with ACS) were included. The patients were admitted to the emergency ward of a tertiary heart center between 2015 and 2017. In addition to the evaluation of distribution of negative T waves, the depth of the inverted precordial T waves was measured.

RESULTS

The mean age of patients was 62.0 ± 11.4 in ACS group and 60.7 ± 17.6 in APE group (P value = 0.563). Total negative T in V3 and V4 in ACS and APE groups was 9.1 mm and 4.2 mm respectively (P value <0.001). Total magnitude of negative T in anterior leads divided by total magnitude of negative T in inferior leads for ACS and APE groups were 15.1 ± 12.0 and 5.4 ± 3.6 respectively (P value = 0.001). ROC curves showed that total magnitude of negative T in V4 divided by negative T in V1 can be valuable. A cutoff point of 1.75 with sensitivity of 73.5% and specificity of 84.9% (95% CI 0.79-0.91 P < 0.001) could differentiate APE patients from ACS patients.

CONCLUSION

This study suggests that total magnitude of negative T in left precordial leads divided by right precordial leads can be valuable in differentiating APE from ACS.

Alpha lipoic acid intoxicatıon: An adult

INTRODUCTION

Alpha lipoic acid (ALA) is a potent antioxidant used to treat a variety of disorders. Although ALA is considered a very safe supplement and intoxication is very rare, acute high-dose ingestions can cause mortality. In this report, we discuss a very rare case of ALA intoxication to increase awareness of this issue.

CASE REPORT

A 22-year-old female was referred to our emergency department with ALA intoxication after ingesting a total of 18g of ALA with a suicidal intention. The patient was found in an altered mental state and confused. During the physical examination, the patient's Glasgow Coma Scale was 13 (E4M6V3); however, she was neither alert nor oriented. Vital signs revealed a mildly decreased blood pressure, tachycardia, and an increased respiratory rate. Cranial nerve examination was normal except a horizontal gaze nystagmus. Laboratory testing showed a decompensated metabolic acidosis. T wave inversions were seen in the electrocardiography (EKG). The patient was treated with supportive treatment and discharged within three days of intensive care unit (ICU) admission.

CONCLUSION

ALA is a very common supplement that is easily accessible worldwide. Although ALA intoxication is very rare, it is sometimes seen after accidental or suicidal acute ingestion. Neurologic effects, metabolic acidosis, and t wave inversions in the EKG are observed when this acute poisoning occurs. Supportive treatment should be the main therapy.

T-Wave Abnormality as Electrocardiographic Signature of Myocardial Edema in Non-ST-Elevation Acute Coronary Syndromes

Background

T‐wave abnormalities are common during the acute phase of non‐ST‐segment elevation acute coronary syndromes, but mechanisms underlying their occurrence are unclear. We hypothesized that T‐wave abnormalities in the presentation of non‐ST‐segment elevation acute coronary syndromes correspond to the presence of myocardial edema.

Methods and Results

Secondary analysis of a previously enrolled prospective cohort of patients presenting with non‐ST‐segment elevation acute coronary syndromes was conducted. Twelve‐lead electrocardiography (ECG) and cardiac magnetic resonance with T2‐weighted imaging were acquired before invasive coronary angiography. ECGs were classified dichotomously (ie, ischemic versus normal/nonischemic) and nominally according to patterns of presentation: no ST‐ or T‐wave abnormalities, isolated T‐wave abnormality, isolated ST depression, ST depression+T‐wave abnormality. Myocardial edema was determined by expert review of T2‐weighted images. Of 86 subjects (65% male, 59.4 years), 36 showed normal/nonischemic ECG, 25 isolated T‐wave abnormalities, 11 isolated ST depression, and 14 ST depression+T‐wave abnormality. Of 30 edema‐negative subjects, 24 (80%) had normal/nonischemic ECGs. Isolated T‐wave abnormality was significantly more prevalent in edema‐positive versus edema‐negative subjects (41.1% versus 6.7%, P=0.001). By multivariate analysis, an ischemic ECG showed a strong association with myocardial edema (odds ratio 12.23, 95% confidence interval 3.65‐40.94, P<0.0001). Among individual ECG profiles, isolated T‐wave abnormality was the single strongest predictor of myocardial edema (odds ratio 23.84, 95% confidence interval 4.30‐132, P<0.0001). Isolated T‐wave abnormality was highly specific (93%) but insensitive (43%) for detecting myocardial edema.

Conclusions

T‐wave abnormalities in the setting of non‐ST‐segment elevation acute coronary syndromes are related to the presence of myocardial edema. High specificity of this ECG alteration identifies a change in ischemic myocardium associated with worse outcomes that is potentially reversible.

Neutropenia and T-Wave Inversion as Toxin-Mediated Complications of a Streptococcal Infection

Introduction

Streptococcal infection can be responsible for multiple complications, such as toxic, septic or allergic disorders. Toxin-mediated complications (TMC) can appear during the acute phase of disease and can involve any organ, causing carditis, arthritis, nephritis, hepatitis etc.

Case presentation

The case of a young woman without a history of recurrent streptococcal tonsillitis, admitted to “Matei Balş” National Institute for Infectious Diseases, Bucharest, Romania, presenting with fever, sore throat and exudative tonsillitis, is detailed. The initial test for Streptococcus pyogenes was negative. The patient had leukopenia with severe neutropenia, high values of inflammatory biomarkers and electrocardiographic (ECG) changes with inverted T waves in leads V1-4 and flattened T waves in V5-6. There were no other cardiac signs or symptoms. The patient received cefuroxime for two days. On admission, the patient was prescribed Penicillin G and dexamethasone which resulted in a rapid recovery. The leucocytes count returned to normal as did the ECG abnormalities. At the time of discharge, the antistreptolysin O titre was high.

Conclusions

The case highlights the toxin-mediated complications (TMC) of streptococcal infection which occur from the outset of the disease.

Unusual Serial Electrocardiographic Changes which Progressed to Arrhythmogenic Right Ventricular Cardiomyopathy

Left ventricular (LV) involvement in the advanced stage of arrhythmogenic right ventricular cardiomyopathy (ARVC) is a well recognized phenomenon. T wave inversion in the lateral leads has been reported to be an electrocardiographic marker of LV involvement. Variants of ARVC that preferentially affect the left ventricle (left-dominant subtype of arrhythmogenic cardiomyopathy) have recently been recognized. We herein report a case in which an initial electrocardiogram that was similar to the left-dominant subtype of arrhythmogenic cardiomyopathy progressed to definitive ARVC over a period of 7 years. This case supports the hypothesis that LV involvement in ARVC may precede the evident onset of significant RV dysfunction.