Electrocardiographic Findings Research Articles

Giant T waves and QT interval prolongation associated with guanfacine toxicity.

Guanfacine is a central α2-adrenergic receptor agonist that produces drowsiness, bradycardia, hypotension, and occasionally QT interval prolongation. We discuss giant T waves associated with guanfacine toxicity. Three patients presented to the hospital with histories and physical findings compatible with guanfacine toxicity. Supratherapeutic concentrations were confirmed in two of them. All three developed QT interval prolongation and giant T waves on the electrocardiogram. Giant T waves occur commonly in patients with acute myocardial infarct and hyperkalemia, as well as rarely with a number of other cardiac and non-cardiac causes. Guanfacine toxicity may cause the novel electrocardiographic finding of 'giant T wave with QT interval prolongation'. Further studies are warranted to investigate the association between the novel electrocardiographic finding and guanfacine toxicity, as well as its diagnostic utility in such cases.

Prevalence of abnormal electrocardiographic findings and associated factors among patients with epilepsy at Jimma Medical Center, Ethiopia; Hospital-based cross-sectional study.

A person with epilepsy experiences recurrent seizures as a result of a persistent underlying disorder. About 50 million people globally are impacted by it, with 4 million of those being in Sub-Saharan Africa. One of the most frequent comorbidities that raise the mortality and morbidity rates of epileptic patients is abnormal Electrocardiographic (ECG) findings. Thus, the purpose of this study is to evaluate the prevalence of abnormal ECG findings in epileptic patients that might lead to increased risk of sudden cardiac death. A hospital based cross-sectional study was at Jimma Medical Center of Ethiopia on epileptic patients who were on follow-up at neurologic clinics during the data collection period. The malignant ECG characteristics and was identified using the ECG abnormality tool. To facilitate analysis, the gathered data was imported into Epidata version 3.1 and exported to the SPSS version 26. The factors of abnormal ECG and sudden death risk were examined using bivariate logistic regression. The study comprised 190 epileptic patients, with a mean age of 32 years. There were more men than women, making up 60.2%. A 43.2% (n = 80) frequency of ECG abnormalities was identified. According to the study, early repolarization abnormalities were the most common ECG abnormalities and increased with male sex and the length of time a person had seizures (AOR) of 4.751 and 95% CI (.273,.933), p = 0.029, compared to their female counterparts. The frequency of malignant ECG alterations in epileptic patients on follow-up at Jimma Medical Center in Ethiopia is described in the study. According to the study, there were significant ECG alterations in epileptic individuals. Male gender and longer duration of epilepsy raise the risk of abnormal ECG findings that could result in sudden cardiac death.

Cardiac repolarization abnormalities and neurally mediated syncope: overlooked aspects in the diagnosis of pheochromocytoma

BackgroundPheochromocytoma is a rare catecholamine-producing tumour originating from adrenal chromaffin cells. Classic clinical presentation includes headache, diaphoresis and palpitation. Syncope is uncommon and may result from hypotension or arrhythmia. We report a case of neurally mediated syncope in pheochromocytoma associated with cardiac repolarization abnormalities, a unique presentation of the disease.Case presentationThis case report presents a 28 year-old woman, describing recurrent syncope usually preceded by prodromes such as headache, visual blurring, heart palpitations and psychomotor agitation. Firstly she was diagnosed with anxiety and depression, but there was no improvement of symptoms with psychiatric treatment. Previous Holter revealed long QT interval. Echocardiogram showed normal dimensions, preserved left ventricular function and no valvopathies. The patient was referred for a Head-up tilt test (HUTT) in order to investigate reflex syncope. The electrocardiogram (ECG) exhibited normal sinus rhythm and diffuse cardiac repolarisation abnormalities. HUTT was positive for vasodepressor type neurally mediated syncope and ECG showed U waves after a syncope episode. This electrocardiographic finding motivated further clinical investigation. The patient also described abdominal pain, increased abdominal volume, weight loss and blood pressure instability. Based on clinical history and ventricular repolarisation abnormalities uncovered by HUTT, pheochromocytoma was suspected. Urinary test was positive for catecholamines and the abdominal imaging revelead expansive lesion. She underwent surgery to remove the pheochromocytoma, confirmed by immunohistochemistry.ConclusionsAfter surgery she had no recurrency of symptoms, remaining asymptomatic after six years of follow-up, suggesting a cause-effect relationship between neurally mediated syncope and pheochromocytoma.

Role of Vascular Function in the Prognosis of Heart Failure Patients.

Background: Blood vessels have the Windkessel effect and are involved in blood circulation. The breakdown of this mechanism is also involved in the pathogenesis of heart failure (HF); however, the relationship between vascular dysfunction and HF prognosis is not fully understood. Methods: We evaluated 214 patients hospitalized for HF at our institution who underwent a cardio-ankle vascular index (CAVI), which evaluates vascular function, between January 2012 and July 2018. To investigate factors (including CAVI) associated with major adverse cardiac events (MACE) during 1 year after patients with HF were discharged, we evaluated clinical profiles, blood tests, chest X-P, 12-lead electrocardiography, and transthoracic echocardiographic findings. MACE was defined as cardiovascular death or readmission for HF. Results: The severity of HF between the MACE and non-MACE was not significantly different. Previous HF and chronic kidney disease were significantly more common in the MACE group. CAVI and % mean atrial pressure in the MACE group were statistically higher than those in the non-MACE group. The cardiac shadow as shown by chest X-P and left ventricular size in the MACE group were significantly bigger, and HF preserved ejection fraction (EF) (EF > 50%) was significantly more common in the MACE group. In multivariate analysis, CAVI was an independent predictive factor for the occurrence of MACE (model 1; hazard ratio (HR): 1.33, 95% confidence interval (CI): 1.05-1.68, p = 0.018; model 2; HR: 1.31, 95% CI: 1.07-1.60, p = 0.009). Conclusions: Because high CAVI is associated with poor prognosis of HF, these patients require more careful treatment.

Impact of Smokeless Tobacco on Cardiovascular Disease Risk in a Nigerian Metropolitan City.

The use of smokeless tobacco products (STP) as a substitute for tobacco smoking is driving increasing consumption of these products especially in developing countries. The study sought to make comparison of cardiovascular risk profile between chronic STP users and suitably matched tobacco-naïve controls. This is a preliminary report from the cross sectional part of a two-arm prospective study of Smokeless Tobacco Products Composition and Exposure Outcome in Enugu metropolis, Nigeria. Consecutively recruited current Smokeless tobacco users, who had no history of cigarette smoking, aged 18years and above, residing in selected communities in Enugu metropolis, Nigeria were recruited for the study from October 2022 to July 2023. Age and sex matched non-tobacco users from same localities as the study subjects served as controls. Written informed consent to participate in the study was obtained from all study participants. All participants were screened by the investigators, using the study case report forms, to obtain data on medical history, demographic, clinical, laboratory, and electrocardiographic evaluation. Data from 54 STP-users and 54 non-STP-users (mean age 56.58 ± 8.15years) were analyzed. Anthropometric parameters were similar in both groups. Smokeless tobacco users had higher erect and supine blood pressure indices as well asgreater postural drop in systolic blood pressure. The occurrence of diabetes mellitus (20.37% versus 5.56%) and hypertension (25.93%; 11.11%) was significantly higher in the STP-users than in the non-user population, (p = 0.02192 and 0.04751 respectively). Electrocardiographic evaluation showed significantly increased QTc and dispersions of P-wave, QRS and QT intervals as well as reduced PR interval in STP users. Electrocardiographic abnormalities observed in STP users include left ventricular hypertrophy, left atrial enlargement, ST-segment elevation, short PR interval and long QTc. Use of smokeless tobacco products is associated with increased risk burden of diabetes mellitus and hypertensive heart disease. Electrocardiographic findings linked to STP-use in this study are features consistent with arrhythmia, ventricular repolarization abnormality, myocardial hypertrophy and ischaemia, suggesting that smokeless tobacco products are not safe substitutes for tobacco smoking.

Electrocardiographic abnormalities are prognostic of the clinical outcomes and mortality of patients with subarachnoid hemorrhages

PurposeWe explored the relationships between electrocardiographic (ECG) abnormalities and the clinical outcomes and mortality of patients with non-traumatic aneurysmal subarachnoid hemorrhages (SAHs). MethodsThis retrospective cohort study enrolled consecutive adult patients who presented to emergency departments with non-traumatic aneurysmal SAHs. We recorded their demographics, clinical characteristics, and ECG findings, and explored the relationships between ECG abnormalities, on the one hand, and 28-day mortality and prognosis, on the other. ResultsWe enrolled 158 patients, 76 females (48.10%) and 82 males (51.90%) of average age 54.70 ± 7.07 years. A total of 107 patients (67.72%) exhibited at least one ECG abnormality, most commonly a T-wave change (n = 54, 34.18%). Such patients evidenced significantly higher Hunt-Hess and Fisher scale scores than those without abnormalities (both p < 0.001). Patients with abnormal ECG findings experienced more unfavorable outcomes and higher mortality than others (both p < 0.001). ECG abnormalities, including PR prolongation, pathological Q waves, QRS widening, left bundle branch blocks, premature ventricular contractions, ST segment changes, and T-wave changes, were more common in non-survivors and patients with Hunt-Hess scores of 4–5 compared to survivors and those with Hunt-Hess scores <4, respectively. Moreover, increased age and presence of abnormal ECG findings were independent predictors of mortality in aneurysmal SAHs. ConclusionsPatients with abnormal ECG findings exhibited unfavorable clinical outcomes and increased mortality rates. Abnormal ECG findings combined with higher Hunt-Hess or Fischer grade scores usefully predict adverse clinical outcomes in and mortality of SAH patients.

Are ECG findings overlooked in Lyme disease, which is the cause of AV complete block?

Objective: Lyme disease-associated carditis and conduction disturbances are well known, but there is insufficient data in the literature on the effects of Lyme disease on global electrocardiography (ECG) morphology. This study aims to evaluate the effects of Lyme disease on ECG morphology. Method: The study included 48 consecutive patients who were hospitalised in our centre with a diagnosis of AV complete block between 01 January 2020 and 01 August 2023. Patients were divided into two groups as Lyme positive (Group 1) and negative (Group 2). Afterwards, demographic and laboratory data of the patients were recorded. All ECG data including ventricular rate, atrial rate, QRS duration, P wave dispersion (Pd), QTc dispersion (QTcd), and fragmented QRS were analysed from routine electrocardiograms obtained using standard extremity and chest leads at 25 mm/s and 10 mm/mV. The data obtained were compared between the groups. Results: The mean age was 72.5(51.7-82.2) in group 1 and 74(68-79.7) in group 2, respectively. There was no significant difference between them (P= 0.593). In the study population, the ratio of males and females was similar between the groups. In ECG evaluation of the study population, no significant difference was found between atrial rate, ventricular rate, QRS duration, QTc duration and frequency of fragmented QRS (p

Electrocardiographic Changes after Endovascular Mechanical Thrombectomy in a Patient with Pulmonary Embolism-A Case Report and Literature Review.

Background: Pulmonary embolism (PE) is a common disease with an annual incidence of about 1/1000 persons. About every sixth patient dies within the first 30 days after diagnosis. The electrocardiogram (ECG) is one of the first diagnostic tests performed, and is able to confirm the suspicion of PE with typical electrocardiographic signs. Some ECG signs and their regression are also prognostically relevant. Endovascular mechanical thrombectomy is one option for PE treatment, and aims to relieve right heart strain immediately. The first studies on endovascular mechanical thrombectomy using a dedicated device (FlowTriever System, Inari Medical, Irvine, CA, USA) yielded promising results. Methods: In the following, we report the case of a 66-year-old male patient who presented with New York Heart Association III dyspnea in our emergency department. Among typical clinical and laboratory results, he displayed very impressive electrocardiographic and radiological findings at the time of PE diagnosis. Results: After endovascular mechanical thrombectomy, the patient's complaints and pulmonary hemodynamics improved remarkably. In contrast, the ECG worsened paradoxically 18 h after intervention. Nevertheless, control echocardiography 4 days after the intervention no longer showed any signs of right heart strain, and dyspnea had disappeared completely. At a 4-month follow-up visit, the patient presented as completely symptom-free with a high quality of life. His ECG and echocardiography were normal and excluded recurrent right heart strain. Conclusions: Overall, the patient benefitted remarkably from endovascular mechanical thrombectomy, resulting in an almost complete resolution of electrocardiographic PE signs at the 4-month follow-up after exhibiting multiple typical electrocardiographic PE signs at time of diagnosis and initial electrocardiographic worsening 18 h post successful intervention.

Clinico-haematobiochemical and cardiac alterations in Trypanosoma evansi infected buffaloes of Andhra Pradesh, India.

The present research aimed to document the incidence, clinical signs, haematological, and serum biochemical alterations, as well as electrocardiography and echocardiography findings in 62 buffaloes (selected from a total of 240) infected with Trypanosoma evansi. The study spanned one year, from January 2022 to December 2022. Morphological identification of Trypanosoma evansi was done by the presence of a centrally positioned nucleus with a small sub-terminal kinetoplast at the posterior position through microscopic examination of Giemsa stained peripheral blood smears. The incidence of trypanosomosis were determined to be 26% (62/240) using stained blood smear examination and 41% (98/240) through polymerase chain reaction assay. Clinical signs exhibited by buffaloes with trypanosomosis included the lack of rumination (94%; 58/62), anorexia (90%; 56/62), emaciation (87%; 54/62), loss of milk yield (84%; 52/62), ocular discharges (82%; 51/62), depressed demeanour (81%; 50/62), sunken eye balls (61%; 38/62), fever (60%; 37/62), scleral congestion (56%; 35/62) and intermittent fever (42%; 26/62). Cardiovascular clinical findings in affected buffaloes included tachycardia (44%; 27/62), cardiac arrhythmia (24%; 15/62), cardiac murmurs (19%; 12/62) and muffled heart sounds (18%; 11/62). In the present study, buffaloes with trypanosomosis exhibited significant reduction in haemoglobin (p = 0.008), packed cell volume (p = 0.004), total erythrocyte count (p = 0.003), mean corpuscular volume (p = 0.042), total leucocyte count (p = 0.048) and absolute neutrophil count (p = 0.012); a significant increase in absolute eosinophil count (p = 0.011) and absolute monocyte count (p = 0.008) compared to the apparently healthy buffaloes. Additionally significant decrease in albumin (p = 0.001), A/G ratio (p = 0.007), calcium (p = 0.008), glucose (p = 0.007), phosphorous (p = 0.048), sodium (p = 0.008), potassium (p = 0.041) and chloride (p = 0.046) were observed in buffaloes with trypanosomosis compared to healthy ones. Buffaloes with trypanosomosis also showed significant increase in globulin (p = 0.004), aspartate aminotransferase (p = 0.008), bilirubin (p = 0.034), blood urea nitrogen (p = 0.071), creatinine (p = 0.029), cholesterol (p = 0.046), lactate dehydrogenase (p = 0.009), gamma-glutamyl transferase (p = 0.004) and creatine kinase-myoglobin binding levels (p = 0.005). Electrocardiography explorations in buffaloes with trypanosomosis revealed sinus tachycardia, low voltage QRS complex, ST segment elevation, wide QRS complex, sinus arrhythmia, sinus bradycardia, wandering pace maker, first degree atrio ventricular block, biphasic T wave and tall T wave. Echocardiography examination unveiled cardiac chamber dilatation, ventricular wall thickening and indications of pericarditis/cardiac tamponade. Necropsy was carried on the dead buffaloes during the study period disclosed severely congested blood vessels on epicardial surface, endocardial haemorrhages, and presence of pericardial fluid. Histopathological examination of the heart revealed hyaline degeneration, haemorrhages in the cardiac muscles and varying degrees of degenerative changes. Additionally, the pericardium displayed increased thickness due to presence of more elastic fibres, fibroblast cells in the myocardium, discontinuity of muscle layers, vascular congestion, perivascular mono nuclear cell infiltration and augmented thickness of the endocardium with fibroblast cell proliferation. The study's conclusion highlights cardiac alterations as secondary complications in buffaloes infected with Trypanosoma evansi. Further investigations are recommended to elucidate therapeutic modifications and refine the treatment paradigm.

Comparison of electrographic changes, clinical features and outcomes in different variants of Takotsubo syndrome

BackgroundDysfunction of the left ventricular (LV) apex (apical variant) is the most common form in Takotsubo syndrome (TS). Several less common non-apical variants have been described – mid-ventricular, basal and focal. We hypothesised that the clinical presentation, and electrocardiographic (ECG) findings may vary between apical and non-apical TS. MethodsWe prospectively identified 194 consecutive patients with TS presenting to Middlemore Hospital, Auckland and obtained clinical, echocardiography, coronary angiography, and long-term follow-up data. ECGs at admission and Day 1 were compared. ResultsOf 194 patients with TS, 168 (86.6%) had apical TS, and 26 (13.4%) non-apical TS (11 mid-ventricular TS, 5 basal TS, 10 focal TS). Apical TS patients had more significant LV systolic impairment (p = 0.001) and longer length of stay (p = 0.001). The extent of T-wave inversion (TWI) was similar for both groups on admission (p = 0.88). By Day 1 the extent of TWI was greater in apical TS group (median number of leads 5 vs. 1, p = 0.02). The change in QTc interval between admission and Day 1 was greater in apical TS group (29.7 ms vs. 2.77 ms, p < 0.001). Composite in-hospital complication rate was similar for both groups (13.7% vs. 15.4%, p = 0.77). ConclusionsCompared with non-apical variants, apical TS patients develop more extensive TWI and greater QT prolongation on ECG, and more significant LV systolic impairment, but in-hospital complications were similar. Clinicians should be aware that there is a sub-group of TS patients who have non-apical regional wall motion abnormalities and who don't develop ECG changes typical of the more common apical variant.

Electrocardiographic Findings in Pediatric MIS-C Patients

Electrocardiographic Findings in Pediatric MIS-C Patients

Assessment of Heart Rate Variability in Children with Mitral Valve Prolapse.

Mitral valve prolapse (MVP) is a heart valve anomaly with specific electrocardiographic findings and arrhythmia. A predominant sympathetic tone and diminished vagal activity have been reported especially in symptomatic MVP patients. In the current study, we aim to review heart rate variability (HRV) parameters of MVP children in order to determine if there is an impaired autonomic regulation. The data of children with MVP were retrospectively analyzed. Demographic characteristics, body mass index, symptomatology, MVP type and mitral regurgitation, MVP-related electrocardiographic changes, arrhythmia, and HRV parameters in 24-h Holter monitoring were recorded. HRV parameters of the control group were obtained from children applying for sport participation. Statistical significance limit was accepted as p < 0.05. 154 of the patients (74.8%) were girls, the median age was 13.58 ± 2.99years. While MVP patients had shorter PR intervals, those who had syncope had longer PR intervals. Short PR distance may be a feature of MVP, long PR distance may be a condition associated with syncope with the underlying paroxysmal atrioventricular block. Moreover, the minimum heart rate was significantly lower in the MVP group compared to the control and there were no significant differences in terms of remaining parameters. The number of low LF values was higher in MVP patients than the control. Comparing HRV values of groups by gender, we found that overall HRV parameters were lower in girls with MVP while minimum, maximum, and average heart rate were lower in boys with MVP. Impaired HRV associated with MVP could be age, gender, and symptom related. In addition, low LF may indicate impaired baroreflex sensitivity in MVP patients.

Echocardiographic and electrocardiographic findings in Irish Wolfhounds eating high-pulse or low-pulse diets.

Apparently healthy dogs of various breeds eating nontraditional, high-pulse diets can have larger left ventricular diameter, lower systolic function, and more ventricular premature complexes (VPCs) compared with dogs eating traditional, low-pulse diets. It is unknown whether Irish Wolfhounds eating high-pulse diets have similar cardiac abnormalities. To compare electrocardiographic and echocardiographic findings between Irish Wolfhounds eating high- or low-pulse diets. Ninety-seven Irish Wolfhounds. Retrospective study of Irish Wolfhounds that had echocardiography performed at dog shows between October 2018 and May 2021. Demographic information, echocardiographic measurements, cardiac rhythm (1-minute lead II rhythm strip), and main diet were recorded retrospectively. Diets were classified as high-pulse or low-pulse based on the presence and location of pulses (peas, lentils, chickpeas, or dry beans) on the ingredient list. Thirty-five of 97 Irish Wolfhounds (36%) were eating high-pulse diets and 62 of 97 (64%) were eating low-pulse diets. There were no significant differences between diet groups in echocardiographic measurements. A significantly higher percentage of dogs in the high-pulse diet group (6/35 [17%]) had VPCs compared with those in the low-pulse diet group (1/62 [2%]; effect size = 0.15 [95% confidence interval: 0.004-0.31]; P = .005). In this retrospective study of apparently healthy Irish Wolfhounds, high-pulse diets were associated with a higher prevalence of VPCs which could represent early cardiac abnormalities.

Cardiac Troponin I as an Early Prognostic Indicator in Asphyxiated Neonates

Background: Myocardial damage, estimated to occur in 28%–73% of asphyxiated neonates, 1 is a major cause of mortality in perinatal asphyxia, and survivors can show significant myocardial morbidity as well. 2 Study Setting and Design: This study is a hospital-based prospective cohort study, done at the pediatrics department of a tertiary care hospital in northern India, from December 2020 to June 2022. Materials and Methods: 40 asphyxiated neonates with an APGAR score of &lt;7 at 1 minute of life, as per the WHO–Neonatal Perinatal Database, were included in the study. They were graded as hypoxic ischemic encephalopathy (HIE) I (mild), II (moderate), and III (severe) based on Sarnat and Sarnat staging. The blood samples at 0 and 6 hours of life were taken for studying successive changes in the values of high-sensitivity cardiac troponin I (hs-cTnI) and creatinine phospho-kinase-myocardium-bound (CPK-MB). These were compared with various parameters such as electrocardiograph (ECG) findings, 2D-ECHO abnormalities, HIE severity, and outcome. Results: Among the two biomarkers that were assessed, hs-cTnI had the highest diagnostic value for detecting myocardial injury and was corelated with the severity of HIE and higher chances of death. Conclusion: The troponin I levels, in contrast to CPK-MB levels, were significantly associated with the outcome of the patient, implying that asphyxiated babies with elevated troponin I levels have a poorer prognosis and a higher mortality rate.

Stroke-heart Syndrome: Clinical Features, Electrocardiographic, and Imaging Findings in the Adult Population (P5-5.002)

Stroke-heart Syndrome: Clinical Features, Electrocardiographic, and Imaging Findings in the Adult Population (P5-5.002)

Tuberculous Pericarditis: A Case Report in South-east Nigeria

Tuberculosis is a chronic infection and a common cause of chronic pericardial effusion. Approximately 1-2% of patients with pulmonary tuberculosis (PTB) develop tuberculous pericarditis (TBP) and it is less common in the developed world than in developing countries where active tuberculosis is endemic. In these countries with high endemicity, TBP is the most common form of pericarditis and is often associated with HIV. The clinical picture is usually that of a chronic systemic illness in a patient with pericardial effusion. The index case is that of a 24 year old male, who had presented to our medical outpatient clinic with a history of cough and chest pain of 9 and 2 days duration respectively. Diagnosis was made following echocardiography, electrocardiography (ECG), Chest X-ray (CXR) and culture findings which showed features in keeping with tuberculous pericarditis. His clinical condition improved significantly following pericardiocentesis and TB treatment was subsequently instituted. He was discharged for outpatient follow-up 5 days after pericardiocentesis. TBP can be difficult to diagnose and often goes undetected especially in resource poor countries. Accurate and early diagnosis is important as it is a dangerous disease if left untreated.

Imaging Features of Arrhythmogenic Cardiomyopathies.

Arrhythmogenic cardiomyopathy (ACM) is a genetic disease characterized by replacement of ventricular myocardium with fibrofatty tissue, predisposing the patient to ventricular arrhythmias and/or sudden cardiac death. Most cases of ACM are associated with pathogenic variants in genes that encode desmosomal proteins, an important cell-to-cell adhesion complex present in both the heart and skin tissue. Although ACM was first described as a disease predominantly of the right ventricle, it is now acknowledged that it can also primarily involve the left ventricle or both ventricles. The original right-dominant phenotype is traditionally diagnosed using the 2010 task force criteria, a multifactorial algorithm divided into major and minor criteria consisting of structural criteria based on two-dimensional echocardiographic, cardiac MRI, or right ventricular angiographic findings; tissue characterization based on endomyocardial biopsy results; repolarization and depolarization abnormalities based on electrocardiographic findings; arrhythmic features; and family history. Shortfalls in the task force criteria due to the modern understanding of the disease have led to development of the Padua criteria, which include updated criteria for diagnosis of the right-dominant phenotype and new criteria for diagnosis of the left-predominant and biventricular phenotypes. In addition to incorporating cardiac MRI findings of ventricular dilatation, systolic dysfunction, and regional wall motion abnormalities, the new Padua criteria emphasize late gadolinium enhancement at cardiac MRI as a key feature in diagnosis and imaging-based tissue characterization. Conditions to consider in the differential diagnosis of the right-dominant phenotype include various other causes of right ventricular dilatation such as left-to-right shunts and variants of normal right ventricular anatomy that can be misinterpreted as abnormalities. The left-dominant phenotype can mimic myocarditis at imaging and clinical examination. Additional considerations for the differential diagnosis of ACM, particularly for the left-dominant phenotype, include sarcoidosis and dilated cardiomyopathy. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Novel electrocardiographic classification for stroke prediction in atrial fibrillation patients undergoing cardioversion

Abnormal conduction, structure and function of the atrial myocardium predispose to atrial fibrillation (AF) and stroke. Usefulness of electrocardiographic (ECG) indices in predicting stroke or systemic embolism (SSE) in patients undergoing cardioversion for AF remains unknown, especially in those at low estimated risk. To systematically evaluate the performance of various P-wave abnormalities (PWA) in predicting SSE 30 days after cardioversion (derivation cohort) and in the long-term (validation cohort). ECGs (n=1773) of AF patients undergoing an acute cardioversion were manually reviewed. The 30-day post-cardioversion data was used to derive a composite PWA variable. The ECG findings were validated using the long-term follow-up of patients with no anticoagulation. ECGs of 27 CAREBANK study patients with right atrial appendage biopsies were further analyzed for histopathological validation. During data derivation, the best performance was found using a combination of prolonged P-wave (≥180ms), deflected P-wave morphology in lead II, biphasic P-waves in inferior leads or increased P-terminal force (≥80mm*ms) as markers for extensive PWA. In the validation cohort 219/874 (25.1%) had extensive PWA. During a median follow-up of 4.9 years, there were 51 (5.8%) SSE in total. In a competing risk model PWA predicted SSE (aHR 2.1 per category, 95%CI 1.4-3.1, p<0.001). Area under the curve for SSE at 3 years were 0.77, 0.79 and 0.86 for PWA, CHA2DS2-VASc score or their combination, respectively. Histologically, extensive PWA was associated with interstitial fibrosis (p=0.033). Novel electrocardiographic PWA classification provided additional prognostic insight in AF patients.

Does black widow spider bite the heart?

BackgroundBlack widow spider (BWS) bites account for 0.5 % of global poisonings and 21 % of poisonings in North-East Iran. In addition to local reactions, systemic cardiovascular manifestations are likely to occur. ObjectiveThis study aims to present cases of patients who experienced cardiac symptoms after being envenomed by BWS. MethodsA descriptive retrospective cross-sectional evaluation was conducted on all patients who were bitten by a BWS in 2020 and presented with cardiac manifestations. They were referred to our tertiary pediatric cardiology center in Mashhad, Iran for evaluation. All accessible variables including history, physical examination, laboratory tests prioritizing cardiology, as well as electrocardiography and echocardiography findings were evaluated. ResultSix patients, ranging in age from 5.5 to 13 years old, were bitten by BWS. None of the patients had a past or drug history and were admitted due to pain complaints at various bite sites that radiated in different directions. Four patients showed signs of tachycardia and two showed hypertension, but no signs of infection were observed. Half of the patients experienced systemic complications. Upon arrival at the hospital, four patients showed elevated CKMB levels which decreased during their hospitalization. Troponin I and N-Terminal Pro B-type Natriuretic Peptide levels were high in all patients. One patient with unstable hemodynamics showed pro-BNP over 35,000. T wave inversion was observed in six patients, ST segment depression in three patients, and ST-segment elevation in one patient with overlap between them. ConclusionTaking notice of cardiovascular presentations after a BWS bite is considerable.

Accurate detection of lead malfunction from ECG-derived bipolar pacing stimulus amplitude

BackgroundOne common mode of lead failure is insulation breach, which may result in myopotential noise and device malfunction. “Pseudo-unipolarization” of bipolar pacing stimuli, as observed from a routine 12-lead electrocardiogram (ECG) due to stimulus current leak, has been observed with insulation breaches. ObjectiveWe sought to characterize this electrocardiographic finding to detect this type of lead malfunction. MethodsA total of 138 transvenous leads were analyzed, including 88 with known malfunction and 50 normal leads. The amplitude of a bipolar pacing stimulus on the ECG was recorded and compared with a control data set of newly implanted leads with bipolar stimuli normalized for output. ResultsThe malfunction group consisted of 61% right atrium and 39% right ventricle leads with mean pacing output of 2.74 V at 0.5 ms. There was a significant difference in ECG bipolar stimulus amplitudes at time of identification of failure (7.89 ± 7.56 mm/V; P < .001) compared with those of normal leads (0.86 ± 0.41 mm/V). Receiver operating characteristic curve for the prediction of lead malfunction based on absolute ECG amplitude displayed an area under the curve of 0.93 (95% CI, 0.891–0.969). When normalized for programmed stimulus output, a cutoff of 5 mm/V demonstrated a sensitivity of 91% and a specificity of 92% (area under the curve, 0.967; 95% CI, 0.938–0.996). ConclusionThe maximum amplitude of a bipolar pacing stimulus on the ECG is significantly lower in normal functioning leads compared with those with known malfunction. This simply derived variable demonstrated good accuracy at identifying lead failure due to insulation breach.