Atrial tachycardia associated with a tachycardia-induced cardiomyopathy in a patient with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multiple organ systems. Cardiovascular involvement in SLE is well described in the literature. Cardiac arrhythmias associated with SLE include sinus tachycardia, atrial fibrillation, and atrial ectopy or atrial tachycardia. In this report, we present the case of a patient with SLE who was found to have focal atrial tachycardia that mimicked sinus tachycardia on a 12-lead electrocardiogram (ECG). She was inappropriately treated as a case of sinus tachycardia initially. But she did not respond to the treatment and developed tachycardia-induced cardiomyopathy despite being on antiarrhythmic medications. She subsequently underwent successful radiofrequency catheter ablation and her left ventricular ejection fraction (LVEF) recovered within three months after the ablation

Comparing sensitivity and specificity of pacemaker ID application and cardiac rhythm management device-finder application in identifying cardiac implantable electronic device manufacturer using chest radiograph - An observational study

Background: Smartphone-based applications to identify cardiac implantable electronic devices (CIED) are extremely useful in circumstances, where urgent device interrogation is needed, and a device identification card is not available. Few studies have provided insights regarding the utility of these applications. We have studied two widely available applications i.e., Pacemaker ID app (PMIDa) or Cardiac Rhythm Management Device-Finder (CRMD-f) to identify device manufacturers in CIEDs.Methods: 547 patients who underwent CIED implantation from the year 2016-2020 in our institute were enrolled. There were 438 Medtronic and 109 St. Jude\u27s devices. All chest radiographs were de-identified and resized into 225*225 pixels focusing on the CIED. PMIDa and CRMD-f applications were used to identify the CIED. Accuracy, sensitivity, specificity, negative predictive value, and positive predictive value for both applications were calculated and compared.Results: Overall, CRMD-f application has higher specificity (93.58 vs. 82.5%) but lower sensitivity (53.6 vs. 55%) than PMIDa. The accuracy of both applications was comparable (61.6% vs. 60.5%). Accuracy varied with CIED model and type tested, and radiograph projection used. Accuracy is greatest with Cardiac-Resynchronization-Therapy (CRT) devices for both applications, followed by a single lead pacemaker.Conclusion: CRMD-f has higher accuracy and specificity for CIED manufacturer identification. Both PMIDa and CRMD-f are specific tools to identify CIED but have low sensitivity

Structural and functional properties of subsidiary atrial pacemakers in a goat model of sinus node disease

Background: The sinoatrial/sinus node (SAN) is the primary pacemaker of the heart. In humans, SAN is surrounded by the paranodal area (PNA). Although the PNA function remains debated, it is thought to act as a subsidiary atrial pacemaker (SAP) tissue and become the dominant pacemaker in the setting of sinus node disease (SND). Large animal models of SND allow characterization of SAP, which might be a target for novel treatment strategies for SAN diseases.Methods: A goat model of SND was developed (n = 10) by epicardially ablating the SAN and validated by mapping of emergent SAP locations through an ablation catheter and surface electrocardiogram (ECG). Structural characterization of the goat SAN and SAP was assessed by histology and immunofluorescence techniques.Results: When the SAN was ablated, SAPs featured a shortened atrioventricular conduction, consistent with the location in proximity of atrioventricular junction. SAP recovery time showed significant prolongation compared to the SAN recovery time, followed by a decrease over a follow-up of 4 weeks. Like the SAN tissue, the SAP expressed the main isoform of pacemaker hyperpolarization-activated cyclic nucleotide-gated channel 4 (HCN4) and Na+/Ca2+ exchanger 1 (NCX1) and no high conductance connexin 43 (Cx43). Structural characterization of the right atrium (RA) revealed that the SAN was located at the earliest activation [i.e., at the junction of the superior vena cava (SVC) with the RA] and was surrounded by the paranodal-like tissue, extending down to the inferior vena cava (IVC). Emerged SAPs were localized close to the IVC and within the thick band of the atrial muscle known as the crista terminalis (CT).Conclusions: SAN ablation resulted in the generation of chronic SAP activity in 60% of treated animals. SAP displayed development over time and was located within the previously discovered PNA in humans, suggesting its role as dominant pacemaker in SND. Therefore, SAP in goat constitutes a promising stable target for electrophysiological modification to construct a fully functioning pacemaker

Cardiovascular fellow-in-training feedback on virtual and simulator-based learning experience during Covid-19 pandemic in a low to middle income country - A cross-sectional study

Background: COVID-19 pandemic has introduced us to a greater need of virtual learning platforms and has resulted in less clinical exposure for fellows-in-training. Virtual and simulator-based learning is not widely available in LMIC. It is imperative to analyze feedback of CV fellow-in-training regarding this mode of learning before large scale implementation.Methodology: This was an observational study conducted between July-August 2020. A multicentered survey was conducted. Survey questionnaire was disseminated to FIT (fellow-in-training) via Google Forms. The questionnaire contained a total of 24 questions about virtual and simulator-based learning during the pandemic.Results: A total of 68 FIT responded to the survey. The mean age was 29.9 years. There were 37% females and 63% males. Majority (75%) agreed that it was easier for them to reach for online sessions than physical sessions. 60% FIT were confident in asking questions or giving comments during the online sessions. 57.4% FIT felt it easier to go through cardiovascular imaging/illustrations via online platforms. 50% (34) were confident that if online sessions had to continue, they would have enough academic learning before they graduated from the program and 54.4% (37) wanted online sessions to continue even beyond the pandemic days. 37.5% (18 out of 48) agreed that the simulator-based teaching was helping them practice skills in times of less clinical exposure.Conclusion: COVID-19 pandemic has significantly impacted cardiovascular FIT learning curve because of less hands-on and lack of physical teaching sessions. LMIC have lack of robust e-learning platforms. Virtual learning is convenient for academic learning with growing acceptance amongst fellows. FIT from LMIC are less acquaint to simulator-based teaching and there is a need to invest in simulator-based cardiovascular teaching in LMIC

Loperamide-induced cardiotoxicity: A case overlooked?

A young man presented to the emergency department with seizures and recurrent episodes of polymorphic ventricular tachycardia (PMVT)/torsades de pointes (TdP) requiring cardioversion and administration of intravenous magnesium. A battery of tests performed to identify a cause for his arrhythmias and seizures were all normal. A revisit of history with family revealed he had consumed over 100 tablets/day of loperamide for the past 1 year. A prolonged QT interval on his ECG raised concerns for long QT syndrome (LQTS) (congenital or acquired). Our patient was suspected to have loperamide-induced cardiotoxicity. TdP is a specific PMVT that occurs with a prolonged QT interval and is usually drug-induced. Less frequently, congenital LQTS may be implicated. With supportive care, including mechanical ventilation, vasopressors and temporary transvenous overdrive pacing, our patient recovered completely. We describe the importance of a systematic and time-sensitive approach to diagnosing critical illness. Loperamide overdose may cause QT prolongation, life-threatening arrhythmias/cardiogenic shock, or cardiac arrest. Seizures/epilepsy may also be a manifestation in young patients. There is a substantial need to revisit the safety of over-the-counter medications and increasing awareness of manifestations of drug overdose

Validation of a prediction score model to distinguish acute coronary syndromes from other conditions causing raised cardiac troponin T levels

Objective: Serum cardiac troponins can be elevated in acute coronary syndromes (ACS) and other non-ACS conditions. We investigated the usefulness of a prediction score model comprising clinical variables to distinguish patients with ACS from other non-ACS conditions. Methods: Two independent, non-randomized observational cohorts (groups 1 and 2) were examined, comprising consecutive patients who were admitted to a university teaching hospital and found to have a raised serum troponin T level (>=0.01 [mu]g/l). The international definition was used to confirm acute myocardial infarction. Multivariate logistic regression identified clinical variables in the first cohort, which were used to construct a score model for distinguishing between ACS and non-ACS, and this score was re-evaluated in the second cohort. Results: Of the 313 patients in group 1, a score model was formulated using logarithm troponin T, ischaemic chest pain, ST depression and atrial fibrillation or flutter. Using a score of more than or equal to 1.5, sensitivity and specificity for predicting non-ACS were 0.81 and 0.84. The area under the curve was 0.900 (95% confidence interval 0.867-0.934). Sensitivity and specificity for predicting non-ACS among the 341 patients in group 2 using the same model and a score of more than or equal to 1.5 were 0.76 and 0.89, respectively, and the area under the curve was 0.918 (confidence interval 0.887-0.945). Conclusion: A prediction score model using simple clinical variables has been validated, and this can help clinicians in distinguishing patients with ACS from other non-ACS conditions

Clinical characteristics and prognostic factors of atrial fibrillation at a tertiary center of Pakistan – from a South-Asian perspective – A cross-sectional study

Background: There is lack of large data from South-Asian region on atrial fibrillation and it is imperative that clinical presentation, prognostic factors, management pursued, and outcomes are known for this part of the world. Once collective evidence for the region is known, region-specific guidelines can be laid forward. Objectives: To evaluate clinical characteristics and prognostic factors of atrial fibrillation at a tertiary care center of Pakistan. Methods: This was a retrospective study conducted at a tertiary care center of Pakistan. Period of study ranged from July-December 2018. All hospitalized patients who were admitted with atrial fibrillation as a primary or associated diagnosis were enrolled. Results: A total of 636 patients were enrolled. The mean age was 68.5 ± 12 years and 49.5% (315) were male. 90.6% of the patients were admitted via emergency room. Majority (59.9%) had previously known AF and 40% developed new-onset AF during the hospital stay. Hypertension was the most common co-morbid condition (85.4%) followed by Diabetes Mellitus (40.1%). At least 9% had rheumatic heart disease. The median CHA2DS2VASc and HASBLED scores were 4 and 2 respectively. More than one-third of patients had sepsis as a primary diagnosis (36.8%). The in-hospital mortality of patients with atrial fibrillation was 6.7%. Patients with new-onset AF had higher mortality. Sepsis and stroke were independently associated with a higher mortality. There was no significant difference in median CHA2DS2VASc and HASBLED scores for patients with new-onset and previously known AF. On discharge, 83% of the eligible patients received oral anticoagulation. Conclusion: There was higher prevalence of chronic co-morbid conditions in the studied population leading to a higher CHA2DS2VASC Score. Sepsis and stroke were independently associated with higher in-hospital mortality