Foetal supraventricular tachycardia (SVT) can cause foetal hydrops and demise if untreated. Transplacental therapy often fails in severe SVT with foetal hydrops due to impaired placental drug transfer. In the present study, we report the first successful cardioversion of recalcitrant SVT in a hydropic foetus by intracardiac adenosine triphosphate (ATP) administration.

The majority of patients presenting to the emergency department with a stable, regular, monomorphic, wide complex tachycardia will be diagnosed with ventricular tachycardia, with a minority of these patients being diagnosed with supraventricular tachycardia (SVT) with aberrant conduction. Vagal maneuvers may be performed as a first-line treatment for these patients, primarily for the treatment of potential SVT with aberrant conduction.

Sickle cell disease is a hereditary haemoglobinopathy characterized by chronic haemolysis, vaso-occlusive events and multisystem involvement. Whereas haematological and pulmonary complications are well recognized, cardiac involvement - particularly arrhythmias - has recently emerged as an important contributor to morbidity and mortality. This review examines the spectrum of rhythm disturbances in this population based on recent clinical data. Electrocardiographic abnormalities are common, including corrected QT interval prolongation, sinus tachycardia and repolarization changes. Supraventricular and ventricular arrhythmias are increasingly reported, and may contribute to sudden cardiac death, particularly during acute vaso-occlusive events. Proposed mechanisms are multifactorial, involving myocardial ischaemia imbalance and inflammation. Despite growing awareness, the prognostic significance and optimal management of arrhythmias in sickle cell disease remain poorly defined. Further studies are needed to improve risk stratification and guide targeted preventive and therapeutic strategies.

In this paper, we present a powerful, compact electrocardiogram (ECG) classification algorithm for cardiac arrhythmia diagnosis that addresses the current reliance on deep learning and convolutional neural networks (CNNs) in ECG analysis. This work aims to reduce the demand for deep learning, which often requires extensive computational resources and large labeled datasets. Our approach introduces an artificial neural network (ANN) with a simple architecture combined with a compact, interpretable feature-engineering pipeline. A key contribution of this work is the incorporation of 17 engineered features that enable the extraction of critical patterns from raw ECG signals. By integrating mathematical transformations, signal processing methods, and data extraction algorithms, our model captures the morphological and physiological characteristics of ECG signals with high efficiency, without requiring deep learning. Our method demonstrates a similar performance to other state-of-the-art models in classifying five rhythm classes-normal sinus rhythm, sinus bradycardia, sinus tachycardia, ventricular flutter, and atrial fibrillation. Our algorithm achieved an accuracy of [Formula: see text] on the MIT-BIH and St. Petersburg INCART arrhythmia databases, with a Cohen's kappa of [Formula: see text] and a Matthews correlation coefficient of [Formula: see text]. The compactness of the model and its low inference latency on a standard CPU suggest that the approach is a promising candidate for deployment on resource-constrained platforms.

Takotsubo cardiomyopathy is a transient stress-induced cardiomyopathy typically triggered by emotional or physical stress. Since the emergence of coronavirus disease 2019 (COVID-19), several cardiovascular complications have been reported, including stress cardiomyopathy. Recurrent Takotsubo cardiomyopathy complicated by malignant ventricular arrhythmias and cardiogenic shock remains uncommon. A 73-year-old Hispanic female with a prior history of Takotsubo cardiomyopathy in 2013, subclinical hyperthyroidism, and hyperlipidemia presented with worsening malaise and subjective fever. She tested positive for COVID-19. Initial troponin was 0.070 ng/mL, with a peak value of 0.143 ng/mL. Pro-BNP (pro B-type natriuretic peptide) was markedly elevated at 11,250 pg/mL, reflecting significant myocardial wall stress. The initial electrocardiogram showed sinus rhythm with nonspecific T-wave abnormalities in leads III and aVF and a QTc interval of 452 ms. A repeat electrocardiogram six hours later revealed clear T-wave inversions in leads II, III, aVF, and V6. She was transferred to a tertiary care center, where she developed pulseless ventricular tachycardia due to an R-on-T phenomenon, requiring nine minutes of advanced cardiovascular life support. COVID-19 was considered the primary trigger after exclusion of alternative physical stressors. Coronary angiography demonstrated no obstructive coronary artery disease. Right heart catheterization revealed elevated filling pressures and low cardiac output consistent with cardiogenic shock. Transthoracic echocardiography showed an ejection fraction of 10% with apical ballooning typical of Takotsubo cardiomyopathy. Mechanical circulatory support with an intra-aortic balloon pump, inotropes, and vasopressors was required. The patient gradually improved; a repeat echocardiogram on day 9 demonstrated complete normalization of ejection fraction to 70%, cardiac magnetic resonance imaging revealed no late gadolinium enhancement, and sustained recovery was confirmed at outpatient follow-up with an ejection fraction of 60%-70%. Due to the malignant ventricular arrhythmia, a secondary prevention implantable cardioverter-defibrillator was placed. A follow-up electrocardiogram showed sinus rhythm with no ischemic changes, no Q waves, and a QTc of 428 ms. This case illustrates a recurrent Takotsubo episode temporally associated with COVID-19 infection and complicated by R-on-T ventricular tachycardia and cardiogenic shock. The prior normal myocardial perfusion study and full functional recovery support the diagnosis. A large national database study has shown that COVID-19 patients with stress cardiomyopathy have significantly higher mortality and complication rates. The role of subclinical hyperthyroidism as a potential sensitizer to catecholamine surges is explored. A recently published case of asymptomatic COVID-19 triggering recurrent Takotsubo highlights that the spectrum of this association ranges from subclinical infection to life-threatening presentations. COVID-19 infection was temporally associated with recurrent Takotsubo cardiomyopathy with life-threatening arrhythmias. Early recognition, aggressive hemodynamic support, and individualized decisions regarding implantable cardioverter-defibrillator placement are critical for favorable outcomes.