Insights into the mechanism of idiopathic left ventricular tachycardia: a case report and literature review

Belhassen Tachycardia in a Pediatric Patient: A Simulation for Pediatric Emergency Medicine Fellows

Ventricular tachycardia in pediatric emergency department patients is a high-risk, low-frequency event well suited for education through simulation. This technical report describes a simulation-based curriculum for Pediatric Emergency Medicine fellows and senior residents involving the evaluation and management of a 10-year-old female presenting with palpitations who is ultimately diagnosed with Belhassen tachycardia. The curriculum highlights the features that differentiate Belhassen tachycardia (idiopathic left posterior fascicular ventricular tachycardia) from supraventricular or other tachycardias, building upon foundational pediatric resuscitation skills and Pediatric Advanced Life Support (PALS) algorithms for advanced learners.

Ventricular Arrhythmias in the Patient with a Structurally Normal Heart

Ventricular arrhythmias (VAs) are among the most common cardiac rhythm disturbances encountered in clinical practice. Patients presenting with frequent ventricular ectopy or sustained ventricular tachycardia represent a challenging and worrisome clinical scenario for many practitioners because of concerning symptoms, frequent associated acute hemodynamic compromise, and the adverse prognostic implications inherent to these cases. While an underlying structural or functional cardiac abnormality, metabolic derangement, or medication toxicity is often readily apparent, many patients have no obvious underlying condition, despite a comprehensive diagnostic evaluation. Such patients are diagnosed as having an idiopathic VA, which is a label with specific implications regarding arrhythmia origin, prognosis, and potential for pharmacologic and invasive management. Further, a subset of patients with otherwise benign idiopathic ventricular ectopy can present with polymorphic ventricular tachycardia and ventricular fibrillation, adding a layer of complexity to a clinical syndrome previously felt to have a benign clinical course. Thus, this review seeks to highlight the most common types of idiopathic VAs with a focus on their prognostic implications, underlying electrophysiologic mechanisms, unique electrocardiographic signatures, and considerations for invasive electrophysiologic study and catheter ablation. We further address some of the data regarding idiopathic ventricular fibrillation with respect to the heterogeneous nature of this diagnosis.

[Fascicular ventricular tachycardia in a 49-year-old patient]

We report a 49-year-old patient who presented with tachycardia in our emergency room. The 12-lead ECG showed a wide complex tachycardia with a heart rate of 234 beats per minute. After structural heart disease was excluded via echocardiography, coronary angiography and magnetic resonance imaging, an electrophysiological study was performed. During programmed ventricular stimulation, a fascicular tachycardia was induced, which was successfully treated by radiofrequency ablation. Fascicular ventricular tachycardia is a rare tachycardia that occurs in patients without structural heart disease. Radiofrequency ablation can be performed safely and shows a high success rate. Differential diagnoses of fascicular ventricular tachycardias are substrate-based ventricular tachycardia and supraventricular tachycardia.