Case Presentation: A 25-year-old female with no significant medical history presented with recurrent syncope, reporting no use of medications, stimulants, alcohol, or illicit drugs, and no family history of cardiomyopathies or sudden cardiac death. Her first syncopal episode in December 2020 occurred suddenly, without prodromal symptoms, followed by two more episodes in 2021 and 2022, accompanied by palpitations, dizziness, confusion, and urinary incontinence. Emergency evaluations, including physical exams, electrocardiograms, and lab tests, were unremarkable. Cardiologic workup, including a 24-hour Holter monitor, revealed premature ventricular complex trigeminy and a transthoracic echocardiogram showed normal left and right ventricular size and function, with an ejection fraction of 65% and no significant valve disease. An electrophysiology study revealed baseline intervals, with no evidence of accessory pathways or inducibility into supraventricular or ventricular tachycardia. A loop recorder was implanted for further monitoring, and three months later, a fourth syncopal episode led to the detection of Torsade’s de Pointes and ventricular fibrillation, prompting ICD placement. Genetic testing revealed variants in PDLIM3 and SLC2A1. Follow-up evaluations showed recurrent non-sustained ventricular tachycardia, requiring adjustments in antiarrhythmic therapy. The patient’s prognosis improved with ongoing care.
Discussion: This case underscores the diagnostic challenges of idiopathic Torsades de Pointes (TdP) in patients without structural heart abnormalities. Short-coupled premature ventricular complexes (PVCs), often originating from the Purkinje fibers or specific ventricular regions, were identified as key triggers for polymorphic ventricular tachycardia (VT) and subsequent ventricular fibrillation (VF). These PVCs disrupt the heart’s electrical system through mechanisms like the R-on-T phenomenon, facilitating arrhythmias. Effective treatment involves identifying and managing these PVCs with antiarrhythmic therapy and implantable cardioverter defibrillator (ICD) placement to prevent sudden cardiac death. Genetic testing revealed variants in the PDLIM3 and SLC2A1 genes, though their roles in arrhythmogenesis remain unclear. PDLIM3, involved in sarcomere structure, may indirectly contribute to arrhythmias through cardiac remodeling, while SLC2A1, related to glucose transport, lacks evidence linking it to arrhythmias. Further research is needed to explore the potential connections between these genetic variants and arrhythmogenic disorders.
Conclusions: In conclusion, this case report enhances the understanding of idiopathic Torsade de Pointes (TdP) and underscores the necessity of a comprehensive diagnostic evaluation in patients with unexplained recurrent syncope. The case illustrates the diagnostic challenges posed by idiopathic TdP, highlighting the importance of considering arrhythmic causes even when initial cardiac assessments are unremarkable. The identification of TdP in this patient emphasizes the need for continuous cardiac monitoring and the potential utility of genetic testing to uncover underlying triggers. Effective management of idiopathic TdP often requires a combination of preventative measures, such as ICD implantation and antiarrhythmic therapy. Further investigation into the genetic predispositions to this life-threatening arrhythmia remains essential.
