Fosphenytoin for control of electrical storm in acute myocardial infarction and Purkinje fiber-mediated arrhythmias

Focus on malignant ventricular premature contractions

Premature ventricular contractions (PVCs) are common. Although often benign, they can also be associated with increased morbidity and mortality. The aim of this review was to assess the risk evaluation of PVCs in patients with or without structural heart disease and discuss the management of this arrhythmia. Reports published in English were searched in PubMed with the following search terms: premature ventricular contraction, ectopic ventricular beat, ventricular extrasystole, antiarrhythmic drugs, ablation, ventricular arrhythmia, ventricular tachycardia, ventricular fibrillation and torsade de pointe. This analysis suggests that all patients with frequent PVCs should be assessed for PVC burden, symptom status and the presence of structural heart disease. PVCs in patients with structurally normal hearts was once considered a benign phenomenon. Uncommonly, PVCs may provoke life-threatening arrhythmias. Ventricular fibrillation is the initial mode of malignant rapid ventricular arrhythmias (MRVAs). Patients with malignant PVC and PVC burden >10% are at increased risk of MRVA in case of myocardial infarction and heart failure. MRVA is the primary cause of sudden cardiac death in patients with and without structural heart disease. Therapeutic options include medical therapy and catheter ablation, the latter more effective and potentially curable, particularly in patients with left ventricular dysfunction. The timely recognition and effective treatment of malignant PVCs in symptomatic patients with underling cardiomyopathy are mandatory to initiate early therapies before the occurrence of adverse clinical outcomes and to improve the long-term prognosis.

Use of supra-therapeutic phenytoin for management of ventricular arrhythmias in children: Case series and literature review

Phenytoin is a versatile drug with utility in neurological, dermatological, and even cardiac disease processes. Though phenytoin is widely available due to its excellent anti-epileptic properties, it is now rarely used as an antiarrhythmic. Phenytoin has well-studied sodium-channel blocking abilities which can be taken advantage of to treat ventricular arrhythmias. Thus, it should remain in the arsenal of antiarrhythmics for any electrophysiologist. We present two cases of intractable ventricular arrhythmia in children that were controlled with phenytoin at supra-therapeutic serum levels, preventing the need for heart transplantation.