Intrapericardial administration of anti-arrhythmic medications in patients with electrical storm

Introduction: Electrical storm (ES) is cardiac electrical instability characterized by recurrent episodes of ventricular tachyarrhythmias. ES is associated with increased mortality and morbidity, hence requires prompt intervention. Treatment of underlying etiology is of prime importance in termination of ES. Anti-arrhythmic medications serve as an adjunctive therapy in suppression of ES by reducing myocardial excitability. The anti-arrhythmic conventionally employed is amiodarone in combination with non-selective beta-blockers to reduce the adrenergic input to myocardium. However, anti-arrhythmics at increased concentrations can lead to adverse systemic effects including hemodynamic instability. Hypothesis: We hypothesize 1. The use of intravenous or oral anti-arrhythmic therapy for patients in electrical storm is limited by their toxicities and blood pressure lowering effect. Corollary 1. Injection of anti-arrhythmic medications into the pericardial space, an extra-vascular structure encasing the heart, provides an option for use of higher concentration of anti-arrhythmic while limiting systemic absorption. Corollary 2. The pericardial space has direct communication to the epicardium, the outer most layer of cardiac muscle, spatial proximity may allow for effective therapeutic options in electrical storm. We present experimental and clinical evidence in support of these hypothesis.