14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-178

Oral antiarrhythmic drugs for the termination of paroxysmal supraventricular reentrant tachycardia

Paolo Alboni, Corrado Tomasi*, Carlo Menozzi*, Nicola Bottoni*, Nelly Paparella, Giuseppe Fuca, Riccardo Cappato**, Michele Brignole***.
Division of Cardiology, Ospedale Civile, Cento, *Section of Arrhythmology, Department of Cardiology, Ospedale S. Maria Nuova, Reggio Emilia, Italy, **Medizinische Abteilung, AK St. George, Hamburg, Germany, ***Section of Arrhythmology, Department of Cardiology, Ospedali Riuniti, Lavagna, Italy

In patients with frequent episodes of reentrant supraventricular tachycardia (SVT), long-term oral prophylaxis with antiarrhythmic drugs treatment has long been used in order to prevent clinical recurrences. However, the daily intake of antiarrhythmic agents, sometimes in multiple doses or drug combinations, together with the risk of drug-related adverse effects are recognized disadvantages of long-term prophylactic therapy. In addition, despite optimal drug administration and compliance, relapses are not infrequent in these patients¹. Recently, radiofrequency catheter ablation has been introduced in clinical practice and proven to be a highly effective curative therapy for SVT. However, major complications have been reported in up to 3% of patients undergoing this therapy².

Not infrequently, patients with SVT may present with episodes which are rare and well-tolerated, but long enough to require emergency room admission. In these patients, long-term oral prophylaxis or cateter ablation may not represent the most appropriate first-line treatment. Rather, an optimal approach in this group of patients might be an “episodic treatment” consisting of a single-dose oral ingestion of an antiarrhythmic drug at the time and site of arrhythmia onset^3,4. This type of treatment has already been investigated in patients with paroxysmal atrial fibrillation^5-8, but not yet in patients with paroxysmal SVT, except for subgroups with frequent episodes^9-11.

The aims of this study were to verify: 1) the efficacy of antiarrhythmic drugs as an acute oral dose to terminate SVT in patients with infrequent, long-lasting and well tolerated episodes of this tachycardia and 2) the out-of-hospital feasibility and safety of this treatment. To this purpose, we have utilized in a controlled design oral flecainide (F) and oral diltiazem plus propranolol (D/P). These drugs were chosen because of the encouraging results reported in the literature^10,11.