The aim of this multicentre study, carried out by the Italian Study Group on the Electrophysiology of Arrhythmias (GISEA) in 60 Italian Cardiology Centres on 260 patients, was to assess the efficacy and the safety of
flecainide in the treatment of stable hyperkinetic ventricular arrhythmias (greater than 100
ventricular ectopic beats/hour per day). The stability of the
arrhythmia was verified using 24 hour Holter recordings allowing for a spontaneous variability of less than 20%. All the patients belonged to class NYHA I or II.
Flecainide was administered in 2 x 100 mg/day doses and if the efficacy criteria, checked by the Holter on the 6th day, were not met the dose was increased to 2 x 150 mg/day. After a further Holter recording on the 11th day,
therapy continued until the 31st day when the final recordings were carried out. The study protocol was completed by 249/260 pts. (95.7%). Due to violation of the protocol which included lack of basal stability of the
arrhythmia 69/249 pts. (28%) were excluded. The 69 excluded patients were not considered for the efficacy evaluation, but entered for safety considerations. Only 16/180 (8%) of the qualified pts. were drop-outs. In the remaining 164 patients considered in the final evaluation,
flecainide proved to be effective in 122 patients (74%) with a greater than 80% reduction of
ventricular ectopic beats. In 118/131 patients (90%) there was a greater than 75% reduction in the couples and suppression of non-sustained
ventricular tachycardia. The
flecainide plasma levels were, on average, within the therapeutic range and could be correlated to dose level. The total incidence of adverse effects was 15% and the most frequent extracardiac ones were of a neurologic type. Proarrhythmic effects were observed in only 3/249 patients. This multicenter study in pts. with greater than 2400
ventricular ectopic beats/day confirms that
flecainide is effective in the treatment of hyperkinetic ventricular arrhythmias including complex ones and that it is well tolerated in patients in a good NYHA functional class. Moreover this study emphasizes the serious problem of the individual variability of
ventricular ectopic beats which requires the application of rigorous selection criteria for the correct execution of the trial as was done in this study.