[Therapy with antiarrhythmic agents in cardiac insufficiency]. / Terapêutica com antidisrítmicos na insuficiência cardíaca.

The antiarrhythmic drugs characteristics are generally inadequate for the treatment of arrhythmics in heart failure. The pharmacokinetics and pharmaco dynamics of these drugs on heart failure are also altered conditioning its clinical use with a need for tayloring of therapeutics doses. Drug interaction and pro arrhythmic effects are also possible cause of difficulties. That must be considered according with the information about the pro arrhythmic effect of each drug. There is no consensus about how choose these drugs. The published therapeutic antiarrhythmic regimens are variable: monotherapy with amiodarone or propafenone and drug association regimens with type 1 drugs sometimes with beta-blockers. The efficacy of invasive or non invasive oriented drug therapy for the suppression of ventricular arrhythmics and reduction of mortality is generally accepted. When there is a great decrease of ejection fraction mexiletine and amiodarone are generally recommended. More recent information considers that treatment of "potentially malignant arrhythmias" are not justifiable.