'True' atrial tachycardia.

Atrial tachycardia is a rare form of supraventricular tachycardia, accounting for about 10-15% of patients presenting to experienced arrhythmia centres for radiofrequency catheter ablation. The mechanism may be either focal due to increased or abnormal automaticity or triggered activity, or macro re-entrant. When incessant tachycardia is present, tachycardiomyopathy may develop. The efficacy of antiarrhythmic drugs for long-term management of atrial tachycardia is poorly defined, but is probably limited. Class IC or class I agents may be used in re-entrant atrial tachycardia, and verapamil, beta-blockers or class IC agents in the focal type. If these drugs fail, amiodarone may be tried. Experience with radiofrequency catheter ablation to cure atrial tachycardia is limited, but results are very promising with success rates between 80% and 95%, and an acceptably low recurrence and complication rate. Thus, it is likely that, with more experience, radiofrequency catheter ablation will become therapy of first choice for atrial tachycardia when this arrhythmia is not easily and effectively controlled by drugs.