[Modern therapy of paroxysmal supraventricular tachycardia]

Paroxysmal supraventricular tachycardia (SVT) may have numerous electro-physiologic mechanisms. The most common type of SVT is AV-nodal reentry tachycardia (60%) followed by the bypass tract-mediated SVT (preexcitation. 30%) and a smaller group (10%) comprising paroxysmal atrial flutter or fibrillation and atrial ectopic tachycardia. In persons with otherwise normal hearts symptoms are usually mild and include palpitations or an uneasy feeling in the chest. But some describe precordial pain. Weakness, dizziness, nausea, vomiting, and even syncope. Whenever possible a 12-lead-ECG during an episode of SVT should be obtained. If not possible the use of several Holter-ECG or of an event-recorder may be helpful. Conversion of a SVT can be accomplished by vagal maneuvers or intravenous adenosine (6-18 mg bolus injection). Further diagnostic procedures should prove or rule out a significant structural heart disease. Therapeutic options (expectative, pharmacological prophylaxis, invasive electrophysiologic testing and catheter-mediated modification or ablation) are chosen according to the objective threat (e.g. ventricular fibrillation due to 1:1 conducted atrial fibrillation in a preexcitation syndrome) and the subjective complaints. Definitive healing of the AV-nodal reentry tachycardia and the bypass tract-mediated SVT can be achieved by use of catheter-mediated modification or ablation in 95 to nearly 100%.