[Differential diagnosis of tachycardic arrhythmias and its importance for therapeutic decisions]

The widespread application of catheter ablation techniques has significantly affected the meaning of non-invasive evaluation of both supraventricular and ventricular tachycardias. In patients with different forms of supraventricular tachycardias radiofrequency current ablation offers comparable high success rates. Therefore, since non-invasive and invasive classification of supraventricular tachycardias agree only in 80% of patients, the diagnosis based on non-invasive means may constitute a bias, but does not obviate the need for a scrutinized preablation electrophysiologic study to determine the very type of tachycardia. In contrast, in patients with ventricular tachycardias a manyfold of different therapies is available: antiarrhythmic drug medication, catheter ablation or surgical intervention including the implantation of programmable cardioverters/defibrillators. The selection of the optimal therapy, however, is predominantly dependent on the clinical presentation of tachycardia, on the type and the severity of the underlying structural heart disease and on the potential mechanism of tachycardia.