[What is left of invasive electrophysiological explorations?]

After a golden period during which invasive electrophysiological investigations improved our understanding of the physiopathology of cardiac arrhythmias the clinical indications have now become more restricted. In the investigation of syncope, electrophysiological studies are only envisaged when the diagnosis is uncertain after clinical examination, resting ECG and non-invasive investigations. Holter monitoring in particular. Three types of arrhythmia may confirm our positive diagnostic criteria: sinoatrial block in patients with a sinus node recovery time greater than 1,000 ms uninfluenced by atropine atrioventricular block in patients with distal conduction defects during sustained atrial pacing, if necessary after injection of ajmaline: ventricular tachycardia in patients sustained monomorphic VT induced by 2 or 3 extrastimuli. The selection of the clinical indications has significantly improved the diagnostic value of electrophysiological investigations. The negativity of a strictly performed protocol, even though not giving a precise diagnosis of a syncopal episode, does provide reassuring prognostic information. In VT, electrophysiological studies may also be used to evaluate the secondary prognosis but with a diagnostic value no greater than that of non-invasive investigations. Programmed ventricular stimulation is not systematic for guiding antiarrhythmic therapy in France. Reserved for recurrent VT, electrophysiological studies are of additional value in the adaptation of treatment and improve the secondary prognosis.