A 63-year-old man suffering from ischemic cardiomyopathy, old anterior myocardial infarction with a 48% LVEF, non-specific bundle branch block and 120-ms QRS duration, underwent negative electrophysiologic studies and programmed ventricular stimulation after a sudden episode of syncope. A Reveal DX Holter was implanted.
This patient suffered 3 syncopal episodes within 2 days, of which one was complicated by trauma. He triggered a recording for the 3rd episode only, labelled “symptom” on the episodes log. The first 2 syncopal episodes coincided with both episodes diagnosed as VT. The analysed episode, diagnosed as VT by the device, lasted over 1 min, at a mean rate of 200 bpm. It is noteworthy that the device programming is similar to that of an ICD, including 1 VT and 1 FVT zone, and a discrimination algorithm with sudden onset and stability operating like in an ICD. Sensing is also similar to that of an ICD, with a programmed post VS refractory period of 150 ms, and a 150 ms plateau from where sensitivity increases (the value decreases) to a highest programmable of 0.035 mV.
This was a Class 4D syncope (VT) in the ISSUE classification. The identification of a ventricular tachyarrhythmia in the wake of syncope is relatively rare after detailed investigations, including programmed ventricular stimulation. A depressed LVEF and the inducibility of a tachycardia are the 2 most reliable predictors of a ventricular arrhythmia causing syncope. Therefore, this patient’s presentation was relatively atypical. The confirmation of a ventricular arrhythmia causing syncope in this patient presenting with ischemic heart disease is a Class I indication for the implantation of an ICD. This clinical case highlights the high diagnostic value of this type of device, as well as its lack of therapeutic contribution. The diagnosis was made and the patient was appropriately treated after the spontaneous termination of a life-threatening tachyarrhythmia.
