3.1 Baseline patient characteristics and ILR implants in follow-up
The study included 348 patients who were implanted with an ILR for unexplained syncope. Follow-up data were available in 309 patients (88% out of total implanted patients), figure 1. The mean age was 59 years (range 4-93 years), 49% was female. The median number of syncope was 3 [1-3]. Baseline patient and electrocardiographic findings are summarized in table 1. Baseline conduction abnormalities on ECG were present in 13% of the patients. 8.7% had a first degree atrioventricular block, 2.3% left bundle branch block (LBBB), 7.4% right bundle branch block (RBBB), 2.3% bifascicular block and 0.6% had a trifascicular block. During work-up for syncope, all of the patients had a negative 24h Holter monitoring, and 46% underwent head up tilt testing, which was negative. Electrophysiologic (EP) study was performed in 59% of the patients (and negative), before implantation of the ILR. Numbers of patients implanted with different ILR models and according to different manufacturers are specified in figure 2. Two out of three patients (67%) received an ILR manufactured by Medtronic, 29% Abbott and 3% Biotronik.