Procedure-related Complications
The incidence of procedure-related complications was observed more frequently in the Outer-Cath group (4.7 vs 31.3%; P=0.002, Table 3). A major cause of procedure-related complications was mechanical injury of the CS due to the repeat cannulations of the Outer-Cath into the CS, which was observed in 5 patients (15.6%) of the Outer-Cath group. As a result of CS perforation, 2 patients required abandonment of the LV-LP. Figure 3 demonstrates a case with CS perforation due to repeated cannulations of an Outer-Cath into the CS trunk. However, LV-LP was finally achieved by using an Inner-Cath alone without any problems. In addition, LV lead dislodgement was observed in one patient (2.4%) from the Outer-Cath group a month after the procedure.