Complications and mortality of single versus dual chamber implantable cardioverter defibrillators

The implantable cardioverter defibrillators (ICDs) are increasingly being used as a treatment modality for life threatening tachyarrhythmia. The purpose of this study was to compare the frequency of complications and mortality between single-chamber and dual-chamber ICD implantation in Shahid Rajaie cardiovascular center.

Between January 2000 and December 2004, 234 patients received ICD by a percutaneous transvenous approach and were followed for 33 +/- 23 months. The cumulative incidence of complications was 9.4% over the follow-up period. There was no significant difference in overall complication rate between single chamber (VR) and dual chamber (DR) ICD groups in the follow-up period (P= 0.11). The risk of complications did not have any statistically significant difference in secondary versus primary prevention groups (P=0.06). The complications were not associated with the severity of left ventricular systolic dysfunction (P=0.16). The frequency of lead-related complications was higher in dual chamber ICDs in comparison with single chamber ICDs (P=0.02). There was no significant difference in mortality between different sex groups (P=0.37), different indications for ICD implantation (P=0.43) or between VR and DR ICD groups (P= 0.55). Predictors of mortality were NYHA class III or more (P<0.001), age >65 years (P=0.011) and LVEF<30% (P<0.001). The mortality in patients with CAD and DCM were significantly higher than those with other structural heart diseases (P=0.001).

Close monitoring of patients during the first 2 month after ICD implantation is recommended because the majority of complications occur early after the procedure.