Abstract 2138: Predictive Value of the Index Arrhythmia in Long Term Programming of Implantable Cardioverter Defibrillators
Introduction: Programming of tachycardia detection and therapy based on features of the presenting ventricular tachycardia has been a common practice. Whether these index arrhythmias are reliable predictors of future arrhythmia events has not been studied. We compared the cycle length (CL) of index ventricular tachycardias to those observed during follow-up in patients after implantation of an Implantable Cardioverter Defibrillator (ICD) as secondary prevention.
Methods: 41 patients with a single or dual chamber ICD implanted after sustained monomorphic ventricular tachycardia (mVT) and a follow-up of at least 3 months were included in this retrospective analysis. CL of tachycardias recovered from device memory were compared to the CL of the index arrhythmia. Difference in CL of 50 msec or greater was considered significant. Morphologies of different mVTs were also compared in patients with at least two tachycardia episodes.
Results: A total of 490 spontaneous mVT episodes were analysed in 33 out of 41 patients during follow-up (3– 46 months; mean: 18 months). Tachycardias with significantly different CL when compared to the index mVT occured in 22 out of 33 (67%) patients. At least 2 different mVT morphologies were found in 21 out of 26 (81%) patients with at least two episodes of mVT.
Conclusion: These results suggest that the index arrhythmia has limited predictive value concerning subsequent spontaneous mVT episodes during long-term follow-up in patients with ICD implanted as a secondary prevention and support the concept of empirical device programming.