Abstract
Background The ongoing technical advances in development of new implantable cardioverter defibrillator
(ICD) systems led some investigators to question the routine use of intraoperative
defibrillation testing (DT). Therefore, we evaluated retrospectively in a multicenter
study effectiveness, safety, and usefulness of intraoperative DT on unbiased large
patient population.
Methods Data from 4,572 consecutive patients undergoing any ICD intervention were retrospectively
analyzed. Besides efficacy of DT, risk factors for DT failure were identified in a
multiple logistic regression analysis.
Results Overall 5,483 shock data from 4,532 patients were available. Not tested for medical
reasons were 13.5%. DT-associated complications were not noted. Primary DT effectiveness
was 95.8%, whereas 4.2% were ineffective. Optimization (51.6% increase of DT energy,
10.1% subcutaneous lead array (SQ array), 2% generator exchange, 4.8% lead reposition,
9.3% lead exchange, and 22.2% change of shock parameters) led to successful DT in
152 patients (96.2%). Subanalyses and logistic regression identified implantation
of generator in any other position than left subpectoral, age, body mass index and
left ventricular ejection fraction as independent predictors for primary DT failure.
Conclusion The number of patients, including those undergoing generator exchange, system upgrade,
or system revision, with inappropriate intraoperative testshock is relatively high.
The results of recent prospective clinical trials can be extrapolated only on first
ICD implantations with high-energy generators. For patients undergoing subcutaneous
ICD implantation, right-sided implantation, patients with channelopathies and hypertrophic
cardiomyopathy, as well as for procedures on already implanted ICD systems, the intraoperative
DT might still be recommended.
Keywords
arrhythmia - outcome - cardiology/cardiologist - heart - surgery - defibrillation
test - ICD
