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Shock Coordinated with High Power of Morphology Electrogram Improves Defibrillation Success in Patients with Implantable Cardioverter Defibrillators
Author(s) -
BERKOWITSCH ALEXANDER,
CARLSSON JOERG,
ERDOGAN ALI,
GUETTLER NORBERT,
NEUZNER JOERG,
PITSCHNER HEINZ F.
Publication year - 2002
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1046/j.1460-9592.2002.01293.x
Subject(s) - medicine , defibrillation , defibrillation threshold , cardiology , shock (circulatory) , depolarization , implantable cardioverter defibrillator , ventricular fibrillation
BERKOWITSCH, A., et al. : Shock Coordinated with High Power of Morphology Electrogram Improves Defibrillation Success in Patients with Implantable Cardioverter Defibrillators. Animal studies have suggested that the success of defibrillation may depend on the properties of VF waveform obtained from the morphology electrogram (ME) at the time of the shock. The reliable identification of depolarization events in the fibrillatory signal can be achieved using adaptive estimation of the instantaneous signal power (P). The aim of this study was to investigate if a high P of the ME (P ME ) was related to ventricular DFT and if the upslope in ME can be associated with the depolarization event. A total of 575 VF (mean duration 10 s) episodes recorded and stored during ICD implantation in 77 patients with ventricular arrhythmias were used for analysis. The DFT was defined using a double step‐down test. The values of P ME immediately before pulse delivery (P shock ) and shock outcomes were registered. The differences between P shock of successful and failed defibrillation were tested with the Mann‐Whitney U test. The relationship between individual medians of P shock (P med ) and DFT was analyzed using the Kruskall‐Wallis H‐test. The coincidence between identified depolarization and upslope in ME was tested using the chi‐square test. A P value of 0.05 was set for an error probability. The P shock in case of failed defibrillation was significantly lower than P shock in successful cases by the pulses of any strength (P < 0.001). The test revealed a significant inverse correlation between P med and DFT with P < 0.001. The depolarization corresponded to the upslope of ME in 85% of cases. This study demonstrated that a high value of instantaneous power of ME indicates the optimal time for shock delivery. The implementation of this algorithm in ICDs may improve the defibrillation efficacy.