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Prospective Randomized Comparison of Two Defibrillation Safety Margins in Unipolar, Active Pectoral Defibrillator Therapy
Author(s) -
CARLSSON JOERG,
SCHULTE BRITTA,
ERDOGAN ALI,
SPERZEL JOHANNES,
GÜTTLER NORBERT,
SCHWARZ TORSTEN,
PITSCHNER HEINZF.,
NEUZNER JOERG
Publication year - 2003
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.1460-9592.2003.00102.x
Subject(s) - defibrillation , medicine , ventricular fibrillation , defibrillation threshold , cardiology , population , implantable cardioverter defibrillator , environmental health
CARLSSON, J., et al .: Prospective Randomized Comparison of Two Defibrillation Safety Margins in Unipolar, Active Pectoral Defibrillator Therapy.Various techniques are used to establish defibrillation efficacy and to evaluate defibrillation safety margins in patients with an ICD. In daily practice a safety margin of 10 J is generally accepted. However, this is based on old clinical data and there are no data on safety margins using current ICD technology with unipolar, active pectoral defibrillators. Therefore, a randomized study was performed to test if the likelihood of successful defibrillation at defibrillation energy requirement (DER) +5 J and +10 J is equivalent. Ninety‐six patients (86 men; age61.0 ± 10.3years; ejection fraction0.341 ± 0.132; coronary artery disease [n = 65],dilated cardiomyopathy [n = 18], other [n = 13]) underwent implantation of an active pectoral ICD system with unidirectional current pathway and a truncated, fixed tilt biphasic shock waveform. The defibrillation energy requirement (DER) was determined with the use of a step‐down protocol (delivered energy 15, 10, 8, 6, 4, 3, 2 J). The patients were then randomized to three inductions of ventricular fibrillation at implantation and three at predischarge testing with shock strengths programmed to DER + 5 J at implantation and + 10 J at predischarge testing or vice versa. The mean DER in the total study population was 7.88 ± 2.96 J . The number of defibrillation attempts was 288 for +5 J and 288 for +10 J. The rate of successful defibrillation was 94.1% (DER + 5 J) and 98.9% (DER + 10 J; P < 0.01 for equivalence). Charge times for DER + 5 J were significantly shorter than for DER + 10 J ( 3.65 ± 1.14 vs 5.45 ± 1.47 s; P < 0.001 ). A defibrillation safety margin of DER + 5 J is associated with a defibrillation probability equal to the standard DER + 10 J. In patients in whom short charge times are critical for avoidance of syncope, a safety margin of DER + 5 J seems clinically safe for programming of the first shock energy. (PACE 2003; 26[Pt. I]:613–618)