Revisiting the Question
| Autor: | James J. Bailey, Michael M. Laks, David B. Geselowitz, Robert Arzbaecher, Alan S. Berson |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
medicine.medical_specialty
End point medicine.diagnostic_test business.industry Safety standards medicine.disease Ventricular tachycardia Surgery Physiology (medical) Ventricular fibrillation Ecg waveforms medicine Current (fluid) National standard Cardiology and Cardiovascular Medicine Intensive care medicine business Electrocardiography |
| Zdroj: | Circulation. 102:823-825 |
| ISSN: | 1524-4539 0009-7322 |
| DOI: | 10.1161/01.cir.102.8.823 |
| Popis: | This editorial is a follow-up to a 1994 editorial1 by the same authors with the same title. The 1994 editorial emphasized that revised national standards, which relaxed the maximum allowable current that may be delivered to patients by electromedical equipment, presented unnecessary hazards to patients with indwelling catheters, and it described the need to obtain more scientifically based data to resolve the issues. Recently published data obtained from patients undergoing testing of implanted defibrillators provide the first direct and dramatic evidence that current levels as low as 32 μA can cause hemodynamic collapse simulating ventricular tachycardia before ventricular fibrillation (VF) occurs.2 These currents cannot be felt, and their presence cannot be identified on ECG waveforms. Consequently, both the standards of the United States and the recommendations of the American Heart Association (AHA) now need to be reconsidered.3 4 We believe that the maximum allowable level of risk current must be changed back to the 1972 AHA recommendations of 10 μA, under single-fault conditions, regardless of the source or pathway of the current. The national standard of the United States, which now allows up to 50 μA in patient-connected leads and 300 μA of leakage current under single-fault conditions must be similarly changed.5 Current through the myocardium exceeding 10 μA places subjects at unnecessary risk. Furthermore, ventricular tachycardia with hypotension must be added as a new diagnostic and testing end point for electrical safety. The following history of the changing standards and various ways in which alternating current can get to the heart to produce cardiovascular collapse and/or VF is presented to emphasize that the lack of human data has been a barrier in developing a valid recommendation for electrical safety standards. The AHA interest in allowable risk currents dates from 1967, when the Committee on Electrocardiography … |
| Databáze: | OpenAIRE |
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