[ECG repolarization disorder (QT lengthening) in organophosphate poisoning]

The authors investigated in human and in experimental organophosphate intoxication the features of the toxic ECG repolarisation disturbance, the QT lengthening and its connection with cholinesterase depression. It was concluded that this pathological electrophysiological change in human intoxication does not show close correlation with the decrease of enzyme activity and cannot be influenced by atropine. The ECG alteration can be reproduced in animal experiments, it precedes the toxicologically relevant cholinesterase depression, it is pesticide dose dependent, but it cannot be induced by cholinergic or adrenergic drugs. On the basis of all this it is supposed that in organophosphate intoxication the QT lengthening reflects a direct myocardial pesticide effect and, is independent of cholinergic mediation.