Obstruction of ECT seizure by submaximal hyperventilation: a case report.

Extreme obstruction of ECT seizure induction occurred in an elderly female with a low cardiac ejection fraction after a 20 to 25 s interval between the last ventilation and the electrical stimulus. Stimuli of 378 and 504 mC induced no motoric or EEG activity after an initial stimulus of 227 mC produced just 1 s of motoric seizure activity. After prolonged hyperventilation and immediate stimulation a seizure resulted with 33 s of motoric activity. This case suggests that patients with a low cardiac output might be particularly sensitive to the quality of ventilation.