Cardiovascular Changes following Electro-convulsive Therapy.

Electro-convulsive therapy was first used extensively in 1939, and with such success that three years later Kolb and Vogel (1942) in a survey ofthe United States reported its use in 42 per cent of mental hospitals and in the treatment of 2-3 per cent of all mental hospital patients; this latter group was comprised of the schizophrenias, the manic-depressive states, involutional melancholias, and the psychoneuroses. As convulsant treatment is now of established value in the affective neuroses and as electric shock has largely superseded insulin and metrazol as a convulsant, it seemed pertinent to attempt some assessment both clinically and electrocardiographically of its effect on the cardiovascular system. These observations consisted of a clinical history (which by the nature of the psychiatric condition was not always complete), a routine examination of the cardiovascular system and electrocardiograms (standard leads only) both before and after the convulsion. The second cardiogram was taken in the recovery phase directly after the clonic movements had ceased; in some instances there was slight delay due to uncontrollable spasmodic movements. The patients in this series were not specially selected; a quarter were observed during their initial treatments. The convulsant apparatus used was that of Strauss and MacPhail (1946), which by means of a rapidly discharging condenser yields the higher voltages at the start, thereby overcoming the initial resistance, and as only minimal energy is then necessary to induce the fit, the equally rapid damping minimizes subsequent neuronic bombardment. The time factor is therefore of less importance and the dosage is reckoned in Joules or total energy rather than in in volts: this varies according to weight and general fragility; the usual dosage in this series was 18 Joules diphasic. A monophasic discharge yields a quieter recovery but is less certain in inducing a convulsion. The electrodes, soaked in 20 per cent saline, are applied to the temples, anterior to and a little above the external auditory meati. The duration of the shock is, variable, lasting about 0 35 sec.; unconsciousness is instantaneous and is succeeded by a tonic phase, thence a clonic phase, which in turn is followed by exhaustion and relaxation or irritability, from which consciousness is recovered in from four to fifteen minutes-a consciousness clouded by disorientation and amnesia. Occasionally the shock may produce a " stun" only, the patient remaining conscious. Successive "-stuns " may induce cardiovascular collapse. The average duration of the tonic phase, as observed in 22 patients, was 16 seconds, of the clonic phase 25 seconds. The length of the tonic period bore no relationship to that of the clonic. Directly after the shock oxygen was administered by mask, and as the tonic phase is short, cyanosis was not observed.