[The heart and lithium. Apropos of a case of lithium poisoning with intracavitary electrocardiographic exploration].

Among the secondary effects of the salts of Li+, which are widely used in psychiatric treatment, cardiac toxicity appears to be rare. The authors report the case history of a female of 24 years of age, with no previous cardiac history, who presented with Li+ intoxication and a supra-His atrio-ventricular block, followed by episodes of sinus arrest (or of sino-atrial block), accompanied by either a junctional rhythm or by periods of prolonged asystole. The results of the endocavitary electrocardiographic investigation are described. These cardiac effects are compared with the general findings reported in the literature; ECG modifications of the T wave are more common, but Li+ may cause other changes: sinus, atrial or ventricular arrhythmiás, disorders of AV conduction, and cardiomyopathies. The main modes of action which have been suggested are of interference with the other cations (K+, Na+, Ca++) in exchanges across membranes, and an effect on membrane adenyl-cyclase stimulated by catechol-amines.