[Potentially lethal cardiac side effects caused by psychiatric drugs].

The objective of this article is to analyze some of the potentially lethal cardiac side effects of psychiatric drugs and to contribute with the necessary instruments to diagnose and treat them properly. Prolongation of the QT interval caused by most of antipsychotics is discussed, focusing on those drugs with greater risk: pimozide, thioridazine, ziprasidone and sertindole. The QT interval prolongation is a risk marker of arrhythmias like the torsade de pointes, a polymorphic arrhythmia that produces dizziness, syncope, ventricular fibrillation and sudden death. Arrhythmias caused by lithium are also considered. Even though they are unusual, they constitute the most common cardiac effect of treatment with this drug. Miocarditis and cardiomyopathy, although infrequent cardiac muscle diseases, are catastrophic but potentially reversible complications, mainly associated with clozapine. Last but not least, the diagnosis and clinical management of these adverse effects is reviewed.