Reversal of pathologic cardiac parameters after transition from clozapine to olanzapine treatment: A case report

Hagit Cohen, Uri Loewenthal, Michael A. Matar, Moshe Kotler

    Research output: Contribution to journalArticlepeer-review

    18 Scopus citations


    Antipsychotic medications have been associated with significant cardiovascular adverse effects and instances of sudden cardiac death. Recently, we started to evaluate cardiac parameters in medicated patients with schizophrenia using power spectrum analysis of heart rate variability. We present a case of a patient with long-standing schizophrenia who was treated with clozapine. His electrocardiogram revealed minor abnormalities, including a prolonged QT interval. Power spectrum analysis of heart rate variability demonstrated marked abnormalities in autonomic nervous system activity. Two years later, his treatment was switched to olanzapine. We reevaluated his cardiac parameters. Power spectrum analysis studies revealed that heart rate had significantly improved and that power spectrum cardiovascular parameters had returned to normal. Serial electrocardiograms revealed a minimally and asymptomatically prolonged QT interval. This case demonstrates the importance of screening electrocardiograms, even in healthy young patients. It also emphasizes how minor changes in electrocardiogram can be overlooked on standard electrocardiograms. Power spectrum analysis of heart rate variability is useful in this instance because it magnifies the trace and detects even minor disturbances. Care should be taken in prescribing antipsychotic drugs to patients who are prone to cardiovascular side effects, and alternatives to antipsychotics with prominent anticholinergic profile, in particular, should be sought.

    Original languageEnglish
    Pages (from-to)106-108
    Number of pages3
    JournalClinical Neuropharmacology
    Issue number2
    StatePublished - 24 Apr 2001


    • Antipsychotic medications
    • Heart rate variability
    • Power spectrum analysis
    • Schizophrenia
    • Sudden death

    ASJC Scopus subject areas

    • Pharmacology
    • Clinical Neurology
    • Pharmacology (medical)


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