Clozapine-induced cardiotoxicity: a clinical update

Clozapine is a valuable drug for patients with treatment-resistant schizophrenia. Myocarditis is the most publicised cardiac complication of clozapine treatment, but cardiomyopathy and pericarditis have also been reported. Myocarditis has heterogeneous and non-specific presenting features, making it difficult to identify patients with clozapine-related myocarditis clinically. A high index of suspicion is required. The gold standard for diagnosis of myocarditis is an endomyocardial biopsy, but this is not a practical initial approach. Transthoracic echocardiography is a valuable, reproducible and widely available tool to assist in diagnosis of clozapine-induced cardiotoxicity. The level of B-type natriuretic peptide, a hormone secreted in response to ventricular wall stress, may be useful for evaluating patients with clozapine-induced cardiac dysfunction and may in the future be useful for screening asymptomatic patients. The mainstay of treatment of clozapine-induced cardiotoxicity is cessation of clozapine and provision of supportive care.