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.