Nilsson BM, et al. - Given that tachycardia is a known clozapine adverse effect, researchers assessed if clozapine-associated tachycardia is persistent. In clozapine-treated patients, researchers measured HR with ambulatory electrocardiography (ECG) over 24 h that has never been studied before. The findings indicated a very high mean 24-hour HR in these patients, indicating a persistent tachycardia. Tachycardia should not abstain clinician from prescribing clozapine. However, a need of guidelines for detection and treatment of clozapine-associated tachycardia was realized.