1006 ANZJP Correspondence Australian & New Zealand Journal of Psychiatry, 46(10) Many drugs can cause a hypersensi- tivity myocarditis. Requiring a baseline echocardiogram would mean pre- scribing any one of them would be a significant burden on health service budgets. Until there is evidence that baseline echocardiogram can identify those at particular risk of myocarditis, or improve early detection of this condition, the use of this resource seems unjustified. Clinical review is the lodestone of identification of myocarditis. Clozapine is often commenced during inpatient care, which offers more opportunity for close clinical monitoring than when mesalazine or phenytoin (also linked with hypersensitivity myocarditis) are initiated in the community. We therefore suggest that expensive baseline echocardiograms be foregone in place of documentation of a patient’s previous medical (including cardiac) his- tory and a thorough cardiac examina- tion before prescribing clozapine. See Original Article by Ronaldson et al., 2011, 45(6): 459–465 References Kilian J, Kerr K, Lawrence C, et al. (1999) Myocarditis and cardiomyopathy associated with clozapine. Lancet 354: 1841–1845. Magnani JW and Dec JW (2006) Myocarditis: Current trends in diagnosis and treatment. Circulation 113: 876–890. McCormack M, Alfirevic A, Bourgeois S, et al. (2011) HLA-A*3101 and carbamazepine- induced hypersensitivity reactions in Europeans. New England Journal of Medicine 364: 1134–1143. Ronaldson KJ, Fitzgerald PB, Taylor AJ, et al. (2011a) A new monitoring protocol for clozapine-induced myocarditis based on an analysis of 75 cases and 94 controls. Australian and New Zealand Journal of Psychiatry 45: 459–465. Ronaldson KJ, Fitzgerald PB, Taylor AJ, et al. (2011b) Clinical course and analysis of ten fatal cases of clozapine-induced myocarditis and comparison with 66 sur- viving cases. Schizophrenia Research 128: 161–165. Clozapine-induced myocarditis and baseline echocardiography Kathlyn J Ronaldson 1 , Paul B Fitzgerald 2 , Andrew J Taylor 3 , Duncan J Topliss 4 and John J McNeil 1 1 Department of Epidemiology and Preventive Medicine, Monash University, The Alfred Centre, Melbourne, Australia 2 Monash Alfred Psychiatric Research Centre, Alfred Hospital and Monash University, Melbourne, Australia 3 The Heart Centre, Alfred Hospital, Melbourne, Australia 4 Department of Endocrinology & Diabetes, Alfred Hospital, Melbourne, Australia Corresponding author: Kathlyn J Ronaldson, Department of Epidemiology and Preventive Medicine, Monash University, The Alfred Centre, 99 Commercial Road Melbourne, VIC 3004, Australia. Email: kathlyn.ronaldson@monash.edu DOI: 10.1177/0004867412449299 We are grateful for the opportunity, presented by the commentary of Ellis and Cameron (2012), to explain in detail our reasons for proposing baseline echocardiography before commencing clozapine as part of the process of monitoring for clozapine- induced myocarditis (Ronaldson et al., 2011a). As these authors rightly point out, there is no evidence that pre- existing cardiac disease is a risk factor for myocarditis associated with clo- zapine; in fact, to the contrary, there is some indication from fatal cases that coronary artery disease does not change the risk (Ronaldson et al., 2011b). The reasons we have pro- posed baseline echocardiography do not include risk detection or early diagnosis, which are the criteria Ellis and Cameron (2012) consider would justify baseline investigation. The detection of left ventricular dysfunction involves considerable sub- tlety, except when the impairment is gross. While recent expert cardiol- ogy opinion recommends a cut-off of 55% for the diagnosis of a normal left ventricular ejection fraction, there is significant overlap of this fig- ure between normal and disease states (Lang et al., 2005); therefore, an assessment of left ventricular sys- tolic function without a baseline echocardiography for serial compari- son is problematic. Thus, baseline echocardiography will improve the reliability of diagnosis of myocarditis and reduce unnecessary discontinu- ation of clozapine, including discon- tinuation for pre-existing conditions. Unfortunately, as our investigations have shown, myocarditis can develop without troponin being raised above the upper limit of normal, so the diag- nosis cannot always be verified by checking troponin (Ronaldson et al., 2011a). In addition, apart from suicide, occult cardiac disease is the highest cause of sudden or unexpected death in schizophrenia, with an incidence that is significantly higher than that in the general community (Abdelmawla and Mitchell, 2006). The most com- mon causes of sudden cardiac death are coronary artery disease and car- diomyopathy (Kirchhof et al., 2006), both of which would be expected to be identified by baseline echocardiog- raphy, but not necessarily from rou- tine clinical evaluation. Hence, we believe a baseline echo- cardiography prior to commencing clozapine is clinically warranted, for these two reasons: so that myocardi- tis, when it is suspected, can be diag- nosed with a high degree of specificity, and to detect in the patient with schizophrenia any cardiac disease which would benefit from appropri- ate treatment. See Commentary by Ellis and Cameron, 2012, 46(10): 1005–1006