Chloroquine (CQ) and hydroxychloroquine (HCQ) are anti‐rheumatic medications frequently used in the treatment of connective tissue disorders. We present the case of a 45‐year‐old woman with CQ‐induced cardiomyopathy leading to severe heart failure. Electrocardiographic abnormalities included bifascicular block, while structural disease consisted of severe biventricular and biatrial hypertrophy. Appropriate diagnosis via endomyocardial biopsy led to cessation of CQ and subsequent dramatic improvement in symptoms and structural heart disease. Cardiac toxicity is an under‐recognized adverse effect of CQ/HCQ leading to cardiomyopathy with concentric hypertrophy and conduction abnormalities, with the potential for significant morbidity and mortality. Predisposing factors for CQ/HCQ‐induced cardiomyopathy have been proposed. CQ/HCQ cardiomyopathy is a phenocopy of Fabry disease, and α‐galactosidase A polymorphism may account for some heterogeneity of disease presentation.

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This section is dedicated to case studies which illustrate the applications of mathematics to contemporary industrial problems. Submissions of ten typed pages or less are preferred, but this limitation may be waived for articles of exceptional interest.Submissions should be sent in duplicate to Jack Macki, Abstract. A planning method is presented, which we have used to analyse the implications of changes in key parameters for systems planning in considering the remote terminal access to a centralised system with a partial database as an interim path toward client-server systems. Calculations have provided a three-dimensional (3d) representation of the five parameters of cost per transaction, distributed/centralised ratio and speed of server, cycles per transaction, and degree of multiprogramming. The 3d surface has a cusp property which, if not appreciated visually, can lead to undesirable planning pathways of system sizing due to discontinuous effects in the catastrophe theory of such surfaces. A graphic visual presentation, rather than text or tabular presentations, utilises the great bandwidth that the visual system provides to the brain to assist in decision making and is used herein to increase awareness of planning features that are often not readily appreciated. The planning progression using a 3d visual application of the situation can also logically lead to the stage for the decision between a distributed database system or a further extension of a centralised system, depending on transaction loads and the nature of database accesses required.