Browsing by Author "Okreglicki, Andrzej"

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    Open Access
    Amiodarone-induced thyroid dysfunction
    (2005) Ross, Ian Louis; Marshall, David; Okreglicki, Andrzej; Isaacs, Sedick; Levitt, Naomi Sharlene
    Background. Little is known about the frequency of thyroid dysfunction (TD) associated with amiodarone therapy in southern Africa. Objectives. To determine the incidence of TD in a cohort of patients initiated on amiodarone therapy at a cardiac clinic in Cape Town, South Africa, believed to be an iodine-replete area. Patients. Pharmacy records were used to obtain the names of patients who received amiodarone between November 1999 and December 2002. Results. The sample size was 194, but data analysis was limited to the 163 patients for whom there were complete data. The mean age ± standard deviation (SD) was 59.0 ± 15.0 years (range 22 - 89 years). There were 67 female and 96 male patients. The indications for amiodarone therapy were supraventricular tachycardias (N = 102, 62.6%), ventricular tachycardia (N = 55, 33.7%), and prophylaxis against tachycardias (N = 3, 1.8%). The indication was uncertain in 3 patients (1.8%). The median duration of amiodarone treatment was 679.0 days (quartile deviation (QD) 1 172 days, range 3 - 6 425 days) in the whole cohort. The median duration of amiodarone therapy until new TD was 943 days (QD 1 185 days), significantly longer than in patients who remained euthyroid (547 days, QD 1 135 days) (P = 0.05). There were 45 new TD cases (27.6%): 11 patients (6.7%) were thyrotoxic, 1(0.6%) transient thyrotoxicosis, 1 (0.6%) subclinical hyperthyroidism, 13 (8.0%) had subclinical hypothyroidism, 12 (7.4%) hypothyroidism and 7 (4.3%) had minor changes in thyroid function. Conclusions. We found a high incidence of new-onset TD, similar to the highest rates reported internationally. Local factors responsible for this need to be investigated.
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    Open Access
    QT-prolonging drugs: Should they ever be used?
    (2005) Okreglicki, Andrzej
    If the current stringent conditions of bodies that register and control medicines had been in force for decades, many commonly used drugs (from antibiotics and antihistamines to antipsychotics and antiarrhythmics) would never have reached the consumer market. Nowadays, pre-release findings of QT prolongation are likely to scupper early-phase trials and result in the abandonment of experimental drugs. Post-marketing surveillance has identified a number of commonly used drugs either as causing QT prolongation or associated with increased sudden unexpected deaths.1 Thioridazine (see p. 46 of this issue) is such a drug.
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    Technology in cardiology
    (Health and Medical Publishing Group, 2003) Okreglicki, Andrzej
    Clinical technology and cardiology have a synergistic relationship with regard to investigation and intervention. Echocardiography complements clinical cardiology, but does not replace competent history taking and clinical examination. Cardiac catheterisation and angiography still remain the ‘gold standard’ for most complex cardiac conditions. Digital radiology systems allow image manipulation, measurement, instant replay and easy storage with less radiation. Magnetic resonance imaging is the investigation of choice for aortic dissection and certain cardiomyopathies. Conventional intra cardiac contact arrhythmia mapping is adequate for the majority of arrhythmias that can be ablated. 3D mapping systems are useful in abnormal hearts or after surgery. Most percutaneous cardiac intervention can be done using PTCA balloons and stents. Complex lesions occasionally may require other expensive techniques that are generally not needed; such as atherectomy and intravascular ultrasound. Arrhythmia devices (pacemakers and ICDs) need careful follow-up with monitoring and interrogation, as adjustments after implantation may be necessary. Great ca re must be taken with computer-generated interpretation of investigations (e.g. ECG), as reliance on this could potentially be dangerous. Cardiac technology and information management have important associated ethical issues.