Drugs, Electrolytes and Tako-tsubo Cardiomyopathy: Triple Aetiology of Acquired Long Qt Syndrome and Torsades De Pointes

We conclude that coronary anatomy is independent of the human genome. Disease lesion sites are at least partly independent of the human genome. In contrast, age at first cardiac event, type of cardiac event and risk factor profile appear to be more closely related to genetic profile. We suggest that when one twin presents with IHD, the second should be subject to increased medical surveillance Comparative coronary anatomy in six twin pairs with coronary artery disease. drugs, eLectroLytes and tako-tsubo cardiomyoPathy: triPLe aetioLogy oF acquired Long qt syndrome and torsades de Pointes. Editor, Physical or emotional stress can have unforeseen consequences. We document a 67 year-old female admitted with syncope following emotional stress. She had a history of depression and had been " crying and crying all day ". In addition, she had a history of ileostomy following severe diverticular disease. Her daily medication included ondansetron 4mg b.d. for nausea and fluoxetine 60mg for depression. On admission, serum magnesium was low at 0.73mmol/l (0.75 – 1.25) and serum potassium was 3.9mmol/l (3.5 – 5.1). Troponin I was mildly elevated at 0.17u/l (0 – 0.04). B-type natriuretic peptide (BNP, Abbott) was grossly elevated at 2569pg/ml (normal < 100). Initial ECG (fig 1) showed new T wave inversion in ECG leads; II, III, aVf and V1 through to V6 with a prolonged corrected QT interval (QTc) of 524ms (upper limit of normal for females = 450ms). An ECG dated June 2007 was normal apart from a QTc of 509ms. She was initially treated as an anterior non-ST segment elevation myocardial infarction. Shortly after admission, she developed polymorphic ventricular tachycardia (torsades de pointes, figure 2). The risk of torsades de pointes increases substantially once QTc is > 500 ms. This was treated with a 200J DC shock, 4mmol of intravenous magnesium with oral beta-blocker, and potassium therapy. Further self-terminating runs of torsades de pointes occurred when her potassium levels dipped below 4mmol/l. On day two, she underwent cardiac catheterisation, which showed normal coronary arteries but marked impairment of systolic function in the apical half of the left ventricle with a characteristic " ballooning " appearance (figure 3). These findings, in association with physical or emotional strain, are diagnostic of tako-tsubo cardiomyopathy. Oral magnesium supplements and bisoprolol 5mg were added in to her medication. Ondansetron and fluoxetine both prolong the QT interval and were stopped. A cardio-defibrillator device was Fig 1. Coronary angiograms from …