Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc
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Ann Noninvasive Electrocardiol · Jul 2004
ReviewBrugada and long QT-3 syndromes: two phenotypes of the sodium channel disease.
Brugada and long QT-3 syndromes are two allelic diseases caused by different mutations in SCN5A gene inherited by an autosomal dominant pattern with variable penetrance. Both of these syndromes are ion channel diseases of the heart manifest on surface electrocardiogram by ST-segment elevation in the right precordial leads and prolonged QT(c) interval, respectively, with predilection for polymorphic ventricular tachycardia and sudden death, which may be the first manifestation of the disease. Brugada syndrome usually manifests during adulthood with male preponderance, whereas long QT3 syndrome usually manifests in teenage years, although it can also manifest in adulthood. ⋯ The only effective treatment available at this time for Brugada syndrome is implantable cardioverter defibrillator, although repeated episodes of polymorphic ventricular tachycardia can be treated with isoproterenol. In symptomatic patients of long QT-3 syndrome in whom the torsade de pointes is bradycardia-dependent or pause-dependent, a pacemaker could be used to avoid bradycardia and pauses and an implantable cardioverter defibrillator is indicated where arrhythmia is not controlled with pacemaker and beta-blockade. However, the combination of new devices with pacemaker and cardioverter-defibrillator capabilities appear promising in these patients warranting further study.
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Ann Noninvasive Electrocardiol · Jul 2004
ST-depression with negative T waves in leads V4-V5--a marker of severe coronary artery disease in non-ST elevation acute coronary syndrome: a prospective study of Angina at rest, with troponin, clinical, electrocardiographic, and angiographic correlation.
The significance of ST-segment depression in acute coronary syndrome has been the subject of debate for many decades. Studies indicate that different manifestations of ST/T changes may have significantly different prognostic implications. ⋯ In patients with non-ST-elevation acute coronary syndrome and elevated troponin levels two subgroups could be identified. Transient ST-segment depression and a negative T wave maximally in leads V4-5 during anginal pain predicts left main, left main equivalent, or severe three-vessel coronary artery disease with high sensitivity and specificity. In patients with ST-segment depression and a positive T wave, there is a high probability of one-vessel disease.