New Universal Definition of Myocardial Infarction

Recently, a joint ESC/ACCF/AHA/WHF Task Force published an expert consensus document on the universal definition of myocardial infarction [1]. The following points are extracts from this document that summarize its main features. The main reason for agreeing on a new definition of myocardial infarction derives from the development and the wide availability of very sensitive and specific serological biomarkers that are able to detect even minimal myocardial necrosis. Acute myocardial infarction is diagnosed when there is evidence of myocardial cell necrosis in the clinical setting of myocardial ischemia. In contrast to the historical World Health Organization (WHO) definition where symptoms, ECG and enzymes had equal weight for the diagnosis (the presence of any two would suffice), today biomarkers take precedence with imaging having also a diagnostic role. Consequently, acute myocardial infarction is diagnosed if a rise and fall of cardiac biomarkers (preferably troponin) is detected together with at least one of the following: a) symptoms of ischemia, b) new ST-T changes or new left bundle branch block (LBBB), c) development of pathological Q waves and d) imaging evidence of new loss of viable myocardium or new regional wall motion abnormality.Prior myocardial infarction requires for its diagnosis any of the following criteria: a) new Q waves, b) imaging of a regional loss of viable myocardium that is thinned and fails to contract and c) pathological findings of a healed or healing myocardium

Reuse of Electrode Catheters and Pacemakers

Reuse of electrophysiology catheters and pacemaker devices has been practiced safely in several countries with significant cost-savings. Data from the literature evaluating clinical end-points, device-related complications, such as infections, and mechanical performance, suggest that this is a safe practice with no increased risk of complications or mortality. However, there remain practical, legal and ethical concerns which need to be addressed before a more widespread use of such practice is adopted. Also, protocols for validation of cleaning and sterilization, and estimations of the potential risks of infective agent transmission need to be more rigorous

Stable Coronary Artery Disease: When is Percutaneous Coronary Intervention Indicated?

In patients with chronic coronary artery disease (CAD) and good left ventricular function, percutaneous coronary intervention (PCI) does not confer any clear benefit in terms of hard long-term clinical outcomes, such as mortality, myocardial infarction or the need for subsequent revascularization, as compared with medical conservative treatment. Indeed, a meta-analysis of early data from 6 randomised controlled trials has showed convincingly that PCI improves anginal symptoms compared to conservative management, but there has been limited evidence on the effect of PCI on hard clinical outcomes. At the same time, the early fear of increased need for revascularization after PCI is probably not warranted. By comparing the benefits against cost considerations, it seems hat many percutaneous interventions that are currently performed in patients with non-acute CAD are probably not justified

Iron Overload and Myocardial Restriction

Heart failure still remains the main cause of death in β-thalassemia, despite the progress, which was made by intensification of iron chelation therapy. Iron myocardial deposition, due to regular blood transfusions, can cause congestive heart failure as a result of left- or right-sided heart failure combined with left ventricular myocardial restriction. Regular and intense chelation therapy has improved quality of life and survival by decreasing secondary hemochromatosis. However, heart failure has not been prevented despite the intensification of iron chelation therapy.             Acute myocarditis in β-thalassemia major has been reported to contribute to heart failure in addition to iron overloading. However, apart from myocarditis which may lead to immune mediated chronic left ventricular dysfunction and failure, other factors acting through immunologic or genetically defined mechanisms might also affect the development of left sided heart failure. Multiple transfusions represent a repetitive antigenic stimulus together with iron chelation therapy itself. In this brief overview, the pathogenetic mechanisms of myocardial involvement and heart failure in β-thalassemia major are discussed

Sustained Ventricular Tachycardia During Dobutamine Stress Echocardiography

Dobutamine stress echocardiography (DSE) has been frequently performed safely and renders important diagnostic information of underlying myocardial ischemia in patients with coronary artery disease. During DSE, death or other major events, such as myocardial infarction and sustained ventricular tachycardia (VT), have been extremely rare. We herein present three patients who developed three different types of sustained VT during DSE. These clinical observations indicate that various mechanisms may be involved in the development of this malignant arrhythmia during DES