Inferior Subtle ST Elevation. Would You Activate Cardiac Catheterization Laboratory?

BACKGROUND: According to guidelines, patients with inferior myocardial infarction only qualify for emergent reperfusion if they have at least 1 mm of ST elevation in two contiguous inferior leads. Although this has remained the standard for years, acute coronary occlusion may occur in patients with nondiagnostic ST elevation. Accordingly, a paradigm change is instigated, shifting the focus to physiopathology (occlusion myocardial infarction) rather than ST criteria. CASE REPORT: A middle-aged man presented to our emergency department with chest pain and subtle nondiagnostic electrocardiography (ECG) changes in inferior leads. A careful examination of aVL to detect ST depression in this lead was the key to successfully diagnosing occlusion myocardial infarction, allowing early revascularization of an occluded right coronary artery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Accurate diagnosis of coronary occlusion by means of ECG can be challenging in certain situations, as acute myocardial ischemia may occur in patients with nondiagnostic ST elevation, especially in the inferior leads. A thorough examination of aVL searching for ST depression is essential in these situations.

Elevación persistente de troponina I / Persistent elevation of troponin I

Resumen La troponina cardiaca es el marcador bioquímico más sensible y específico de daño/necrosis miocárdica, de ahí que desempeñe un papel crucial en el diagnóstico del síndrome coronario agudo. Sin embargo, en ocasiones, como en el caso clínico que se describirá, la elevación anormal de troponina no siempre obedece a un síndrome coronario agudo trombótico, sino a causa cardiaca sin enfermedad coronaria significativa, causa extracardiaca o alteración analítica (verdaderos falsos positivos). El interés de este caso radica en que siempre debería tenerse en mente la posibilidad de que se produzca un falso positivo de troponina por causa analítica, en especial en situaciones clínicas sin una razón obvia de daño miocárdico y cuando no sea evidente la confirmación de daño miocárdico mediante pruebas complementarias.

Abstract Cardiac troponin is the most sensitive and specific biochemical marker for myocardial damage / necrosis, and thus has a crucial role in the diagnosis of acute coronary syndrome. However, occasionally, as in the clinical case that will be described, the abnormal elevation of troponin does not always obey that of an acute coronary syndrome, but also to a cardiac cause with no significant coronary disease, extra-cardiac cause, or analytical change (true false positives). The interest in this case lies in that it should always be borne in mind that a false positive troponin can be produced due to an analytical cause. This can be the case in clinical situations with no obvious reason for myocardial damage and when the confirmation of myocardial damage may not be evident using complementary tests.