Rol del electrocardiograma en el diagnóstico de hipertrofia y los diferentes modelos de geometría ventricular izquierda / Role of the electrocardiogram in the diagnosis of hypertrophy and the different models of left ventricular geometry

El diagnóstico certero de la hipertrofia ventricular izquierda (HVI) se establece mediante un ecocardiograma transtorácico (ETT). El electrocardiograma (ECG), de menor costo, no es la técnica ideal debido a su baja sensibilidad para HVI. Sin embargo, posee una especificidad elevada para esta enfermedad. Los objetivos principales del presente estudio fueron: a) evaluar sensibilidad (S), especificidad (E), valor predictivo positivo (VPP) y valor predictivo negativo (VPN) de distintos criterios electrocardiográficos usados habitualmente para el diagnóstico de HVI; b) conocer las posibles razones de la baja sensibilidad que tiene el ECG; c) conocer si los valores patológicos más bajos del índice de masa ventricular izquierda (IMVI) son detectables sólo por ETT, y no adquieren manifestación electrocardiográfica sino en estadíos muy avanzados, cuando el IMVI es mayor. Por esta razón, los pacientes poseedores de un ECG con criterio diagnóstico positivo se asociarían a valores de IMVI más altos dentro del total de ETT con diagnóstico de HVI.Se compararon diversos índices electrocardiográficos (Sokolow, Lewis, Cornell, Jinish, voltaje en aVL de Sokolow, Ungerleider y Romhilt- Estes) con las ecocardiografías de esos mismos pacientes analizadas según los criterios de la Sociedad Americana de Ecocardiografía. Se halló que: 1. El ECG tiene una baja S, moderado VPN, elevada E y elevado VPP, sin haber grandes diferencias entre los índices electrocardiográficos. 2. De los parámetros ecocardiográficos, sólo el IMVI se encuentra alterado en los ECG positivos. 3. El grupo de pacientes con diagnóstico electrocardiográfico de HVI, no se asocia a un IMVI mayor que el de la totalidad de pacientes con diagnóstico ecocardiográfico.

The accurate diagnosis of left ventricular hypertrophy (LVH) is established by means of transthoracic echocardiography (TTE). The electrocardiogram (ECG), of lower cost, is not the ideal technique due to its poor sensitivity for LVH. However, it shows a high specificity for this pathology.The main objectives of this study were as follows: a) to evaluate the sensitivity(S), the specificity (SP), the positive-predictive value (PPV) and the negative-predictive value (NPV) of different electrocardiographic criteria often used for LVH diagnosis; b) to determine possible reasons for the low sensitivity of ECG; c) to determine if low, but pathological, values of the left ventricular mass index (LVMI) are detectable only by TTE, as they do not acquire electrocardiographic manifestation but in advanced phases, when the LVMI is higher. Thus, patients with a positive diagnostic according to ECG would be associated to higher values of LVMI within the total of TTE with diagnosis of LVH. Several electrocardiographic criteria for LVH (Sokolow, Lewis, Cornell, Jinish,Sokolow’s aVL voltage, Ungerleider and Romhilt-Estes) were compared with the TTE of the same patients, evaluated according to the criteria of the American Society of Echocardiography. We found that: 1. The ECG has a low S, moderate NPV, high E and high PPV, without big differences among indexes. 2. Only the LVMI is abnormally elevated among patients with positive electrocardiographic criteria. 3. The patients group with electrocardiographic diagnosis of LVH, is not associatedwith a higher LVMI, when compared with all the patients with echocardiographic diagnosis.

Hipertensión pulmonar / Pulmonary hypertension

Pulmonary Hypertension is a term to describe the increase in the pulmonary arteries pressure. The primary pulmonary hypertension is an illness characterized by sustained elevation in the pulmonary arteries pressures; is a rare disease associated with a poor long-term prognosis. The development of new diagnostic tests and an appropriate classification of the pulmonary hypertension have improved the identification and treatment of the secondary causes resulting in an increased survival. Recent findings suggest a multifactorial etiology, including genetics mutations and environmental factors. The novel vasodilators drugs like prostacyclin have changed the natural history of pulmonary hypertension; consequently, the surgical strategies are currently indicated only in the case of failure of medical treatment. Despite of these advances, new investigations will be necessary to find the cure of the pulmonary hypertension.