ABC | Volume 113, Nº1, July 2019

Statement Position Statement on Indications of Echocardiography in Adults – 2019 Arq Bras Cardiol. 2019; 113(1):135-181 commonly used in practice, which is useful for the detection of subclinical myocardial dysfunction, even when LVEF is preserved; for example: evaluation of cardiotoxicity after the use of chemotherapy for antineoplastic treatment, rejection after heart transplantation, severe aortic stenosis, hypertrophic cardiomyopathy and myocardium infiltrative diseases. 15-19 2.2. Left Ventricular Diastolic Function The evaluation of LV diastolic function is an integral part of routine echocardiography analysis, especially in patients with dyspnea or suspected heart insufficiency. 20,21 Furthermore, in several cardiopathies, the diastolic dysfunction precedes the systolic one. Diastolic dysfunction is usually the result of altered relaxation, with or without reduction of restorative forces (early diastolic suction), and increased LV stiffness, leading to elevated LV filling pressures. 20 When pulmonary capillary pressure exceeds 12 mmHg, or final diastolic LV pressure exceeds 16 mmHg, filling pressures are considered high. 21 Elevation of filling pressures occurs as a compensatory response to maintain adequate cardiac output, and its estimation is important not only for the diagnosis of cardiac insufficiency but also for the definition of its severity and response to treatment. 21 It is recommended that the non-invasive analysis of diastolic function be performed by the integrated approach of several techniques, the most important ones being: Pulsatile Doppler of the mitral flow, tissue Doppler of the mitral valve annulus, left atrial volume (LA) indexed by body surface and tricuspid regurgitation velocity. 20 Pulmonary venous flow and Valsalva maneuver can be used as additional parameters in specific cases, which are useful in differentiating the degrees of diastolic dysfunction. 20 While pulsatile and tissue Doppler velocities reflect the instantaneous filling pressures of the LV, the measurement of the LA volume reflects the cumulative effect of filling pressures over time and, therefore, this index is the chronic expression of diastolic dysfunction. 22 However, it is important that other causes of LA enlargement are discarded and that this data is taken into consideration along with the patient’s clinical condition, chamber size and Doppler indices for the evaluation of diastolic function. In individuals with preserved systolic function and without structural heart disease, diastolic dysfunction is considered if there is a change of more than 50% of the following 4 parameters: relationship between the early diastolic velocity of mitral inflow (E) and the early diastolic velocity of the mitral annulus (e’) E/e’ mean > 14; septal e´ velocity’ < 7 cm/s or lateral < 10 cm/s; tricuspid regurgitation velocity > 2.8 cm/s and LA indexed volume > 34 mL/m. 20,21 For the group of patients with systolic dysfunction and those with preserved systolic function concomitant with the presence of cardiac disease (clinical or echocardiographic manifestation), the integrated use of the information allows us, in most cases, to estimate the ventricular filling pressures and the graduation of diastolic dysfunction. 20 Three patterns of diastolic dysfunction are defined, in ascending order of severity: grade I (abnormal ventricular relaxation without increase of filling pressures); grade II (elevation of filling pressures coexisting with altered relaxation, usually presenting “pseudonormal pattern” of the mitral flow); and grade III (very high filling pressures, accompanied by a restrictive pattern of the mitral flow). To define the presence of increased filling pressures in this group with heart disease, we must first analyze the mitral flow, before other parameters. The relationship between E and the atrial diastolic velocity of the mitral inflow (A) E/A ≤ 0.8 (with E-wave ≤ 50 cm/s) is compatible with normal filling pressures and isolated abnormal relaxation, while the relation E/A ≥ 2 is consistent with elevated filling pressures. However, for cases with an E/A > 0.8 and < 2, an abnormalityof at least 2 of the following 3 parameters is required: E/e’; tricuspid refurgitation velocity; and LA indexed volume. In some cases, the definition criteria for diastolic dysfunction are not completely fulfilled, and thus the degree of diastolic dysfunction can be reported as indeterminate. 20 This algorithm for the evaluation of diastolic dysfunction from the echocardiography has recently been validated in a multicenter study which assessed patients with and without left ventricular systolic dysfunction. 23 Non-invasive evaluation of filling pressures by echocardiography correlated with the diastolic pressures measured by catheterization, showing greater accuracy than isolated clinical parameters. 23 It should be noted that the parameters for evaluation of diastolic function may present important limitations in specific situations, such as hypertrophic cardiomyopathy, mitral annular calcification, severe mitral regurgitation, cardiac transplantation and cardiac arrhythmias. 20 Some patients, even with grade I diastolic dysfunction defined at rest, become symptomatic only during exercise and therefore it may be useful to analyze filling pressures during physical stress (diastolic stress echocardiography). 20,24 Patients with diastolic dysfunction are unable to increase ventricular relaxation with exercise, when compared to normal subjects, with increased filling pressures, which can be identified by increased E/e’ ratio and tricuspid regurgitation velocity. 24 In normal patients, velocities of E and e’ increase proportionally and the index remains constant. Finally, the evaluation of diastolic function using techniques derived from strain and strain rate is promising, but requires further studies to establish its additional clinical value. 20 2.3. Cardiomyopathies Cardiomyopathies are a heterogeneous group of myocardial diseases associated with mechanical and/or electrical dysfunction, which usually exhibit inappropriate ventricular hypertrophy or dilatation, due to a variety of causes, often genetic. 25 Cardiomyopathies are confined to the heart or are part of generalized systemic disorders. The classification is based on functional or structural changes in the following subtypes: dilated, hypertrophic, restrictive, and arrhythmogenic cardiomyopathy (or dysplasia) of the right ventricle (RV), more recently referred to as arrhythmogenic cardiomyopathy. 26 Subsequently, as the knowledge on the genetics foundations of cardiomyopathies developed, other classifications have been proposed, subdivided into genetic, acquired and mixed. 26 More recently, channelopathies and related disorders, such as long and short QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia, have been included in the group of cardiomyopathies, since they are cardiomyocyte diseases characterized by arrhythmogenic electrophysiological dysfunction. 25,26 140