ABC | Volume 110, Nº4, April 2018

Original Article Santos et al Applicability of LV S2DL in unstable UA Arq Bras Cardiol. 2018; 110(4):354-361 Methods This is a cross-sectional, descriptive, performed at the Emergency Room (ER) and Coronary Unit (CU) of Dante Pazzanese Institute of Cardiology (IDPC). Inclusion criteria were: hospitalized patients of both sexes, age greater than 18 years and clinical diagnosis of UA who were admitted to IDPC service during the study period and who accepted the participation in the study, having signed informed consent form. We emphasize that there was no calculation of sample size. A census was carried out of all patients who had inclusion criteria. Patient arrival to IDPC service was by convenience. Exclusion criterion was the change in diagnosis during hospitalization. These cases occurred in patients who entered the service with initial chest pain and after propaedeutic and complementary exams, diagnosis of UA was ruled out. In case of differential diagnosis and closing as final diagnosis: acute myocardial infarction (AMI) with supra or no supra-ST segment, aortic dissection, pulmonary embolism and aortic stenosis. We a n a l y z e d c l i n i c a l - e p i d em i o l o g i c a l a n d electrocardiographic characteristics, as well as tests collection for troponin I and creatinine. Risk stratification was done using GRACE risk score. 8.9 Electrocardiographic analysis was performed by two experienced cardiologists; in case of disagreement regarding the diagnosis, tracing would be analyzed by a specialized service in the electrocardiographic reports of the institution where the research was carried out. Transthoracic echocardiography was performed within 48 hours of patient precordial pain last episode in ER or CU. The equipment for conducting examination was GE® Vivid E9 (General Electric Medical System, Norway) with transducer "array in phase" with 3.5 megahertz emission frequency. Images obtained during the examination were acquired with harmonic, in a repetition of frames between 50 and 70 frames/second, in digital clips form ( three consecutive cycles average) and recorded in CDs for later analysis in workstation EchoPAC PC version 6.0.1® (GE VingmedUltrasound). According to American Society of Echocardiography and European Society of Echocardiography committee guidelines, which standardized the acquisition of tomographic sections obtained during echocardiographic examinations, with the patient in left lateral decubitus and electrocardiogram monitored, we acquired transthoracicly echocardiographic images by the Spectral Doppler (pulsatile and continuous) Doppler and flow mapping in color. 10 Measures acquired: • Two-dimensional: diastolic and systolic left ventricular (LV) diameter, left atrium anteroposterior diameter (LA), aortic root diameter, interventricular septum and posterior wall thickness. LV diastolic and systolic volume. Calculation of LV ejection fraction (EF) by the modified biplanar Simpson method. • Doppler and Color Flow Mapping: Mitral flow with spectral Doppler (pulsatile and continuous) for diastolic function analysis and mitral valvopathy quantification, when present. Aortic flowwith spectral Doppler (pulsatile and continuous), to determine aortic valve opening and closing (to mark the systolic event), and aortic valvopathy quantification, when present. Valve lesions diagnosis and quantification followed American Society of Echocardiography recommendations. 11 The technique to obtain longitudinal tension was done as follows: • Marking systolic event with aortic flow pulsating Doppler. • Determination of three points of endocardial border in each of the following images: apical 3 chambers (at anterosseptal wall base, at inferolateral wall base and at apex), apical 4 chambers (at septum base, at lateral wall base and at apex) and apical 2 chambers (at inferior wall base, at anterior wall base and at apex). • Through the Automatic Function Imaging® (AFI) tool, the deformation of each of the 17 myocardial segments was automatically calculated, providing posteriorly left ventricle global deformation (analyzed segments mean). The program provides SL2D curves and polar map with longitudinal strain values in each segment. The maximum absolute value of the two-dimensional strain curve was defined as the systolic peak. Adjacent myocardial segments with altered strain value were defined as ischemic territory, correlating them with coronary irrigation, according to polar map shown in Figure 1. According to the literature, 7,12,13 the situations mentioned below may lead to a change in myocardial deformity, or to a real deformity impairment, or by limitation of the software to identify acoustic marks during the cardiac cycle: • Concentric ventricular hypertrophy (LVH); • Aortic and/or mitral valvar diseases greater than moderate degree; • Pacemaker pace; • At least one of the following electrocardiographic changes: left bundle branch block (LBBB), atrial fibrillation (AF) rhythm and complex ventricular arrhythmia; • Secondary unstable angina (acute anemia, tachyarrhythmia and infection); • Prior AMI or prior myocardial (percutaneous or surgical) revascularization procedure and • Inadequate acoustic window. Based on the above, we hypothesized that the presence of one of these alterations may impair SL2D analysis in severe coronary disease identification in UA patients. These concepts has fundamental importance for the knowledge of SL2D real applicability in this population, when the examination purpose is to evaluate coronary disease responsible for the acute condition. Patients eligible for bidimensional echocardiogram with longitudinal strain were submitted to the method by two skilled and experienced professionals, who did not have access to information on patient coronary anatomy evaluated until the conclusion of the study. 355