ABC | Volume 115, Nº1, July 2020

Review Article Costa et al. Cardiovascular Imaging and Interventional Procedures Arq Bras Cardiol. 2020; 115(1):111-126 the management of the case. 5 All elective echocardiographies, such as, TTE, TEE, stress echocardiography (SE) and fetal echocardiography (FE), should be postponed until such time as the pandemic has waned. The need for urgent echocardiography on an outpatient setting should be assessed on a case-by-case basis; however, an urgent exam is the one whose result can prevent an adverse event or hospitalization within 2 to 4 weeks. 17 In light of this, urgent echocardiography is recommended in the following situations: suspicion of new symptomatic heart disease [New York Heart Association (NYHA) functional class III/IV]; worsening of preexisting heart failure with severe symptoms (syncope, chest pain, NYHA functional class III/IV); cancer therapy with cardiotoxic drugs and suspected heart failure or previous reduction in ejection fraction; suspected severe symptomatic aortic stenosis; high pretest probability of infective endocarditis in a patient with valvular prosthesis and acute symptoms. 17 Routine echocardiography for the follow-up of patients without severe symptoms or noneligible individuals for urgent clinical, surgical or invasive therapy should be deferred or canceled. For inpatients, the indications for urgent echocardiography are usually the same as before the pandemic. 3.3. Indications for Echocardiography in Patients with Suspected or Confirmed COVID-19 Echocardiography remains an essential imaging technique during the coronavirus pandemic. The considerations “in whom”, “how” and “where” to use it are fundamental to reduce the risks of contamination, and, at the same time, to ensure high-quality medical care. Some authors advocate the use of TTE in all patients with complicated COVID-19 (electrocardiographic changes, increased troponin levels, moderate to severe symptoms requiring hospitalization), 12,18 specially in the presence of previous cardiovascular disease. Although there is no formal indication supported by solid scientific evidence, it is worth noting the importance of assessing cardiac function because of the potential simultaneous occurrence of previous and acute cardiovascular disease in patients with severe COVID-19. Zhou et al. 9 have reported heart failure in 23% of patients with COVID-19 and associated it with higher mortality (51.9% versus 11.7%). 9 It is not clear whether that heart failure rate was due to aggravation of a previous ventricular dysfunction, new heart disease or both. Patients with previous ventricular dysfunction can develop severe heart failure decompensation in severe COVID-19, accompanied by hypotension and/ or cardiogenic shock. Several possibilities have been suggested for acute myocardial injury, such as direct viral effect (myocarditis), hypoxic injury, toxic effect via “cytokine storm”, vasospasm, thrombosis, myocardial stunning due to stress cardiomyopathy, and hemodynamic instability. 19-21 The possibility that SARS-CoV-2 causes myocarditis has been widely discussed. In a series of 150 patients with COVID-19, the retrospective analysis of 68 deaths has attributed 53% of them to respiratory failure, 7% to myocarditis with circulatory shock, 33% to a combination of both, and 5% to unknown causes. 15 The authors have used clinical data to diagnose fulminant myocarditis, with no biopsy confirmation. Similarly, fulminant myocarditis has been reported in patients with and without fever, who had chest pain, ST-segment elevation with no coronary obstruction, and severe ventricular dysfunction, and who responded to salvage therapy with corticoid and immunoglobulins. 22,23 Although in these two studies CMRI had shown findings compatible with myocarditis, there was no histological confirmation. 22,23 The differential diagnosis with myocarditis and stress cardiomyopathy necessarily includes acute coronary syndromes, which have also been reported in patients with COVID-19. 24,25 The intense inflammatory response and hemodynamic changes associated with severe COVID-19 might increase the risk of rupture of atherosclerotic plaques and/or thromboembolic phenomena in susceptible patients. 14 Even for those with neither fever nor cough, who have typical cardiac manifestations, COVID-19 should be considered in the differential diagnosis during the pandemic, and echocardiography can aid clinical judgment. Cardiac arrhythmias are common in inpatients with COVID-19, being described in 16.7% of the cases in a Chinese cohort with 138 patients. 7 Echocardiography can be useful, especially for malignant ventricular arrhythmias, by diagnosing left ventricular dysfunction or preexisting structural heart disease. Regarding severe pneumopathy and ARDS, association with pulmonary hypertension and right ventricular dysfunction should be assessed. Pericardial infusion has been reported as an exam finding associated with myocarditis (myopericarditis), usually without significant hemodynamic repercussion. 22,23 In the following clinical scenarios, the indication for echocardiography in patients with COVID-19 seems defensible: 12,17,18,26 • Suspected heart failure • Enlarged heart on chest X-ray • Clinically significant arrhythmias • Chest pain with electrocardiographic changes and/or troponin elevation • Hemodynamic instability and/or shock • Suspected pulmonary hypertension and/or right ventricular dysfunction For patients with severe COVID-19 admitted to the intensive care unit, bedside, and preferably point-of-care, echocardiography is recommended on admission and during the course of disease. 5,12 3.4. Special Protocols During the Pandemic 3.4.1.Transthoracic echocardiography: the exam should have its length reduced to a minimum and be targeted at the suspected diagnosis. Because the risk of contamination increases as the duration of the exam lengthens, the use of focused echocardiography, rather than complete TTE, has been recommended. 5,17,26 Nevertheless, unnecessary repetition of exams should be avoided, and, according to the complexity of the case, complete TTE might be required to meet clinical demand. Images should be stored aiming at performing the off- line measurements, and electrocardiographic monitoring can be dismissed. Ideally one exclusive echocardiography device 113