Epicardial Echocardiography—A Plausible Alternative Cardiac Imaging Technique in COVID-19 Pandemic

Abstract

Coronavirus disease 2019 (COVID-19), because of its high infectivity rate, created havoc across the globe.1Culp W.C. Coronavirus disease 2019.A A Pract. 2020; 14: e01218PubMed Google Scholar Healthcare workers are the most affected community, having high mortality across the world. Severe acute respiratory syndrome coronavirus 2 enters cells through angiotensin- converting enzyme-2 receptors, which are expressed mostly in lung and intestines.2Gao Q.Y. Chen Y.X. Fang J.Y. 2019 novel coronavirus infection and gastrointestinal tract.J Dig Dis. 2020; 21: 125-126Crossref PubMed Scopus (272) Google Scholar So, the virus load is increased in aerodigestive tract secretions. Any procedure involving the aerodigestive tract causes aerosolization, which increases the risk of direct and cross-contamination among healthcare workers.3Zang R. Gomez Castro M.F. McCune B.T. et al.TMPRSS2 and TMPRSS4 promote SARS-CoV-2 infection of human small intestinal enterocytes.Sci Immunol. 2020; 5: eabc3582Crossref PubMed Scopus (580) Google Scholar Transesophageal echocardiography (TEE), being an aerodigestive tract procedure, commonly is used in cardiac surgery to evaluate the heart and its associated structures. Even though various techniques and maneuvers are suggested in recent literature to reduce aerosolization during TEE usage, the risk of infection still persists.4Jain A. Preventing contamination during transesophageal echocardiography in the face of the COVID-19 pandemic [e-pub ahead of print].J Cardiothorac Vasc Anesth. 2020 Apr 13; (Accessed May 28, 2020)https://doi.org/10.1053/j.jvca.2020.04.011Abstract Full Text Full Text PDF Scopus (7) Google Scholar The TEE probe remains in contact with the aerodigestive tract secretions, posing a potential contamination risk to healthcare workers handling the TEE probe for imaging as well as during disinfection. Usage of a protective sleeve over the TEE probe may not avoid the virus exposure completely. Moreover, a protective sleeve over the TEE probe makes the maneuver of the probe more difficult to acquire images and also compromises the image quality. Hence, the American Society of Echocardiography recommends an alternate method for TEE to be used whenever possible in COVID-19 patients.5ASE statement on protection of patients and echocardiography service providers during the 2019 novel coronavirus outbreak.J Indian Acad Echocardiogr Cardiovasc Imaging. 2020; 4: 37Google Scholar Epicardial echocardiography (E-echo) is not an uncommon imaging modality in perioperative cardiac settings. E-echo is well known to produce high-quality images, especially of the anterior cardiac structures compared to TEE.6Stern K.W.D. Emani S.M. Peek G.J. et al.Epicardial echocardiography in pediatric and congenital heart surgery.World J Pediatr Congenit Heart Surg. 2019; 10: 343-350Crossref PubMed Scopus (6) Google Scholar, 7Kumbharathi R.B. et al.Evaluation of tricuspid and pulmonary valves using epicardial and transesophageal echocardiography—a comparative study.J Cardiothorac Vasc Anesth. 2012; 26: 32-38Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar, 8Frenk V.E. Shernan S.K. Eltzschig H.K. Epicardial echocardiography: diagnostic utility for evaluating aortic valve disease during coronary surgery.J Clin Anesth. 2003; 15: 271-274Crossref PubMed Scopus (16) Google Scholar In addition to it, epiaortic echocardiography gives more valuable information about aortic diseases perioperatively.9Demertzis S. Casso G. Torre T. et al.Direct epiaortic ultrasound scanning for the rapid confirmation of intraoperative aortic dissection.Interact Cardiovasc Thorac Surg. 2008; 7: 725-726Crossref PubMed Scopus (11) Google Scholar E-echo can be performed easily by using a transthoracic probe or TEE probe (Fig 1-3).Fig 2Epicardial left ventricular long-axis view. RVOT, right ventricular outflow tract; LVOT, left ventricular outflow tract; LA, left atrium.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 3Epicardial left ventricular basal short-axis view. RV, right ventricle; AML, anterior mitral leaflet; PML, posterior mitral leaflet.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Advantages of E-echo and epiaortic echocardiography over TEE in the midst of COVID-19 pandemic are as follows:1.There is no aerosolization with E-echo/epiaortic echocardiography.2.Usually, E-echo has been performed with a protective cover over the probe, which eliminates the direct contact of the probe with patients' body fluids. Thus, decontamination of the probe is simple and easy to perform. Further, it reduces the virus exposure to healthcare workers significantly compared to TEE.3.Except for a transparent cover over the echocardiography machine while using it for suspected/confirmed COVID-19 cases, no special preparation is needed. So, there is no significant change in image quality. Limitations of E-echo over TEE are as follows:1.Hemodynamic and rhythm disturbances can occur due to direct cardiac compression. However, it is minimal on the adult heart and can be avoided by gentle probe handling.2.Infection risks cannot be neglected, which can be minimized by sterile handling and reducing the examination duration.3.Apical views are not possible due to space constraints while using a standard epicardial probe, which can be overcome by using a TEE probe.4.E-echo may cause distraction for the surgeon, leading to prolongation of surgery. Although TEE supplanted E-echo in cardiac surgery, the COVID-19 pandemic mandates us to search for an alternative option to TEE in intraoperative cardiac imaging. Thus, E-echo can be a viable alternative to TEE during this COVID-19 pandemic. None.