Quick-Hit Ultrasound Probe: Regional Wall Motion Abnormalities

Author: Steven Field, DO (EM Attending Physician, UT Southwestern Medical Center / Parkland Memorial Hospital) // Edited by: Stephen Alerhand, MD (@SAlerhand – EM Resident Physician and Incoming Ultrasound Fellow, Icahn School of Medicine at Mount Sinai) and Manpreet Singh, MD (@MPrizzleER – Assistant Professor in Emergency Medicine / Department of Emergency Medicine – Harbor-UCLA Medical Center)



Background

On every shift, diagnosing and risk stratifying patients with acute coronary syndromes (ACS) is a challenge. Whereas bedside ultrasound can help rule out diagnoses like pneumothorax, pericardial tamponade, pneumonia, and pleural effusions, there are patients with regional wall motion abnormalities on echocardiograpgy (representing areas of imminent ischemic death) who can benefit from early invasive intervention (angiography and coronary stenting).

The ACA/AHA guidelines for managing UA/NSTEMI recommend (Class 1A recommendation) early invasive strategies for those patients with elevated risk for clinical events—one of those risk factors being abnormal findings on echocardiography.(3) Echocardiography to assess for regional wall motion abnormalities is recommended in patients with a clinical history and physical exam concerning for acute coronary occlusion, in whom EKG is equivocal and biomarkers negative. It has been shown that global and regional wall motion abnormalities can be accurately identified on bedside echocardiogram by emergency physicians in the ED.(5) These findings may help avoid delay in getting patients to the cath lab and thus save myocardium.


EKG

The goal on bedside echo is to identify an area of affected myocardium in the distribution of coronary blood flow that is occluded. The EKG below demonstrates the typical coronary artery distributions:

– Blue = lateral wall = circumflex artery
– Yellow = inferior wall = right coronary artery
– Red = anterior wall = left anterior descending artery


Echo

Echocardiographers divide up the left ventricle into 17 different segments. Emergency physicians typically differentiate between only three segments. The EKG distributions above correspond to areas of affected myocardium (see diagrams alongside echo clips). These are characterized as normal, hypokinetic, and akinetic.

 

 

 

For a further detail viewing of these segments relating to vascular territories, please see the following image:

Cerqueira M.D., Weissman N.J., Dilsizian V., Jacobs A.K., Kaul S., Laskey W.K., et al. Standardized myocardial segmentation and nomenclature for tomographic imaging of the heart: a statement for healthcare professionals from the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart Association. Circulation (2002) 105:539–542

See this outstanding vodcast by Felipe Teran MD and Lara Vanyo MD.


Case

55 y/o M with h/o HTN and NIDDM presents with 2 hours of exertional chest pain. He appears uncomfortable but is hemodynamically stable. The EKG shows symmetrical T-wave peaking in the inferior leads but nothing meeting STEMI criteria. The first troponin is negative. On his bedside echo (clips below), he has an inferior septal area of hypokinesis that is consistent with an RCA lesion. The Cardiology consultant is called to the ED, reviews the images, and the patient is subsequently taken to the cath lab where a 90% unstable RCA thrombus is found.

 

 


Sources

  1. Esmaeilzadeh M, Parsaee M, Maleki M. The Role of Echocardiography in Coronary Artery Disease and Acute Myocardial Infarction. J Tehran Heart Cent. 2013 Jan;8(1):1-13.
  2. Barnett K, Feldman JA. Noninvasive Imaging Techniques to Aid in the Triage of Patients with Suspected Acute Coronary Syndrome: A Review. Emerg Med Clin North Am. 2005 Nov;23(4):977-98.
  3. Wright RS, Anderson JL, Adams CD, Bridges CR, Casey DE Jr, Ettinger SM, Fesmire FM, Ganiats TG, Jneid H, Lincoff AM, Peterson ED, Philippides GJ, Theroux P, Wenger NK, Zidar JP, Anderson JL, Adams CD, Antman EM, Bridges CR, Califf RM, Casey DE Jr, Chavey WE 2nd, Fesmire FM, Hochman JS, Levin TN, Lincoff AM, Peterson ED, Theroux P, Wenger NK, Wright RS. 2011 ACCF/AHA Focused Update of the Guidelines for the Management of Patients With Unstable Angina/ Non–ST-Elevation Myocardial Infarction (Updating the 2007 Guideline). A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines developed in collaboration with the American College of Emergency Physicians, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2011 May 10;57(19):1920-59
  4. Sabia P, Afrookteh A, Touchstone DA, Keller MW, Esquivel L, Kaul S. Value of regional wall motion abnormality in the emergency room diagnosis of acute myocardial infarction. A prospective study using two-dimensional echocardiography. Circulation. 1991 Sep;84(3 Suppl):I85-92.
  5. Kerwin C, Tommaso L, Kulstad E. A Brief Training Module Improves Recognition of Echocardiographic Wall-Motion Abnormalities by Emergency Medicine Physicians. Emergency Medicine International Volume 2011 (2011): 1-5.
  6. Role of echocardiography in acute myocardial infarction. https://www-uptodate-com.foyer.swmed.edu/contents/role-of-echocardiography-in-acute-myocardial-infarction/print?source=search_result&search=Role%20of%20e. Topic last updated August 10, 2015. Accessed on February 22, 2017.
  7. Detect Cardiac Regional Wall Motion Abnormalities by Point-of-Care Echocardiography. http://www.acepnow.com/article/detect-cardiac-regional-wall-motion-abnormalities-point-care-echocardiography/?singlepage=1. Published February 15, 2015. Accessed on February 22, 2017.
  8. Episode 7-Wall motion. http://www.ultrasoundpodcast.com/. Accessed on February 22, 2017.
  9. Interpretation of Cardiac Regional Wall Motion Abnormalities by Echocardiography – A simplified approach. http://sinaiem.us/education/regional-wall-motion-assessment/. Accessed on February 22, 2017.

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