New online pharmacy, where you can purchase prednisolone whithout prescription fast and secure!

INFECTIVE ENDOCARDITIS

Patients admitted to intensive care units often have fevers and positive blood cultures.  One of the concerns associated with confirmed bacteremia is the presence of endocarditis as a consequence of the bacteremia, or even as the source. This is especially true of the organisms grown on blood cultures have a preponderance to form vegetations on cardiac valves. 

They may also present with life-threatening refractory heart failure, strokes, mesenteric ischemia and critical limb ischemia.

Here we delve into the basic principles of infective endocarditis assessment. Given several nuances with making this diagnosis (e.g. native vs. prosthetic valves, presence of aortic root abscesses, etc.), when in doubt, consult with your local echocardiographer.

Given there are 4 main native valves (aortic, mitral, tricuspid, pulmonic) of the heart, they can become infected (e.g. bacterial, fungal, marantic, etc.), with a diagnosis known as endocarditis.

We will overview the principles of endocarditis interrogation, including:

  • Views (mid-esophageal 4-chamber, mid-esophageal long-axis, RV inflow-outflow, deep trans-gastric apical 5-chamber views)
  • Sweeping of the valve (to interrogate for IE)
  • Assessment/measurement of vegetations
  • Colour and spectral Doppler interrogations
  • Determining valvular endocarditis sequelae

2D/COLOUR/SPECTRAL DOPPLER/SWEEPING

  • We interrogate all valves of endocarditis with the following principles:
    • 2D structures:
      • Focus on the valve of interest
      • Zoom in on the valve structure
      • Sweep through the valve structure (by turning the probe clock-wise and counter-clockwise, and pulling/pushing the probe inward/outward or up/down) to ensure that the assessment for vegetations is THOROUGH 
      • Capture still images of the vegetation (caliper measurements)
  • Colour Doppler
    • Turn on colour box – keeping the Nyquist limit to:
      • High [~60-70cm/s] – for looking at regurgitant lesions
      • Remember to place the colour box across the valve, and have the box big enough to interrogate the entire chamber where regurgitation occurs
  • Spectral Doppler (continuous wave [CW])
    • Place CW across the center of most of the valve structure (to assess both for stenotic and regurgitant lesions)
    • AI CW assessed from deep TG A5C
    • MR and TR assessed best from ME4C

Assessment/measurement of vegetations

  • The best windows to assess for IE:
    • AV: ME LAX (~120 degrees)
    • MV: ME 4C (~0 degrees)
    • TV: ME 4C (~0 degrees)
    • PV: ME RV Inflow/Outflow or ME AV SAX (~60-90 degrees)
  • Vegetations can be measured using calipers (still image)
  • Large, mobile vegetations (>1cm) are considered higher risk for embolism (potential for earlier surgical decision)
  • Vegetations with INCREASED dimensions on serial TEE despite antimicrobial therapy = sign of UNCONTROLLED infection
  • TEE  is  the  method  of choice  for  measuring  the  size of  the  vegetation  and for  follow-up.

Colour and spectral Doppler interrogations

  • Vena contracta (VC): width of the regurgitant jet size –  approximates regurgitant orifice
    • Measure where the flow across the valve is preceded by a convergence zone – followed by a widening jet (hourglass appearance)
    • Tiny measurement – small errors lead to big discrepancies in severity
    • Not useful when multiple jets present
    • Mild: < 3mm, moderate: 3-7mm, severe: >7mm (remember to ZOOM on STILL image of colour)
  • Regurgitant lesions (colour/Spectral cutoffs):
    • Severe AI: colour occupies >65% of LVOT, diastolic flow reversal seen in descending aorta
      • Pressure half-time (PHT): CW
        • Mild: >500ms
        • Moderate: 200-500ms
        • Severe: <200ms
  • Severe MR: colour occupies >40% of LA, pulmonic vein flow reversal during systole, jet hits back wall of LA (e.g. Coanda effect)
  • Severe TR: colour occupies > 40% of RA, jet hits back wall of LA, hepatic vein flow reversal during systole
  • Severe PI: large colour jet width, brief duration, dense steep deceleration, early termination of diastolic flow, greatly increased pulmonary flow
    • Pressure half-time (PHT): CW
      • Mild: >1100ms
      • Moderate: 570-1100ms
      • Severe: <570ms

Determining valvular endocarditis sequelae

  • Vegetations  are  typically attached  on  the  low-pressure side  of the valve, but may be located anywhere on the valve or sub-valvular structure, mural endocardium, cardiac chambers, or aorta
  • When   large   and   mobile (> 1 cm),   vegetations  are more prone  to  embolism
  • Destructive  valve  lesions  are  very  frequently  associated  with vegetations (but can still be observed alone). 
  • They  may  provoke valve aneurysm, perforation, prolapse, chordae/papillary muscle rupture 
  • The usual final consequence of these lesions is severe valve regurgitation & heart failure 
  • Another anatomical  feature  of  IE  is  abscess  formation (Abscesses   are   more   frequent   in   aortic   and   prosthetic IE, and   may   be   complicated  by   pseudoaneurysm   or fistulization)

INFECTIVE ENDOCARDITIS TUTORIAL

In this tutorial, we will breakdown performance and interpretation of IE interrogation.

references

  1. Habib G, (France), Badano L, et al.: Recommendations for the practice of echocardiography in infective endocarditis [Internet]. Eur J Echocardiogr 2010; 11:202–219[cited 2021 Oct 3] Available from: https://academic.oup.com/ehjcimaging/article-lookup/doi/10.1093/ejechocard/jeq004
  2. Otto CM, Nishimura RA, Bonow RO, et al.: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines [Internet]. Circulation 2021; 143:e72–e227[cited 2021 Oct 3] Available from: https://www.ahajournals.org/doi/10.1161/CIR.0000000000000923
  3. Mayo PH, Beaulieu Y, Doelken P, et al.: American College of Chest Physicians/La Societe de Reanimation de Langue Francaise statement on competence in critical care ultrasonography [Internet]. CHEST J 2009; 135:1050–1060[cited 2017 Jan 16] Available from: http://journal.publications.chestnet.org/article.aspx?articleid=1089755
  4. Mayo PH, Narasimhan M, Koenig S: Critical Care Transesophageal Echocardiography [Internet]. CHEST 2015; 148:1323–1332[cited 2018 Feb 6] Available from: http://journal.chestnet.org/article/S0012-3692(15)50244-4/abstract
  5. Teran F, Prats MI, Nelson BP, et al.: Focused Transesophageal Echocardiography During Cardiac Arrest Resuscitation: JACC Review Topic of the Week. J Am Coll Cardiol 2020; 76:745–754
  6. Teran F, Burns KM, Narasimhan M, et al.: Critical Care Transesophageal Echocardiography in Patients during the COVID-19 Pandemic [Internet]. J Am Soc Echocardiogr 2020; 33:1040–1047[cited 2021 Apr 7] Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7245221/
  7. Lau V, Priestap F, Landry Y, et al.: Diagnostic Accuracy of Critical Care Transesophageal Echocardiography Versus Cardiology-Led Echocardiography in Intensive Care Unit Patients [Internet]. CHEST 2018; 0[cited 2018 Dec 15] Available from: https://journal.chestnet.org/article/S0012-3692(18)32856-3/abstract
  8. Jaidka A, Hobbs H, Koenig S, et al.: Better With Ultrasound: Transesophageal Echocardiography [Internet]. Chest 2019; 155:194–201[cited 2021 Oct 3] Available from: https://www.sciencedirect.com/science/article/pii/S0012369218325637
  9. Millington SJ: Cardiac Ultrasound Is a Competency of Critical Care Medicine [Internet]. Crit Care Med 2017; 45:1555–1557[cited 2021 Oct 3] Available from: https://journals.lww.com/ccmjournal/Fulltext/2017/09000/Cardiac_Ultrasound_Is_a_Competency_of_Critical.18.aspx?casa_token=Eiszcty1GEMAAAAA:WG0_9xjkMsY_b6TBbLwoicYGdgU3rho50MF9YkACZa1vsp5s46PNHGFOLoQMjG-hsWPk8P8IUTDXYT8BicduyIYjb0O0
  10. Douglas PS, Garcia MJ, Haines DE, et al.: ACCF/ASE/AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011 Appropriate Use Criteria for Echocardiography: A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Society of Echocardiography, American Heart Association, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Critical Care Medicine, Society of Cardiovascular Computed Tomography, and Society for Cardiovascular Magnetic Resonance Endorsed by the American College of Chest Physicians [Internet]. J Am Coll Cardiol 2011; 57:1126–1166Available from: http://www.sciencedirect.com/science/article/pii/S0735109710044694
  11. Douglas PS, Khandheria B, Stainback RF, et al.: ACCF/ASE/ACEP/ASNC/SCAI/SCCT/SCMR 2007 Appropriateness Criteria for Transthoracic and Transesophageal Echocardiography: A Report of the American College of Cardiology Foundation Quality Strategic Directions Committee Appropriateness Criteria Working Group, American Society of Echocardiography, American College of Emergency Physicians, American Society of Nuclear Cardiology, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, and the Society for Cardiovascular Magnetic Resonance Endorsed by the American College of Chest Physicians and the Society of Critical Care Medicine [Internet]. J Am Soc Echocardiogr 2007; 20:787–805[cited 2018 Feb 6] Available from: http://www.onlinejase.com/article/S0894-7317(07)00483-X/abstract
  12. Expert Round Table on Echocardiography in ICU: International consensus statement on training standards for advanced critical care echocardiography. Intensive Care Med 2014; 40:654–666
  13. Expert Round Table on Ultrasound in ICU: International expert statement on training standards for critical care ultrasonography. Intensive Care Med 2011; 37:1077–1083
en_USEnglish
en_USEnglish