Right Ventricular Function and Echo
CHAMBER SIZE
- N.B. Given the complex geometry of the RV and the retrosternal nature of the same, chamber size measurements are HIGHLY prone to significant amounts of error
- RV enlargement is suggested if:
- RV area dimension is larger than LV area in end-diastole in the AP4C (apical four)
- A linear basal dimension of >4.2cm is also suggestive of significant enlargement
- Like all echo imaging — need to look in multiple windows, to ensure accurate findings
- the RV chamber is normally a crescent curving in front of LV
WALL THICKNESS
- RV hypertrophy from pressure overload (chronic) where the thickness at end-diastole is >5mm (best seen in subcostal views)
RV FUNCTION
- Normal function is restricted mainly to longitudinal (base to apex) shortening and systolic thickening
- Systolic function:
- TAPSE (Tricuspid Annular Plane Systolic Excursion) normal is >1.7cm (less useful post some cardiac surgery) [measured in AP4C w/ M Mode]
- RVFAC (RV Fractional Area Change) normal is >35% [measured in AP4C]
- Diastolic function measured with tissue doppler:
- Tricuspid annulus (E) and early diastolic tricuspid inflow (E’) ratio (E/E’) measured in patients with PH
- Can be difficult to assess due to shape, trabeculations
- May require TOE
- RWMA is sensitive and specific for RV ischaemia or infarction
PULMONARY ARTERY SYSTOLIC PRESSURE (PASP)
- some TR is normal
- In the absence of RVOT obstruction: RVSP = PASP
- RV systolic pressure = RAP + transtricuspid gradient (from peak tricuspid regurgitation velocity)
OTHER
- TAPSE / PASP ratio may be a good marker of RV-PA coupling (or uncoupling) as TAPSE reflects RV contractile function and PASP is a surrogate for afterload
- TAPSE/PASP ratio normally >0.31mm/mmHg
- A ratio of <0.31mm/mmHg was predictive of patients having a significantly worse prognosis than those with higher ratios
RV DILATION MAY BE DUE TO:
- Acute or Chronic RV Failure
- Large PE
- Pulmonary Hypertension
- Volume Overload
- TR (leading to volume overload) –> ‘auto-aggravation’
- ASD
- PR / PS
- RV myocardial infarction
ECHO FEATURES OF RV FAILURE
- RV dilation (can grossly compare w/ LV size on AP4C)
- Diastolic interventricular septal flattening (left-ward shift) = volume overloaded state
- Systolic interventricular flattening (left-ward shift) = pressure overloaded state
- RV hypokinesis (mild, moderate, severe)
- Hepatic vein flow reversal indicates severe TR
- Left-ward interatrial septal bowing also indicates increased RAP / volume overload
- IVC diameter / collapsibility with respiration (or lack thereof) may be indicator of volume overload
References and Links
- Burgess MI, Bright-Thomas RJ, Ray SG. Echocardiographic evaluation of right ventricular function. Eur J Echocardiogr. 2002 Dec;3(4):252-62. PMID: 12413440. [Free Fulltext]
- ICU Sonography — Assessment of the right heart
- Konstam MA, Kiernan MS, Bernstein D, Bozkurt B, Jacob M, Kapur NK, Kociol RD, Lewis EF, Mehra MR, Pagani FD, Raval AN, Ward C; American Heart Association Council on Clinical Cardiology; Council on Cardiovascular Disease in the Young; and Council on Cardiovascular Surgery and Anesthesia. Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association. Circulation. 2018 May 15;137(20):e578-e622. doi: 10.1161/CIR.0000000000000560. Epub 2018 Apr 12. PMID: 29650544. [Free Full Text]
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Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
ICU Advanced Trainee BMedSci [UoN], BMed [UoN], MMed(CritCare) [USyd] from a broadacre farm who found himself in a quaternary metropolitan ICU. Always trying to make medical education more interesting and appropriately targeted; pre-hospital and retrieval curious; passionate about equitable access to healthcare; looking forward to a future life in regional Australia. Student of LITFL.