Transcript Left Ventricular Function

CARDIAC ULTRASOUND
Turandot Saul, M.D., RDMS
St. Luke’s Roosevelt Hospital
New York, NY
Cardiac Windows
Cardiac Windows
 Subxiphoid
 Parasternal long axis
 Parasternal short axis
 Apical 4 chamber
Ultrasound probe
Low Frequency Curved Array
Subxiphoid
 Under costal margin
 Marker to patient’s right
 Shallow angle (15°)
 Liver as acoustic window
 Bend knees
 Deep inspiration
 FAST exam
Parasternal Long Axis
 Marker to left hip
 4th intercostal space
 Left sternal boarder
Parasternal Short Axis
 Marker to right hip
 4th intercostal space
 Left sternal boarder
Apical 4 Chamber
 Left lateral decubitus
 PMI
 Marker to right hip
 Aim towards right
shoulder
Yes / No Questions
Wall Motion?
 B -mode
Yes or no?
Wall Motion?
 M –mode
 More accurate
Wall Motion Using M-mode
Asystole
Ventricular
Contractions
Yes / No Question
CC:
Shortness of Breath
Emergency Echo
Pericardial Effusion
 Fluid lays dependently
 Adjust depth to fit on screen
 Image in 2 views
Cardiac Function
Systole
Left Ventricular Function
 Fills at low enough pressures to not cause
pulmonary congestion
 Deliver enough blood to periphery at high
enough pressure to perfuse tissues
No one quantity measures these
assessments of performance
Ejection fraction
Ultrasound for LV Function
Strengths
 Can assess morphology
 Cheap
 No radiation
 Portable
 Readily available
Ultrasound for LV Function
Limitations
 Finding an acoustic window
- narrow inter-costal spaces
- all regions of LV not visualized in all patients
- obesity
- intervening lung tissue in pt with COPD
- musculoskeletal deformities
Ejection Fraction
• Qualitative - visual inspection
- severity: mild, moderate, severe
- focality
- global: reported in intervals of 510%
- regional: 17 segments
Global Function
Normal
Cardiomyopathy
Global Function
Normal
Cardiomyopathy
17 Cardiac Segments
CC:
Chest Pain
Inferior Wall - PSLA
Inferior Wall - PSSA
CC:
Chest Pain
Anterior Wall - PSLA
Anterior Wall - PSSA
CC:
SOB 3 weeks later
Emergency Echo
Ejection Fraction
• Quantitative
- accuracy, reproducibility limited
- assumes symmetric shape of LV cavity
Simpson’s Rule – the biplane method
of disks
 Volume left ventricle
LV-ED
LV-ES
- trace in systole and diastole
- divide area into disks
Σ volume of each disk ( πr2 * h ) =
ventricular volume
Simpson’s Rule – the biplane
method of disks
 EF is calculated :
LV diastolic volume - LV systolic volume
LV diastolic volume
Normal > 50%
35 - 50% moderately depressed
<35% severely depressed
 Edge detection software
x 100%
Superiority of Visual Versus Computerized
Echo Estimation of Radionuclide LVEF
- Amico, A. American Heart Journal, 1989
 Blinded study, 44 patients
 Gold Standard - equilibrium radionuclide
angiography (ERNA)
 7 different echocardiographic methods
 Best correlation - subjective estimation by
experienced cardiologist
Accuracy of Emergency Physician Assessment
of Left Ventricular Ejection Fraction
– Randazzo, M. Academic Emergency Medicine, 2003
 Cross-sectional observational study, convenience sample
 115 patients
 Three-hour training session
 LVEF poor, moderate, or normal
 Formal echo within four hours interpreted by cardiologist
 LVEF correlation 86.1% overall agreement
 Highest (91%) in normal LVEF category, 70.4% poor LVEF,
47.8% moderate LVEF
Clinical utility
 Patients with active chest pain
- regional wall motion abnormality
- high sensitivity for ischemia or infarction
- moderately specific
 Prognostic information short and long term
Limitations
 Operator dependence
- inter/intra observer variability is 10-30%
 Limited utility
- MR high EF but little forward flow
- AS low EF but possibly reversible
Diastole
CC:
SOB, long hx of HTN
Emergency Echo
Diastolic Dysfunction
 Impaired diastolic relaxation
 LV wall thickness usually increased
 Increase LA size
Other Pathology
CC:
SOB, transatlantic flight
Emergency Echo
Right Ventricle
 Increased pulmonary vascular resistance
- right ventricular dilation
 Limited accuracy in the diagnosis of PE
 Trans-esophageal echocardiography:
sensitivity for central PE 82%
CC:
Fever / chills
CC:
20 yo with Syncope
CC: Progessive SOB, Syncope
Reources

UptoDate: Noninvasive methods for measurement of left ventricular systolic function

Zipes: Braunwald’s Heart Disease: A Textbook of Cardiovascular Diseases. Elsevier Inc, 2007.

Directed bedside transthoracic echocardiography: preferred cardiac window for left ventricular
ejection fraction estimation in critically ill patients. American Journal of Emergency Medicine Volume 25, Issue 8 (October 2007) - Copyright © 2007 W. B. Saunders Company

Accuracy of emergency physician assessment of left ventricular ejection fraction and central
venous pressure using echocardiography. Randazzo MR - Acad Emerg Med - 01-SEP-2003; 10(9):
973-7

Determination of left ventricular function by emergency physician echocardiography of
hypotensive patients.
Moore CL - Acad Emerg Med - 01-MAR-2002; 9(3): 186-93

Subjective visual echocardiographic estimate of left ventricular ejection fraction as an alternative
to conventional echocardiographic methods: comparison with contrast angiography.
Mueller X - Clin Cardiol - 01-NOV-1991; 14(11): 898-902

Superiority of visual versus computerized echocardiographic estimation of radionuclide left
ventricular ejection fraction.
Amico AF - Am Heart J - 01-DEC-1989; 118(6): 1259-65

The Yale Atlas of Echocardiography
http://www.med.yale.edu/intmed/cardio/echo_atlas/contents/index.html