ECHO 2013 / Quantifying the Left Heart (LV and LA) Basic and Advanced Measurements
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LV Systolic Function - Linear
•Linear measurement based formulas
-Teichholz (assumes LV to be sphere)
-Quinones (fractional shortening)
-Both lead to inaccuracies when regional wall motion abnormalities are present because of assumptions
LV Systolic function - Linear
•Mid-wall fractional shortening
- based on the concept that mid-wall muscle fiber contraction may better reflect intrinsic contractility than endocardial contraction
LV Systolic Function - MWFS
LV Systolic Function
•Volumetric Methods:
-Simpson’s biplane method of disks
(preferred)
-Area-Length (alternate)
-TEE or TTE
Simpson’s Biplane Method of Disks
•The method of choice as per ASE
•Volumes are calculated as the sum of each disk volume. Height of each disk is 1/20th of ventricular length. Cross sectional areas are calculated from the
4- and 2-chamber diameters (or just 4- chamber if using single plane)
Simpson’s Biplane Method of Disks
•Pitfalls
-Avoid performing on foreshortened pictures: will overestimate
-exclude trabeculations and papillary muscles from tracing
-make sure to use mitral annulus for basal border
Simpson’s Method of Disks
Area-Length
•Uses formula:
-[5 ( area x length)]/6
-cross-sectional area at mid LV SAX
-length from apex to mid-point of mitral annulus in 4 Ch view
-assumes LV to be bullet-shaped
LV Systolic Function
Reference Values