Cardiac POCUS, pt 2 Flashcards
Based on Ma and Mateer's Emergency Ultrasound, 3rd ed
The 6 E’s of Cardiac POCUS
Exertion
Effusion
Exit
-
Equality
Ejection
Entrance
How to confirm a true pulseless electrical activity (“Exertion”)
Absence of coordinated myocardial contractions and valve movement
Pooling of blood and echogenic clots in the chambers
Features of cardiac tamponade (“Effusion”)
Pericardial effusion
RA systolic collapse
RV diastolic collapse
Lack of IVC respiratory variation
Upper limit of normal of the aortic root (“Exit”)
3.5 cm
Aortic dissection may be detected by what ultrasound views?
Parasternal long-axis (PLAx)
Suprasternal view
Abdominal vew
How to perform suprasternal view
Place te transducer in the sternal notch
With the marker pointed toward the pateint’s left scapula (cardiac preset)
with transducer aimed as far anteriorly as possible
(Head is turned to the left)
Structures seen in suprasternal view
Aortic Arch
Right pulmonary artery
Left brachiocephalic vein
Left common carotid artery
3 branches of the aortic arch
Brachiocephalic artery
Left common carotid artery
Left subclavian artery
Ultrasound findings of massive PE (“Equality”)
Massive RV dilatation
*Right-sided heart failure
Small, vigorously contracting LV
McConnell’s sign
Paradoxical septal motion
Septal flatteing or D-sign
* TAPSE <17 mm (A4C view) (Tricuspid Annular Plane Systolic Excursion)
Normal right ventricular end-diastolic diameter (RVEDD)
normal right ventricular end-diastolic diameter (RVEDD)
At A4C view:
≤3.5 cm at the mid-RV
≤4.0 cm at the base
Normal RV free wall thickness
2.0 - 3.0 mm is normal.
≥5.0 mm is hypertrophied
Hypertrophied RV free wall may indicate a more chronic etiology of RV strain rather than an acute event.
Discuss EPSS (“Ejection”)
E-point Septal Separation
The first peak is the E-point (passive filling in early diastole)
The second peak is the A-point (caused by atrial contraction)
This double peak is evidence of sinus rhythm
≤6 mm: normal left ventricular function
>7 mm: EF <50%
≥13 mm: EF ≤35%
optimal method to measure left ventricular ejection fraction
Using the method of discs (modified Simpson’s rule)
Calculation of LV EF by the method of disks will be inaccurate if true apical views are not obtained and foreshortened (oblique) views of the LV are measured.
The most efficient method for estimating left ventricular ejection fraction
Visual estimation
Stroke volume can be measured by obtaining these 2 variables:
(1) the area of the LVOT
(2) the velocity time integral (VTI) of the flow through the aortic valve during systole
How to determine left atrial enlargement?
by measuring the end-systolic atrial diameter in the parasternal long-axis view.
>4 cm, or if significantly larger than the aortic root –> LAE
This is suggestive of LVH
LV internal chamber diameter >5.5 - 6.0 cm
or wall thickness ≥12 mm,
measured at the end of diastole
Normal LV:
Conoid shape, pointed apex
*Wall thickness 0.6 - 0.9 cm (<1 cm)
IVC is measured where? (“Entrance”)
about 3-4 cm distal to its junction with the atrium
or 2 cm distal to the entry of the hepatic veins
standard definition of fluid responsiveness
> 15% increase in cardiac output with a fluid bolus (500 - 1000mL)
Ultrasound indicators of hypovolemia
Hyperdynamic LV
LV systolic collapse
IVC collapsibility
Remarks on IVC assessment
From a practical standpoint, the initial size and respiratory variation in the IVC are not as helpful (except in extremes) as the changes that occur in these parameters in response to a fluid challenge.
Heart axes
The long axis of the heart is more horizontal in short obese patients
and more vertical in tall thin patients
Often the most useful view for point-of-care cardiac ultrasound
the subcostal views
- does not interfere in resuscitative measures such as thoraxostomy, CPR, subclavian line insertion, or endotracheal intubation
What to do if with poor-quality images on subcostal view?
Appropriate amount of utz gel,
Shallow angle to the chest wall,
Moving the transducer to the right to use the left lobe of the liver as a window and to avoid gas-filled stomach
In have patient inspire deeply, or intubated patients, you may increase the tidl volumeand
moving off the xipohoid and over the lower intercostal spaces to image the barrel-chested patient with larger A-P diameter
the short-axis view at the level of the papillary muscles is an important view because
it allows identification of the different walls of the left ventricle
Structure seen in Mercedez Benz View
Aortic Valve (Mercedes Benz Sign)
Left atrium
Right atrium
TV, RV, PV
remarks on doing the apical veiw
whenever possible, place the patient in the left lateral decubitus position to reduce lung artifact and to bring the heart closer to the chest wall
the apical view is advantageous for
assessing LV function
and relative chamber sizes
