Cardiac ultrasound

Background

• Important to realize that the cardiac ultrasound preset on some machines reverses the indicator marking with the probe indicator on the right
• With the general ED ultrasound the probe indicator is on the left of the screen

Indications

• Shock
• Chest pain
• Shortness of breath

Technique

1. Select probe
   • Phased array probe
2. Location

Parasternal Long

• Pointer to right shoulder, probe at left 3rd/4th intercostal space adjacent to sternum
• Use to visualize global function and rule out pericardial effusion/tamponade
  • Can evaluate mitral valve, aortic valve, aortic root, LV squeeze

Parasternal Short

• Pointer to left shoulder, probe at left 3rd/4th intercostal space adjacent to sternum
• Tip: obtain parasternal long view, then rotate probe 90 degrees
• Use to evaluate LV squeeze, right ventricle
  • Right heart strain = dilated right ventricle

Apical 4 chamber

• Pointer to right, usually below nipple
• Use to visualize global function (Left and right ventricle, squeeze)
• Use this view to obtain the Tricuspid Annular Plane Systolic Excursion (TAPSE)
  • Represents the distance the tricuspid annulus moves longitudinally toward the apex during systole
  • Measurement obtained using M-Mode with the tracer line through the lateral tricuspid annulus
  • < 16mm is suggestive of right heart dysfunction

Subxyphoid

• Pointer to right, subxyphoid with probe pointed toward head
• Use liver to as acoustic window to visualize heart

Suprasternal (Optional)

• Pointer at 12 o'clock (cephalad) and place in sternal notch
• Move probe inferior and to the left to visualize aortic arch
• Rotate probe clockwise for further image optimization
  • Can evaluate for aortic dissections/aneurysms, coarctation of the aorta, and aortic stenosis/regurgitation

Apical 5 chamber (optional)

• Start in the Apical 4 chamber view, tilt the probe upwards until the aortic outflow tract is seen
• This view can be used to calculate the velocity time integral (VTI) and subsequently cardiac output to assess fluid responsiveness

Apical 3 chamber (optional)

• Start in the Apical 4 chamber view, rotate the probe until the marker points towards the patient's right shoulder
• This view can be used to calculate the velocity time integral (VTI) and subsequently cardiac output to assess fluid responsiveness (alternate method to the apical 5 chamber view)

Findings

Classic Ultrasound Findings For Critically Ill Patients

Disease	Cardiac	IVC	Lung (Phased Array)	Lung (Linear)
MI	Focal WMA Mod/Poor squeeze	↑	NL or B-lines	Sliding
Tamponade	RA collapse with filling RV collapse with filling	↑	NL	Sliding
pneumothorax	NL or Hyperdynamic	↑	Lung point Consolidated lung	Absent lung sliding
Sepsis	Hyperdynamic squeeze	↓	NL (see pneumonia)	Sliding
Pneumonia	Hyperdynamic squeeze	NL or ↓	Unilateral B-lines	Sliding
Decompensated HF	Mod/Poor squeeze	↑	Bilateral B-lines	Sliding
PE	RV > LV McConnell's sign	↑	NL or Unilateral B-lines	Sliding

Parasternal Long

• Assess for pericardial effusion and differentiate from pleural effusions
• Assess ejection fraction using E-point septal separation (EPSS)
  • Measures the distance between the maximal opening of the anterior leaflet of the mitral valve during diastole (the E wave) and the septum
  • Measured using M mode
  • EPSS > 7mm is 100% sensitive for EF < 30%
• Fractional shortening for LVEF estimation
  • Place M-mode marker perpendicular to LV cavity
  • Measure LV end diastolic diameter (LVEDD) and LV end systolic diameter (LVESD)
  • Calculate LVEF using %FS = (LVEDD-LVESD)/LVEDD×100%

Parasternal Short

• Assess for pericaridal effusion
• Assess for squeeze - visual estimate of hyperdynamic, good, moderate, or poor
• Can also assess fractional shortening in short axis at level of papillary muscles (see above for calculation)

Apical 4 chamber

• Assess RV:LV diameter at the level of the valves
  • Normal RV:LV is 0.6:1
  • RV strain is >1:1
• Assess for McConnell's sign
• Calculate TAPSE using M-mode

Subxyphoid

• Assess for pericardial effusion
• If concerns for PE, assess for right ventricular wall diameter in end diastole
  • Diameter of <5mm is suggestive of acute pulmonary hypertension
  • Diameter of >5mm is suggestive of chronic pulmonary hypertension

Suprasternal (Optional)

• Assess for aortic dissection

IVC ultrasound

• Tyically included in interpretation

Images

Documentation

Normal Exam

A bedside ultrasound was conducted to assess the heart with clinical indications of SOB. The parasternal long, parasternal short, apical four chamber, subxyphoid, and IVC views were obtained. Normal diameter AOFT, no pericardial or pleural effusions identified, good squeeze, RV<LV, and IVC was not plethoric nor flat. Normal cardiac ultrasound.

Abnormal Exam

A bedside ultrasound was conducted to assess the heart with clinical indications of SOB. The parasternal long, parasternal short, apical four chamber, subxyphoid, and IVC views were obtained. Normal diameter AOFT, EPSS >7mm, no pericardial effusion, bilateral pleural effusions, poor squeeze, RV<LV, and IVC was plethoric. Indicative of systolic heart failure.

See Also

• Ultrasound (Main)
• Formal echocardiography
• Pericardial Effusion and Tamponade

External Links

EMRA: Fractional Shortening

EMRA: EPSS

Videos

{{#widget:YouTube|id= 4qerzEW_ASU}}

{{#widget:YouTube|id= EaLuCBXXINg}}

{{#widget:YouTube|id= _eHZz-OCc_M}}

{{#widget:YouTube|id= 1UJ6RodOSTw}}