Bedside Ultrasound

Advanced Cardiac

• Assess

  • Pericardial effusion

  • Ejection fraction

  • Right heart strain

• Consider circle survey (move around in circles) to find better window

• Parasternal Long-Axis

  • Along sternal border at 3rd-6th ICS (can begin at nipple line), marker right shoulder

    • Ideal for LV ejection fraction, suspect dysfunction if any of the three following:

      • Fractional shortening ([LVIDd-LVIDs]/LVIDd) <30% = LV systolic dysfunction (measured at papillary chordae mid-LV endocardium to endocardium)

      • LV dilation >5.2cm

      • EPSS (E-Point Septal Separation) >7mm suggests reduced LVEF <30%

        • Measure distance from mitral valve to septum, average several measures, and be aware that valvulopathy may affect value

    • Effusion posterior to aorta = pleural effusion (anterior = pericardial)

• Parasternal Short-Axis

  • 3rd-5th ICS , marker to left shoulder 

  • Aorta (Mercedez Benz sign) -> Mitral -> Apex

    • Ideal for pericardial effusion, and wall-motion abnormalities

• Apical four chamber

  • Apex (usually 1-2 ICS below left nipple), marker to right flank and aim beam to right shoulder (may ask patient to lie on left side)

    • Ideal for RV strain

      • RV >2/3 LV consider R heart strain

    • Measure TAPSE (Tricuspid Annular Plane Systolic Excursion) to evaluate RV dysfunction

      • M-mode cursor through lateral tricuspid annulus plane, measure lowest to highest point (trough to nadir)

        • Ensure measuring parallel to movement of annulus

        • TAPSE <17mm indicates right ventricular systolic dysfunction (normal ≥1.7 cm)

          • TAPSE <17.5mm is 87% sensitive and 91% specific for RV dysfunction

          • DDx: Pulmonary hypertension, heart failure, pulmonary embolism, ischemic heart disease (inferior and RV MI)

        • Differentiating Acute vs. Chronic RV dysfunction 

          • RV free wall thickness 

            • Normal (or acute RV dysfunction) <4 mm

            • At 48h, can see thickening 4-8mm

            • Chronic >10mm

          • PASP (Pulmonary Artery Systolic Pressure)

            • In Apical 4 or PSS axis view, place color doppler over Tricupsid Valve and RA, look for triscupid regurgitatant jet (blue)

              • Align doppler beam with jet, toggle CW mode to spectral display (press colour a second time) to calculate maximum TR velocity (V = VTR Max)

                •  Use the Modified Bernoulli equation to calculate the pressure gradient (∆P) across the tricuspid valve: ∆P=4*VTR Max^2

                • RVSP =4*VTR Max^2 + CVP (see below for CVP estima tion with IVC)

                • Estimate CVP with IVC : 3 if normal, 8 if >2.1cm diameter OR <50% collapsible , 15 if >2.1cm diamter AND<50% collapsible

              • PASP ≈ RVSP if no significant pulmonary valve stenosis

          • McConnell's sign (apical sparing) is indicative of acute RV strain

    • Measure MAPSE

      • M-mode over medial mitral annulus plane, measure lowest to highest point (trough to nadir)

      • ≥10 mm preserved ejection fraction

      • <8 mm  suggests LV EF <50%

      • <7 mm suggests LV EF  <30%

IVC

• Long axis IVC

  • Subxiphoid, marker to head

    • Consider assessing "size" at around 1cm for hepatic vein or 2-3cm from RA

      • Consider flat and collapsible (>50% collapsibility with respiration) vs. full and fixed (>2.5cm)

• Note: No consensus for measurements, sniff test not validated, unlikely helpful for fluid-responsiveness

• May be useful with cardiac/lung views to differentiate causes of shock

  • PTX = Absent lung sliding /  N or  ↑ contractility / ↑ IVC 

  • Distributive (Sepsis/Anaphylaxis) =  ↑ contractility / ↓ IVC 

  • MI/CHF =  Cardiac contractility / ↑ IVC / B-lines

  • Tamponade =  RA/RV collapse, pericardial effusion / ↑ IVC 

  • PE = RV strain (RV>LV) / ↑ IVC 

    • McConnell's sign: Akinesia of the RV mid free wall but normal motion at the apex