Cardiac arrest, dyspnea, chest pain, syncope, palpitations, shock
Cardiac / Phased Array / Sector probe
- ORIENTATION: this is by far one of the most difficult aspects of mastering point-of-care echo. When in the cardiac setting (the indicator is on the RIGHT side of the screen/the patient's LEFT - this is the opposite of our typical scanning convention) place the probe indicator marker towards the BASE of the heart or the Left Ventricle. For example, in a PSLA (parasternal long axis) view, the indicator is towards the base which is the patient's right shoulder. In an A4C view, place the indicator toward the left ventricle which is the patient's axilla. It's easier to think of the cardiac exam in terms of a clock, indicator towards 10:00 in PSLA, 2:00 for PSSA and 3:00 for A4C. For more background on this convention, click here.
- PATIENT POSITIONING: Lift the patient's arms above their head to maximize intercostal windows, turn them into the left lateral decubitus position to bring the heart closer to the chest wall and displace the left lung. For subxyphoid views, the patient can bend their knees to relax their abdominal musculature, you'll need to change your grip and place the probe FLAT against their epigastric region.
Views and Measurements
- *Parasternal Long Axis (PSLA): should visualize the LA, LV, MV and LVOT.
- Estimating EF: Look for gross wall motion abnormalities and MV anterior leaflet excursion. Here you can measure the E-Point Septal Separation (EPSS), and describe LV function as hyperdynamic (EF>70%), Normal (EF 50-70%), Reduced (30-50%), Severely Reducted ( <30%)
- *Parasternal Short Axis (PSSA): should visualize the MV ("fishmouth"), the papillary muscles, and the AV ("mercedes-benz" sign).
- "D sign" for RV strain, Regional Wall Motion Abnormalities (RWMA)
- *Apical 4 Chamber (A4C): should visualize the RA, TV, RV and the LA, MV, LV, with the septum vertically oriented.
- RV dilation: the RV:LV ratio should be <0.6, a ratio above 1.0 suggests severe RV strain
- *Subxyphoid: visualize all 4 chambers + the anterior and posterior pericardium
- Pericardial Effusion: the sum of the anterior/posterior pocket diameters. Trace/physiologic should disappear in diastole, small < 1 cm, moderate 1-2 cm, large > 2cm.
- *IVC: to assess volume status - M-mode marker placed about 2 cm from RA at hepatic vein
- > 50% inspiratory collapse correlates with CVP of <10mm Hg
- <50% inspiratory collapse corrlates with CVP of >10mm Hg
Can help differentiate hypovolemic and cardiogenic shock and guide fluid resuscitation. CAVEAT: a plethoric IVC is also seen in many disease states (pulmonary hypertension, PE, tamponade, severe tricuspid regurgitation, RV failure, etc.) even when the patient is intravascularly dry. It's critical to only evaluate the IVC in the context of a full echo.
- Apical 2 chamber (A2C)
- Apical 3 chamber (A3C) 3rd chamber is the aorta, this is simply a modified A2C
- Apical 5 chamber (A5C) 5th chamber is the aorta, this is simply a modified A4C
- Suprasternal view (good for aortic arch visualization)
- Use color doppler to evaluate for regurgitant jets and incompetent heart valves
- * Indicates a REQUIRED view