Cardiac – NWH Emergency Medicine

INDICATIONS

Chest Pain
Shortness of Breath
Hypotension
Evaluation for right heart strain in suspected pulmonary embolism
Syncope

POSITIONING

The left lateral decubitus position will usually optimize your parasternal and apical views as the heart and left lung pull away from the sternum.

If your patient is able, breathing out will collapse the lungs and improve your view as well.

VIEWS

Parasternal Long Axis (PLAX)

The PLAX view is the “scout film” of the heart. The PLAX view plane is defined by the aortic valve, mitral valve and apex of the heart. This gives you the long axis of the heart which can guide you up to the base of the heart and the aortic valve or down to the apex.

In addition to defining the long axis of the heart, in this view you can estimate overall LV function, see pericardial effusion, assess the aortic and mitral valves, look for suggestion of right ventricular or left atrial enlargement.

Parasternal Short Axis (PSAX)

The PSAX view is obtained by rotating the probe ninety degrees from PLAX, moving the probe orientation marker from the patient’s right shoulder to left shoulder.

In this view we can optimally compare ventricular chamber sizes, assess for overall LV function or regional wall motion abnormalities and find another view of a pericardial effusion.

Apical Four Chamber (A4C)

The A4C view is obtained from the PSAX view by marching down the chest wall along the long axis of the heart with probe marker pointing to patients left.

This view provides excellent comparison of chamber sizes, assessment of RV function, assessment of tricuspid and mitral valve fuction and another view of pericardial effusions. The probe is closest to the apex and so this is a good view to assess for apical pathology (thrombus, mcconnell’s sign, etc.)

Subxiphoid (SX)

The subxiphoid view is obtained by placing the probe flat below the patient’s subxiphoid with your hand on top of the probe. Apply pressure until the heart comes into view. At times there is gas in the epigastrium which can interfere. Sometimes having the patient take a deep breath can bring the heart into view. You can also, counter-intuitively, move the probe away from the heart to the RUQ, scan through the liver as a window to th heart.

This is another view where assessment for pericardial effusion is seen but is not great for other specific assessments. The greatest utility of this view is in cardiac arrest, when the anterior chest is being used for chest compressions, defibrillations, etc.

Inferior Vena Cava (IVC)

The IVC view should be included in a complete assessment of cardiac function. This view is obtained in one of two ways. You can place the probe transversely in the epigastrium, find the IVC and Aorta and then rotate on the IVC to a sagittal view. If you then tilt into the chest, you should be able to find a long axis view of the IVC entering the RA. Alternately, you can obtain a subxiphoid view of the heart, identify the RA and rotate 90 degrees to find the IVC.

The IVC view is typically thought of in respect to fluid responsiveness in shock. There is little evidentiary support for this practice. We now use the concept of fluid tolerance instead. If the IVC is empty or dynamic, additional fluid volume is unlikely to overload the RV.

A more compelling use of the IVC found in evaluation of obstructive processes. If the IVC is collapsing or dynamic, the patient is not in tamponade.