Subcostal four chamber view – Echocardiography

Subcostal four chamber view – EchocardiographySubcostal four chamber view – Echocardiography

Subcostal four chamber view is excellent for visualization of interatrial septum. If an atrial septal dropout is seen in the apical four chamber view, it need not be an atrial septal defect as the IAS is parallel to the ultrasound beam in the apical four chamber view. Structures are imaged well only if they are perpendicular to the ultrasound beam. In case of Doppler, the signals are better when it is parallel to the beam. If the beam is perpendicular to the flow, there is hardly any Doppler signal picked up. Subcostal four chamber view shows right atrium, left atrium, right ventricle and the left ventricle.

The central portion of the IAS is thinner than the rest of it and represents the fossa ovalis region. Secundum atrial septal defect and a patent foramen ovale are seen in this region if present. PFO being a valvular opening, may not be seen always and the flow across the PFO may be noted only in certain phases of respiration or Valsalva maneuver. Pericardial effusion if present, can be easily noted from the subcostal view. The depth at which you are likely to get pericardial fluid for aspiration can also be found out from this view as the usual approach for pericardial aspiration is subxiphoid.

Here is the reference to a good article with line drawings illustrating various echocardiographic views and orientation of cardiac chambers in each view:

  1. Henry WL, DeMaria A, Gramiak R, King DL, Kisslo JA, Popp RL, Sahn DJ, Schiller NB, Tajik A, Teichholz LE, Weyman AE. Report of the American Society of Echocardiography Committee on Nomenclature and Standards in Two-dimensional Echocardiography. Circulation. 1980 Aug;62(2):212-7. (Free full text).