Cardiology (Quick Guide)

Objectives

  1. Understand the normal anatomy of the heart as it appears in all 4 ultrasound views
  2. Understand the utility of ultrasound as a way of assessing normal or abnormal cardiac function
  3. Be able to quickly and consistently obtain all 4 ultrasound views of the heart
  • Cardiac preset – indicator is on the left of screen
  • Phased array probe
  • Patient in supine position or left lateral decubitus
  • Probe position and indicator unique for each view
    • Rule of pointing toward patient’s right or head not applied
  • Four views to address
    • Parasternal Long Axis
    • Parasternal Short Axis
    • Apical Four Chamber
    • Subxiphoid
Notice how probe angles are a bit different than a typical exam. Don't forget to put the machine on cardiac mode - or your images will be flipped!

First, recall your basic cardiac anatomy and how it sits within the mediastinum. As you translate, fan, and twist the ultrasound probe, you will cut the heart in different planes – keep the basic anatomy in mind!

Anatomy of the Heart for Ultrasound

Since ultrasound doesn’t pierce ribs, the 3rd and 4th intercostal space usually is best for cardiac imaging. Notice the red line and its orientation: your views generally lie either parallel or perpendicular to this line!

 

Lastly, it is important to review the opening and closing of valves during systole and diastole.

  • Systole: aortic + pulmonic valve open
  • Diastole: mitral + tricuspid valve open

The mitral valve is well visualized during exam, and can be key to distinguishing what part of the cardiac cycle you are in.

Reminding yourself of when valves are open and closed can help understand cardiac ultrasound.

  • Acute coronary syndromes
  • Clinically suspected heart failure
  • Unexplained hypotension
  • Pulseless electrical activity (PEA) cardiac arrest
  • Cardiomegaly on physical examination or chest x-ray (CXR)
  • Malignant arrhythmias
  • Cardiac procedures, such as pericardiocentesis

Parasternal Long Axis

Probe Position 

  • Place probe in 4th left intercostal space adjacent to sternum
  • Indicator towards right shoulder

Identify

  • Right and left ventricles
  • Left ventricular outflow tract
  • Aortic valve and mitral valve
  • Left atrium and aorta
  • Pericardium
  • If necessary due to difficulty visualizing the heart, place the patient in the left lateral decubitus position
  • Some will find it easier to start on the sternum and slide to the 4th LICS
  • In this location the right heart is most superficial such that in the US image the right heart is sitting on top of the left heart

Parasternal Short Axis

Probe Position 

  • From parasternal long axis view, rotate probe 90° clockwise (indicator toward left shoulder)

Identify

  • Left ventricle
  • Aortic valve
  • Mitral valve
  • Papillary muscles
  • If necessary due to difficulty visualizing the heart, place the patient in the left lateral decubitus position
  • Angling the probe up towards the base of the heart (opposite of the apex of the heart) will bring the aortic valve into view, which is composed of three cusps which, when they come together, form the “Mercedes Benz” sign
  • Angling the probe towards the apex of the heart, the mitral valve is visualized and looks like the flopping of a fish’s mouth inside the left ventricle
  • Fan back and forth from apex to base to identify the papillary muscles supporting the mitral valve inside the left ventricle

Apical Four Chamber

Probe Position 

  • Place probe on apical impulse, tilted toward the patient’s right shoulder
  • Indicator toward patient’s left lateral chest

Identify

  • All major structures of heart
  • If necessary due to difficulty visualizing the heart, place the patient in the left lateral decubitus position
  • The ventricles sit on top of the atria in this view because the probe is closest to the ventricles at the apex of the heart

Subxiphoid

Probe Position 

  • Place probe right of midline, underneath xiphoid process, acutely angled toward the patient’s left shoulder
  • Indicator toward the left side

Identify

  • All four chambers of heart

[image of scan with all structures identified]

  • A better image is achieved when the patient bends their knees, relaxing the abdominal muscles (left lateral decubitus position will not help scan)
  • It is necessary to apply significant pressure with the probe against the abdominal wall to send the US waves beneath the rib cage
  • The right ventricle is closest to the probe, thus, at the top of the screen