|SFGH Scanning Protocols
(Adapted from the ACEP Ultrasound Imaging Criteria Compendium)
Detection of pericardial effusion and/or tamponade
Evaluation of gross cardiac activity in the setting of cardiopulmonary resuscitation
Evaluation of global left ventricular systolic function
Gross estimation of intravascular volume status and cardiac preload.
Identification of acute right ventricular dysfunction and/or acute pulmonary hypertension in the setting of acute and unexplained chest pain, dyspnea, or hemodynamic instability.
Identification of proximal aortic dissection or thoracic aortic aneurysm.
Procedural guidance of pericardiocentesis, pacemaker wire placement and capture.
There are no absolute contraindications to cardiac emergency ultrasound (EUS). There may be relative contraindications based on the patient’s clinical situation.
Cardiac EUS is a single component of the overall and ongoing evaluation. Since it is a focused examination EUS does not identify all abnormalities or diseases of the heart. EUS, like other tests, does not replace clinical judgment and should be interpreted in the context of the entire clinical picture. If the findings of the EUS are equivocal additional diagnostic testing may be indicated.
Cardiac ultrasound is capable of identifying many conditions beyond the primary and extended EUS applications listed above. These include but are not limited to: assessment of focal wall motion abnormalities, diastolic dysfunction, valvular abnormalities, intracardiac thrombus or mass, ventricular aneurysm, septal defects, aortic dissection, hypertrophic cardiomyopathy. While these conditions may be discovered when performing cardiac EUS, they are typically outside of the scope of focused cardiac EUS and should typically undergo appropriate consultant-performed imaging for confirmation or follow-up.
Cardiac EUS is technically limited by:
Abnormalities of the bony thorax
The patient’s inability to cooperate with the exam
Phased Array Probe is optimal (A curvilinear probe may suffice if a phased array prove is unavailable)
This view is obtained by placing the probe just under the rib cage or xiphoid process with the transducer directed towards the patient’s left shoulder and the probe marker directed towards the patient’s right (9-o’clock). The liver is used as a sonographic window. The heart lies immediately behind the sternum, so that it is necessary, in a supine patient, to direct the probe in a plane that is almost parallel with the horizontal plane of the stretcher.
This requires firm downward pressure, especially in patients with a protuberant abdomen. Structures imaged in the subcostal four-chamber view include the right atrium, tricuspid valve, right ventricle, left atrium and left ventricle. The pericardial spaces should be examined both anterior and posterior to the heart. By scanning inferiorly, the inferior vena cava may also be visualized as it drains into the right atrium. This can help with orientation, as well as giving information about the patient’s preload and intravascular volume status.
Parasternal Long Axis View
This view is typically obtained using the third, fourth, and fifth intercostal spaces, immediately to the left of the patient’s sternum. Structures imaged on this view include the pericardial spaces (anterior and posterior), the right ventricle, the septum, the left atrium and left ventricular inflow tract, the left ventricle in long axis, the left ventricular outflow tract, the aortic valve, and the aortic root.
The probe marker is directed towards the patient’s right shoulder (approximately 10-o’clock). In this view the aortic outflow and left atrium will be on the left side of the screen as it is viewed and the cardiac apex will be on the right side of the screen.