Focused cardiac ultrasound can yield significant diagnostic information for the patient presenting with cardiac arrest, shock, shortness of breath, and a host of other complaints or physical findings. Although the intricacies of comprehensive echocardiography are beyond the scope of practice of most emergency medicine providers, with experience, one can incorporate focused bedside cardiac ultrasound into the diagnostic armamentarium safely to answer specific diagnostic questions such as cardiac activity, volume status, gross cardiac function, right heart strain, and the presence of pericardial effusion.
It is important to note that by convention, unlike abdominal sonography, cardiac ultrasound is viewed with the transducer indicator displayed on the right of the screen. This will require the indicator on the transducer to be directed toward the patient’s left in an anatomically transverse view. This may be disorienting for many who have not performed cardiac ultrasound before. Most ultrasound systems include cardiac presets that automatically reverse the indicator orientation to the right of the display screen. The following section describes a sonographic approach for a conventionally oriented image using standard cardiac windows.
Cardiac arrest, pulseless electrical activity (PEA)
Penetrating thoracic/abdominal trauma
Unexplained hypotension or shock
Acute myocardial infarction
Suspected aortic dissection
Specific pathologic states investigated with bedside cardiac ultrasound include asystole, cardiac activity, pericardial effusion, acute heart failure, aortic root dilatation/dissection, and right heart enlargement.
The sonographic windows for focused cardiac ultrasound include the subxiphoid view presented within the trauma/FAST examination as well as parasternal and apical views. Focused cardiac ultrasound utilizes standard views that are familiar to cardiologists and sonographers alike. These five windows allow the emergency physician to effectively and efficiently evaluate emergent cardiopulmonary pathology.
Views for Focused Cardiac Ultrasound
Subxiphoid/subcostal (SUBX; see “E-FAST Examination, Subxiphoid View”) (Fig. 24.31)
Parasternal long-axis view (PSLA)
Parasternal short-axis view (PSSA)
Apical four-chamber view (AP4)
Subxiphoid long-axis view (IVC)
Focused Cardiac Ultrasound. Transducer and probe marker positions for evaluation of the heart and IVC. (Illustration contributor: Robinson M. Ferre, MD.)
The technique and common findings for each of these views are presented in the next five topics.
The patient should be optimally positioned in the left lateral decubitus position with the left arm above the head (allowing better access to the intercostal spaces) for all but the SUBX and IVC views, which should be performed with the patient supine. If this is not feasible, the patient may be supine for the entire study.