Evaluation of the Aortic Arch from the Suprasternal Notch View Using Focused Cardiac Ultrasound

The suprasternal notch view (SSNV) is an additional echocardiographic view not routinely used by emergency physicians (EPs) performing focused cardiac ultrasound (FOCUS).

This pilot study determined the ease and self-perceived accuracy of the SSNV as performed by EPs. Additionally, we assessed the accuracy of FOCUS including the SSNV in thoracic aortic measurements compared to chest CT angiography (CTA).

This was a prospective, observational, pilot study of adult patients undergoing chest CTA. Thoracic aortic measurements were recorded at the sinus of Valsalva, sinotubular junction, and ascending aorta at its widest diameter in the parasternal long axis (PSL) view and SSNV. EPs rated ease of acquisition and self-perceived accuracy of thoracic aorta measurements. Two blinded radiologists performed thoracic aortic CTA measurements at predefined locations corresponding to the ultrasound measurements.

Of the 79 patients (median age 57 years) enrolled, the SSNV was obtained in 97% of cases. EPs rated the ease of obtaining the SSNV as "easy" in 64.5% of cases and "very difficult" in 7.6% of cases. The mean difference between ultrasound (FOCUS plus SSNV) and CTA measurements were 1.2 mm (95% limits of agreement -2.9 to 5.3) at the sinus of Valsalva, 1.0 mm (95% limits of agreement -5.5 to 3.6 mm) at the sinotubular junction, 0.8 mm (95% limits of agreement -6.2 to 4.6 mm) at the proximal ascending aorta, and 0.6 mm (95% limits of agreement -2.8 to 4.0) at the aortic arch.

Our findings suggest that the SSNV is an easily attainable and accurate view of the thoracic aorta that can be obtained by EPs in the majority of ED patients.