Diagnostic performance of a pocket-sized ultrasound device for quick-look cardiac imaging.

BACKGROUND

Although pocket-sized, simplified ultrasound devices have emerged to enable subjective point-of-care assessment, few data on their cardiac application exist. We sought to examine the image quality and the accuracy of subjective diagnosis of video loops obtained from a pocket-sized ultrasound device for 2 significant cardiac abnormalities, left ventricular systolic dysfunction and left atrial enlargement, obtained from a single, quick-look view.

METHODS

Parasternal left ventricular long-axis images acquired with a miniaturized commercially available device (Acuson P10) were reviewed using subjective criteria for left ventricular systolic dysfunction and left atrial enlargement and were compared with M-mode measurements of left atrial systolic diameter and E-point septal separation from a fully featured echocardiograph in 78 inpatients referred for standard echocardiography. Interpretive confidence and image quality were evaluated with each interpretation.

RESULTS

Of 78 inpatient studies, 19% of pocket ultrasound and 13% of standard studies were technically limited (P = NS). Of 61 technically adequate studies, subjective interpretation of pocket ultrasound images had a sensitivity, specificity, and accuracy of 79%, 52%, and 64% for left atrial diameter more than 4 cm; 47%, 98%, and 82% for E-point septal separation more than 1 cm of; 83%, 62%, and 74% for either abnormality; and 92%, 82%, and 87% for either abnormality when interpretive confidence was present (n = 23). The pocket ultrasound image quality scores were significantly lower than the standard echocardiograph (P < .001).

CONCLUSION

The pocket-sized device provided adequate imaging for screening of 2 significant cardiac entities. Subjective interpretation of a single parasternal view may help identify patients with cardiac disease.