HAND HELD CARDIAC ULTRASOUND: ROLE IN CLINICAL PRACTICE
Patricia A. Pellikka, M.D.,
Mayo Clinic College of Medicine and Mayo Foundation, Rochester, MN, USA
Technologic advances have resulted in miniaturization of ultrasound systems. Battery-operated, hand-held cardiac ultrasound devices (HHCU) devices weigh less than one pound, fit into the pocket of a laboratory coat, and have been approved by the FDA for cardiac imaging. HHCU are inexpensive compared to full-size ultrasound systems and represent a growing sector of the market. HHCU do not provide zoom functions, spectral Doppler, velocity or time measurements, or electrocardiography interface, and thus, allow limited quantitative information. HHCU have been used to provide point-of-care assessment cardiac assessment in rural and remote community settings. In a health camp in India, studies were uploaded to a cloud-based web server and images reviewed and reports completed by physicians working remotely. Feasibility was excellent; the utility of HHCU in expediting care in remote areas was demonstrated. In a prospective study of 190 adults undergoing comprehensive transthoracic echocardiography, experienced sonographers performed a detailed examination with HHCU. Expert echocardiographers independently reviewed images from the comprehensive transthoracic study and from HHCU and findings were compared. Concordance was good for left ventricular dimensions and chamber size. However, discordant findings were present in 27% of patients. Regional wall motion abnormalities were the most common discordance. HHCU tended to underestimate pathology. The American Society of Echocardiography has recommended that HHCU is most appropriately used as an extension of the physical examination, to address one of several specific clinical questions (e.g., is there left ventricular systolic dysfunction?), and applied when standard echocardiography is not immediately available. Training is required and HHCU must be differentiated from limited transthoracic ultrasound.
Summary: In the hands of experienced users, HHCU correlates well with standard transthoracic echocardiography for certain findings but tends to underestimate the severity of pathology. It is most appropriate as an extension of the physical examination, or when standard transthoracic echocardiography is unavailable.